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Testicular torsion is a surgical emergency that occurs in one in 4,000 males under the age of 25.[[1]] Peak incidence of testicular torsion is in the teenage years[[2]] and this may be attributable to increased growth and vascularity of the testicle during puberty. Testicular torsion is usually a sporadic event, with only 4%–8% of cases associated with trauma.[[3]] Intravaginal testicular torsion occurs in males after the perinatal period because of an anatomical anomaly where the tunica vaginalis is attached more proximally on the spermatic cord, which allows it to hang without fixation to the scrotal wall. This is known as the “bell clapper deformity,” which predisposes males to testicular torsion. The incidence of bell clapper deformity was estimated in a cadaver series of 51 males to be approximately 12%.[[4]] For those with an anatomical predisposition for torsion, inflammation and trauma are risk factors.

The two main factors that determine testicle outcome for individuals with torsion are duration of torsion and degree of rotation. Torsion from as early as four hours can result in ischaemia and non-viability if there is sufficient rotation. Testicular ischaemia resulting from over eight hours of torsion has been shown to result in reduced size and abnormal morphology of the affected testicle, as well as reduced endocrine and exocrine function.[[5]] One study found that the degree of testicular atrophy following testicular torsion and orchidopexy was significantly correlated with the duration of pre-operative pain.[[6]] Extensive apoptosis can also be seen in the germinal epithelium of the contralateral testicle in torsion, which may be due to trauma to the blood–testis barrier from apoptotic activating factors released, and may contribute to infertility.[[7]] Therefore timely de-torsion and restoration of blood flow is the key determinant of fertility preservation.

Clinical history and examination are the mainstays in diagnosis of testicular torsion. Classical examination findings include exquisite testicular tenderness, high-riding testicle, swollen testicle and/or absent cremasteric reflex. The lead differential diagnoses include inflammation from epididymitis or orchitis. Other common differential diagnoses include torsion of testicular or epididymal appendage, cellulitis, tumour, hernia or hydrocele.

Ultrasound is a diagnostic tool used to differentiate causes of scrotal pain. Sensitivity and specificity of colour flow Doppler ultrasound in detecting testicular torsion are estimated to be 88.9%–89.9% and 98.8% respectively, with a false-positive rate of 1%.[[8,9]] However, formal ultrasound can delay definitive management in a time-critical situation and lead to worse outcomes. This delay has been associated with worse outcomes in patients with pain longer than eight hours.[[10]] Point-of-care ultrasound by trained emergency department physicians is a demonstrably accurate technique for diagnosis of scrotal pathology and has the potential to streamline patient disposition.[[11]]

This study reviewed adult patients who underwent acute scrotal exploration for suspected torsion at Auckland City Hospital. Patterns of formal ultrasound use were previously unknown in this patient group. The aim was to establish patterns of ultrasound use, correlate ultrasound and intraoperative findings and establish the impact of ultrasound on admission-to-operation time.

Method

All patients who underwent acute scrotal exploration between 1 January 2007 and 31 December 2017 at Auckland City Hospital were identified through the hospital coding system and operating theatre records. Auckland City Hospital provides the regional acute urology service to the Auckland region (total population 1,737,830).[[12]] There were no exclusion criteria. Patients under 15 years of age are served by the paediatric surgical service of the adjacent children’s hospital, and therefore were not included in this study. A de-identified database accessible to the two investigators was created using patient demographic and clinical data sourced from online hospital records. These hospital records included admission and discharge records, theatre documentation, operation notes and ultrasound reports. Demographic data collected included age and ethnicity. Clinical data included side of testicle affected (left or right), admission-to-operation time, intraoperative findings, duration of operation and duration of admission. Whether or not the patient had a formal pre-operative ultrasound scan was documented, along with the time between admission and ultrasound and reported ultrasound findings. A formal ultrasound was one performed by a qualified sonographer and reported by a radiologist. We did not include bedside ultrasound studies. Ultrasound and intraoperative findings were correlated. Admission-to-operation time was compared between patients who had an ultrasound scan and those who did not. Admission-to-operation time was defined as time between arrival at Auckland City Hospital and arrival in the operating theatre. The database was created using Microsoft Excel (Microsoft Corporation 2011, Washington, USA), and patient groups were compared using Pearson’s chi-squared test.[[13]]

Results

The total number of patients who underwent scrotal exploration at Auckland City Hospital between 1 January 2007 and 31 December 2017 was 316.

Patient demographic and clinical data

The median patient age was 18 years (range 15–59). The largest ethnic group was New Zealand European (144/316, 45.6%), followed by Indian (38/316, 12.0%) and Pacific Island (37/316, 11.6%). Median theatre time was 65 minutes (range 27–130). Median duration of admission was 0.93 days (range 0.2–3). Demographic data are summarised in Table 1 and clinical data in Table 2. Intraoperative findings were normal in 27/316 patients (8.5%). Testicular torsion with viable appearance was found in 183/316 patients (57.9%) and testicular torsion with non-viable appearance in 84/316 patients (26.6%). Findings consistent with intermittent torsion were reported in 13/316 patients (4.1%). Table 3 summarises the intraoperative findings for all patients.

Table 1: Demographic data for all study patients.

Table 2: Clinical data for all study patients.

*Total number of patients with finding of abnormal testicle.

Table 3: Summary of intraoperative findings.

Ultrasound

Pre-operative ultrasound was performed in 153/316 patients (48.4%). Testicular torsion with viable appearance was reported in 108/153 patients (70.6%). Testicular torsion with non-viable appearance was reported in 32/153 patients (20.9%). Findings consistent with intermittent torsion were reported in 2/153 patients (1.3%). The following findings were each reported in 1/153 patients (0.7%): epididymo-orchitis, torsion of the epididymis, torsion with epididymitis and infarcted testis without torsion. Normal testicular appearance was reported in 7/153 patients (4.6%).

The median admission-to-operation time was 106 minutes for patients who did not have an ultrasound, and 280 minutes for all patients who did (p<0.0001). When patients who had an ultrasound with finding of missed torsion were excluded from the ultrasound group, the median admission-to-operation time was 225 minutes. The difference between this group and the group who did not have an ultrasound remained significant (p=<0.0001).

Those with missed torsion diagnosed on ultrasound had a much longer median admission-to-operation time than those with all other ultrasound findings (1,046 minutes vs 230 minutes, p=<0.0001). In missed torsion, the testicle becomes no longer salvageable and surgery becomes non-time-critical. These data are summarised in Table 4.

Table 4: Median admission-to-operation time.

*Excluding those with ultrasound finding of missed torsion.

The rate of intraoperative finding of non-viable testicle was significantly higher in the ultrasound group than in the group who did not have an ultrasound (42/122, 34.4% vs 11/163, 6.7%, p=<0.001) when patients with ultrasound showing missed torsion were excluded. Of the patients who did not have an ultrasound, 17/163 (10.4%) had normal testicles intraoperatively, compared with 10/153 (6.5%) of those who had an ultrasound (p=0.22).

Ultrasound sensitivity and specificity for torsion was 97.8% and 52.9%, respectively. The positive predictive value was 94.3% and the negative predictive value was 75%.

Discussion

This study describes the pattern of ultrasound use in suspected testicular torsion in New Zealand’s largest metropolitan area over a 10-year period. It provides a valuable insight into the impact of formal ultrasound on time to re-establishing testicular perfusion in the operating theatre.

In this cohort of patients, ultrasound was shown to be a sensitive test for testicular torsion with a high positive predictive value. Ultrasound sensitivity was higher, but specificity lower, than quoted in the literature.[[8,9]] Approximately half the patients who underwent acute scrotal exploration had a pre-operative ultrasound. Ultrasound was associated with an average two-hour delay to theatre and a four-fold higher intraoperative finding of non-viable testicle, when patients with pre-operative ultrasound diagnosis of missed torsion were excluded.

The onset of ischaemia, as indicated by the onset of pain, will precede hospital admission by a variable duration. The duration of ischaemia prior to admission was not evaluated in this review, but it is important to consider the total ischaemic time as further delays to reperfusion are additive and may have critical impact in preserving testicular structure and function. The four-fold increase in intraoperative finding of non-viable testis in the ultrasound group, even when those with ultrasound diagnosis of missed torsion were excluded, is a concerning association. This is the outcome that timely surgery aims to avoid. Conversely, the low rates of normal testicular findings intraoperatively in both the ultrasound and non-ultrasound groups indicate a relatively high threshold for operative management.

This study only included patients who underwent scrotal exploration, so no comment can be made on the number of operations avoided by negative ultrasound. Therefore neither the utility of ultrasound in patients with low pre-test probability of testicular torsion, nor the rate of false negatives, was assessed. Scrotal exploration has inherent risks of bleeding, infection, chronic pain and injury to scrotal structures. Striking the correct balance between avoiding unnecessary surgery and achieving timely surgery to improve outcomes can be challenging. There was no statistically significant difference in rate of intraoperative finding of normal testicles in patients who had a pre-operative ultrasound compared to those who did not.

This hospital did not have a protocol for when to request an ultrasound for a patient presenting with scrotal pain. This decision was at the discretion of the treating clinician. Therefore a possible source of bias in this study was a lack of consistency in indication for scrotal ultrasound.

This series shows ultrasound to be a highly sensitive test in diagnosis of testicular torsion, making it a valuable tool if obtained in a timely manner. Results show an associated delay to theatre when ultrasound is performed (median), but this delay was not implicit: shortest time from admission to theatre in the ultrasound group was 30 minutes, compared to 42 minutes in the non-ultrasound group.

The descriptive retrospective study by Blavais et al[[11]] described a high sensitivity of emergency physician-performed bedside ultrasound in patients presenting with acute scrotal pain that did not interfere with time to formal ultrasound or theatre. If ultrasound could be performed in a more timely manner, there may still be a role for ultrasound in this setting. However, timely ultrasounds can be constrained by real-world demands on radiology services, particularly after hours, and emergency department clinical demands.

Although ultrasound is a sensitive test for diagnosing testicular torsion, in this centre it was associated with a significant delay to definitive operative management and a higher prevalence of non-viable testis. But this relationship cannot be deemed causative. Testicular torsion is a time-critical pathology where delay to theatre can have an irreversible detrimental effect on fertility. The findings of this study support the notion that ultrasound should not be used as a diagnostic tool when testicular torsion is the likely pathology if it will cause more than a trivial delay in time to theatre.

Summary

Abstract

Aim

Testicular torsion is a surgical emergency and delayed operative management can negatively impact fertility. The aims of this study were to establish patterns of ultrasound use, correlate ultrasound ¬¬and intraoperative findings and determine the impact of ultrasound on admission-to-operation time in patients undergoing scrotal exploration for suspected torsion.

Method

All adult patients who underwent acute scrotal exploration for suspected torsion between 2007 and 2017 at Auckland City Hospital were included (n=316). Clinical notes were reviewed for demographic and clinical data. Admission-to-operation time was compared between patients who had a formal ultrasound and those who did not.

Results

Ultrasound was performed in 153/316 (48.4%) patients. Ultrasound sensitivity and specificity for torsion was 97.8% and 52.9% respectively. Median admission-to-operation time was 106 minutes for patients who did not have an ultrasound and 225 minutes for those who did (excluding those with missed torsion on ultrasound) (p=<0.0001). Non-viable testicle was identified intraoperatively in 11/163 patients (6.7%) who did not have an ultrasound, and in 42/122 (34.4%) of those who did (excluding those with missed torsion on ultrasound) (p=<0.0001).

Conclusion

Ultrasound is a sensitive test for testicular torsion but associated with an average two-hour delay to theatre and a higher rate of intraoperative finding of non-viable testicle in this centre.

Author Information

Hannah Grace Wright: BBioMedSci MBChB, Urology Registrar, Department of Urology, Christchurch Hospital, Canterbury, New Zealand. Hamish John Wright: MBChB, Intensive Care Registrar, Department of Intensive Care, Christchurch Hospital, Canterbury, New Zealand.

Acknowledgements

Correspondence

Hannah Wright, Department of Urology, Christchurch Hospital, 2 Riccarton Avenue, Christchurch Central, Christchurch 8011, New Zealand

Correspondence Email

hanniegrace@gmail.com

Competing Interests

Nil.

1) Barada JH, Weingarten JL, Cromie WJ. Testicular salvage and age-related delay in the presentation of testicular torsion. J Urol. 1989;142(3):746‐748.

2) Lee SM, Huh JS, Baek M, et al. A nationwide epidemiological study of testicular torsion in Korea. J Korean Med Sci. 2014;29(12):1684‐1687.

3) Seng YJ, Moissinac K. Trauma induced testicular torsion: a reminder for the unwary. J Accid Emerg Med. 2000;17(5):381‐382. doi:10.1136/emj.17.5.381

4) Caesar RE, Kaplan GW. Incidence of the bell-clapper deformity in an autopsy series. Urology. 1994;44(1):114‐116.

5) Bartsch G, Frank S, Marberger H, Mikuz G. Testicular torsion: late results with special regard to fertility and endocrine function. J Urol. 1980;124(3):375‐378.

6) Thomas WE, Cooper MJ, Crane GA, Lee G, Williamson RC. Testicular exocrine malfunction after torsion. Lancet. 1984;2(8416):1357‐1360.

7) Hadziselimovic F, Geneto R, Emmons LR. Increased apoptosis in the contralateral testes of patients with testicular torsion as a factor for infertility. J Urol. 1998;160(3 Pt 2):1158‐1160.

8) Kalfa N, Veyrac C, Baud C, Couture A, Averous M, Galifer RB. Ultrasonography of the spermatic cord in children with testicular torsion: impact on the surgical strategy. J Urol. 2004;172(4 Pt 2):1692‐1695.

9) Baker LA, Sigman D, Mathews RI, Benson J, Docimo SG. An analysis of clinical outcomes using color doppler testicular ultrasound for testicular torsion. Pediatrics. 2000;105(3 Pt 1):604‐607.

10) Pryor JL, Watson LR, Day DL, et al. Scrotal ultrasound for evaluation of subacute testicular torsion: sonographic findings and adverse clinical implications. J Urol. 1994;151(3):693‐697.

11) Blaivas M, Sierzenski P, Lambert M. Emergency Evaluation of Patients Presenting with Acute Scrotum Using Bedside Ultrasonography. Acad Emerg Med. 2001;8:90-93.

12) Ministry of Health. NZ Health System. My DHB. [Updated 29 September 2016; cited 20 March 2019]. Available from: https://www.health.govt.nz/new-zealand-health-system/my-dhb.

13) Agresti A. An introduction to categorical data analysis. 2nd ed. New Jersey: John Wiley & Sons, Inc.; 2007.

For the PDF of this article,
contact nzmj@nzma.org.nz

View Article PDF

Testicular torsion is a surgical emergency that occurs in one in 4,000 males under the age of 25.[[1]] Peak incidence of testicular torsion is in the teenage years[[2]] and this may be attributable to increased growth and vascularity of the testicle during puberty. Testicular torsion is usually a sporadic event, with only 4%–8% of cases associated with trauma.[[3]] Intravaginal testicular torsion occurs in males after the perinatal period because of an anatomical anomaly where the tunica vaginalis is attached more proximally on the spermatic cord, which allows it to hang without fixation to the scrotal wall. This is known as the “bell clapper deformity,” which predisposes males to testicular torsion. The incidence of bell clapper deformity was estimated in a cadaver series of 51 males to be approximately 12%.[[4]] For those with an anatomical predisposition for torsion, inflammation and trauma are risk factors.

The two main factors that determine testicle outcome for individuals with torsion are duration of torsion and degree of rotation. Torsion from as early as four hours can result in ischaemia and non-viability if there is sufficient rotation. Testicular ischaemia resulting from over eight hours of torsion has been shown to result in reduced size and abnormal morphology of the affected testicle, as well as reduced endocrine and exocrine function.[[5]] One study found that the degree of testicular atrophy following testicular torsion and orchidopexy was significantly correlated with the duration of pre-operative pain.[[6]] Extensive apoptosis can also be seen in the germinal epithelium of the contralateral testicle in torsion, which may be due to trauma to the blood–testis barrier from apoptotic activating factors released, and may contribute to infertility.[[7]] Therefore timely de-torsion and restoration of blood flow is the key determinant of fertility preservation.

Clinical history and examination are the mainstays in diagnosis of testicular torsion. Classical examination findings include exquisite testicular tenderness, high-riding testicle, swollen testicle and/or absent cremasteric reflex. The lead differential diagnoses include inflammation from epididymitis or orchitis. Other common differential diagnoses include torsion of testicular or epididymal appendage, cellulitis, tumour, hernia or hydrocele.

Ultrasound is a diagnostic tool used to differentiate causes of scrotal pain. Sensitivity and specificity of colour flow Doppler ultrasound in detecting testicular torsion are estimated to be 88.9%–89.9% and 98.8% respectively, with a false-positive rate of 1%.[[8,9]] However, formal ultrasound can delay definitive management in a time-critical situation and lead to worse outcomes. This delay has been associated with worse outcomes in patients with pain longer than eight hours.[[10]] Point-of-care ultrasound by trained emergency department physicians is a demonstrably accurate technique for diagnosis of scrotal pathology and has the potential to streamline patient disposition.[[11]]

This study reviewed adult patients who underwent acute scrotal exploration for suspected torsion at Auckland City Hospital. Patterns of formal ultrasound use were previously unknown in this patient group. The aim was to establish patterns of ultrasound use, correlate ultrasound and intraoperative findings and establish the impact of ultrasound on admission-to-operation time.

Method

All patients who underwent acute scrotal exploration between 1 January 2007 and 31 December 2017 at Auckland City Hospital were identified through the hospital coding system and operating theatre records. Auckland City Hospital provides the regional acute urology service to the Auckland region (total population 1,737,830).[[12]] There were no exclusion criteria. Patients under 15 years of age are served by the paediatric surgical service of the adjacent children’s hospital, and therefore were not included in this study. A de-identified database accessible to the two investigators was created using patient demographic and clinical data sourced from online hospital records. These hospital records included admission and discharge records, theatre documentation, operation notes and ultrasound reports. Demographic data collected included age and ethnicity. Clinical data included side of testicle affected (left or right), admission-to-operation time, intraoperative findings, duration of operation and duration of admission. Whether or not the patient had a formal pre-operative ultrasound scan was documented, along with the time between admission and ultrasound and reported ultrasound findings. A formal ultrasound was one performed by a qualified sonographer and reported by a radiologist. We did not include bedside ultrasound studies. Ultrasound and intraoperative findings were correlated. Admission-to-operation time was compared between patients who had an ultrasound scan and those who did not. Admission-to-operation time was defined as time between arrival at Auckland City Hospital and arrival in the operating theatre. The database was created using Microsoft Excel (Microsoft Corporation 2011, Washington, USA), and patient groups were compared using Pearson’s chi-squared test.[[13]]

Results

The total number of patients who underwent scrotal exploration at Auckland City Hospital between 1 January 2007 and 31 December 2017 was 316.

Patient demographic and clinical data

The median patient age was 18 years (range 15–59). The largest ethnic group was New Zealand European (144/316, 45.6%), followed by Indian (38/316, 12.0%) and Pacific Island (37/316, 11.6%). Median theatre time was 65 minutes (range 27–130). Median duration of admission was 0.93 days (range 0.2–3). Demographic data are summarised in Table 1 and clinical data in Table 2. Intraoperative findings were normal in 27/316 patients (8.5%). Testicular torsion with viable appearance was found in 183/316 patients (57.9%) and testicular torsion with non-viable appearance in 84/316 patients (26.6%). Findings consistent with intermittent torsion were reported in 13/316 patients (4.1%). Table 3 summarises the intraoperative findings for all patients.

Table 1: Demographic data for all study patients.

Table 2: Clinical data for all study patients.

*Total number of patients with finding of abnormal testicle.

Table 3: Summary of intraoperative findings.

Ultrasound

Pre-operative ultrasound was performed in 153/316 patients (48.4%). Testicular torsion with viable appearance was reported in 108/153 patients (70.6%). Testicular torsion with non-viable appearance was reported in 32/153 patients (20.9%). Findings consistent with intermittent torsion were reported in 2/153 patients (1.3%). The following findings were each reported in 1/153 patients (0.7%): epididymo-orchitis, torsion of the epididymis, torsion with epididymitis and infarcted testis without torsion. Normal testicular appearance was reported in 7/153 patients (4.6%).

The median admission-to-operation time was 106 minutes for patients who did not have an ultrasound, and 280 minutes for all patients who did (p<0.0001). When patients who had an ultrasound with finding of missed torsion were excluded from the ultrasound group, the median admission-to-operation time was 225 minutes. The difference between this group and the group who did not have an ultrasound remained significant (p=<0.0001).

Those with missed torsion diagnosed on ultrasound had a much longer median admission-to-operation time than those with all other ultrasound findings (1,046 minutes vs 230 minutes, p=<0.0001). In missed torsion, the testicle becomes no longer salvageable and surgery becomes non-time-critical. These data are summarised in Table 4.

Table 4: Median admission-to-operation time.

*Excluding those with ultrasound finding of missed torsion.

The rate of intraoperative finding of non-viable testicle was significantly higher in the ultrasound group than in the group who did not have an ultrasound (42/122, 34.4% vs 11/163, 6.7%, p=<0.001) when patients with ultrasound showing missed torsion were excluded. Of the patients who did not have an ultrasound, 17/163 (10.4%) had normal testicles intraoperatively, compared with 10/153 (6.5%) of those who had an ultrasound (p=0.22).

Ultrasound sensitivity and specificity for torsion was 97.8% and 52.9%, respectively. The positive predictive value was 94.3% and the negative predictive value was 75%.

Discussion

This study describes the pattern of ultrasound use in suspected testicular torsion in New Zealand’s largest metropolitan area over a 10-year period. It provides a valuable insight into the impact of formal ultrasound on time to re-establishing testicular perfusion in the operating theatre.

In this cohort of patients, ultrasound was shown to be a sensitive test for testicular torsion with a high positive predictive value. Ultrasound sensitivity was higher, but specificity lower, than quoted in the literature.[[8,9]] Approximately half the patients who underwent acute scrotal exploration had a pre-operative ultrasound. Ultrasound was associated with an average two-hour delay to theatre and a four-fold higher intraoperative finding of non-viable testicle, when patients with pre-operative ultrasound diagnosis of missed torsion were excluded.

The onset of ischaemia, as indicated by the onset of pain, will precede hospital admission by a variable duration. The duration of ischaemia prior to admission was not evaluated in this review, but it is important to consider the total ischaemic time as further delays to reperfusion are additive and may have critical impact in preserving testicular structure and function. The four-fold increase in intraoperative finding of non-viable testis in the ultrasound group, even when those with ultrasound diagnosis of missed torsion were excluded, is a concerning association. This is the outcome that timely surgery aims to avoid. Conversely, the low rates of normal testicular findings intraoperatively in both the ultrasound and non-ultrasound groups indicate a relatively high threshold for operative management.

This study only included patients who underwent scrotal exploration, so no comment can be made on the number of operations avoided by negative ultrasound. Therefore neither the utility of ultrasound in patients with low pre-test probability of testicular torsion, nor the rate of false negatives, was assessed. Scrotal exploration has inherent risks of bleeding, infection, chronic pain and injury to scrotal structures. Striking the correct balance between avoiding unnecessary surgery and achieving timely surgery to improve outcomes can be challenging. There was no statistically significant difference in rate of intraoperative finding of normal testicles in patients who had a pre-operative ultrasound compared to those who did not.

This hospital did not have a protocol for when to request an ultrasound for a patient presenting with scrotal pain. This decision was at the discretion of the treating clinician. Therefore a possible source of bias in this study was a lack of consistency in indication for scrotal ultrasound.

This series shows ultrasound to be a highly sensitive test in diagnosis of testicular torsion, making it a valuable tool if obtained in a timely manner. Results show an associated delay to theatre when ultrasound is performed (median), but this delay was not implicit: shortest time from admission to theatre in the ultrasound group was 30 minutes, compared to 42 minutes in the non-ultrasound group.

The descriptive retrospective study by Blavais et al[[11]] described a high sensitivity of emergency physician-performed bedside ultrasound in patients presenting with acute scrotal pain that did not interfere with time to formal ultrasound or theatre. If ultrasound could be performed in a more timely manner, there may still be a role for ultrasound in this setting. However, timely ultrasounds can be constrained by real-world demands on radiology services, particularly after hours, and emergency department clinical demands.

Although ultrasound is a sensitive test for diagnosing testicular torsion, in this centre it was associated with a significant delay to definitive operative management and a higher prevalence of non-viable testis. But this relationship cannot be deemed causative. Testicular torsion is a time-critical pathology where delay to theatre can have an irreversible detrimental effect on fertility. The findings of this study support the notion that ultrasound should not be used as a diagnostic tool when testicular torsion is the likely pathology if it will cause more than a trivial delay in time to theatre.

Summary

Abstract

Aim

Testicular torsion is a surgical emergency and delayed operative management can negatively impact fertility. The aims of this study were to establish patterns of ultrasound use, correlate ultrasound ¬¬and intraoperative findings and determine the impact of ultrasound on admission-to-operation time in patients undergoing scrotal exploration for suspected torsion.

Method

All adult patients who underwent acute scrotal exploration for suspected torsion between 2007 and 2017 at Auckland City Hospital were included (n=316). Clinical notes were reviewed for demographic and clinical data. Admission-to-operation time was compared between patients who had a formal ultrasound and those who did not.

Results

Ultrasound was performed in 153/316 (48.4%) patients. Ultrasound sensitivity and specificity for torsion was 97.8% and 52.9% respectively. Median admission-to-operation time was 106 minutes for patients who did not have an ultrasound and 225 minutes for those who did (excluding those with missed torsion on ultrasound) (p=<0.0001). Non-viable testicle was identified intraoperatively in 11/163 patients (6.7%) who did not have an ultrasound, and in 42/122 (34.4%) of those who did (excluding those with missed torsion on ultrasound) (p=<0.0001).

Conclusion

Ultrasound is a sensitive test for testicular torsion but associated with an average two-hour delay to theatre and a higher rate of intraoperative finding of non-viable testicle in this centre.

Author Information

Hannah Grace Wright: BBioMedSci MBChB, Urology Registrar, Department of Urology, Christchurch Hospital, Canterbury, New Zealand. Hamish John Wright: MBChB, Intensive Care Registrar, Department of Intensive Care, Christchurch Hospital, Canterbury, New Zealand.

Acknowledgements

Correspondence

Hannah Wright, Department of Urology, Christchurch Hospital, 2 Riccarton Avenue, Christchurch Central, Christchurch 8011, New Zealand

Correspondence Email

hanniegrace@gmail.com

Competing Interests

Nil.

1) Barada JH, Weingarten JL, Cromie WJ. Testicular salvage and age-related delay in the presentation of testicular torsion. J Urol. 1989;142(3):746‐748.

2) Lee SM, Huh JS, Baek M, et al. A nationwide epidemiological study of testicular torsion in Korea. J Korean Med Sci. 2014;29(12):1684‐1687.

3) Seng YJ, Moissinac K. Trauma induced testicular torsion: a reminder for the unwary. J Accid Emerg Med. 2000;17(5):381‐382. doi:10.1136/emj.17.5.381

4) Caesar RE, Kaplan GW. Incidence of the bell-clapper deformity in an autopsy series. Urology. 1994;44(1):114‐116.

5) Bartsch G, Frank S, Marberger H, Mikuz G. Testicular torsion: late results with special regard to fertility and endocrine function. J Urol. 1980;124(3):375‐378.

6) Thomas WE, Cooper MJ, Crane GA, Lee G, Williamson RC. Testicular exocrine malfunction after torsion. Lancet. 1984;2(8416):1357‐1360.

7) Hadziselimovic F, Geneto R, Emmons LR. Increased apoptosis in the contralateral testes of patients with testicular torsion as a factor for infertility. J Urol. 1998;160(3 Pt 2):1158‐1160.

8) Kalfa N, Veyrac C, Baud C, Couture A, Averous M, Galifer RB. Ultrasonography of the spermatic cord in children with testicular torsion: impact on the surgical strategy. J Urol. 2004;172(4 Pt 2):1692‐1695.

9) Baker LA, Sigman D, Mathews RI, Benson J, Docimo SG. An analysis of clinical outcomes using color doppler testicular ultrasound for testicular torsion. Pediatrics. 2000;105(3 Pt 1):604‐607.

10) Pryor JL, Watson LR, Day DL, et al. Scrotal ultrasound for evaluation of subacute testicular torsion: sonographic findings and adverse clinical implications. J Urol. 1994;151(3):693‐697.

11) Blaivas M, Sierzenski P, Lambert M. Emergency Evaluation of Patients Presenting with Acute Scrotum Using Bedside Ultrasonography. Acad Emerg Med. 2001;8:90-93.

12) Ministry of Health. NZ Health System. My DHB. [Updated 29 September 2016; cited 20 March 2019]. Available from: https://www.health.govt.nz/new-zealand-health-system/my-dhb.

13) Agresti A. An introduction to categorical data analysis. 2nd ed. New Jersey: John Wiley & Sons, Inc.; 2007.

For the PDF of this article,
contact nzmj@nzma.org.nz

View Article PDF

Testicular torsion is a surgical emergency that occurs in one in 4,000 males under the age of 25.[[1]] Peak incidence of testicular torsion is in the teenage years[[2]] and this may be attributable to increased growth and vascularity of the testicle during puberty. Testicular torsion is usually a sporadic event, with only 4%–8% of cases associated with trauma.[[3]] Intravaginal testicular torsion occurs in males after the perinatal period because of an anatomical anomaly where the tunica vaginalis is attached more proximally on the spermatic cord, which allows it to hang without fixation to the scrotal wall. This is known as the “bell clapper deformity,” which predisposes males to testicular torsion. The incidence of bell clapper deformity was estimated in a cadaver series of 51 males to be approximately 12%.[[4]] For those with an anatomical predisposition for torsion, inflammation and trauma are risk factors.

The two main factors that determine testicle outcome for individuals with torsion are duration of torsion and degree of rotation. Torsion from as early as four hours can result in ischaemia and non-viability if there is sufficient rotation. Testicular ischaemia resulting from over eight hours of torsion has been shown to result in reduced size and abnormal morphology of the affected testicle, as well as reduced endocrine and exocrine function.[[5]] One study found that the degree of testicular atrophy following testicular torsion and orchidopexy was significantly correlated with the duration of pre-operative pain.[[6]] Extensive apoptosis can also be seen in the germinal epithelium of the contralateral testicle in torsion, which may be due to trauma to the blood–testis barrier from apoptotic activating factors released, and may contribute to infertility.[[7]] Therefore timely de-torsion and restoration of blood flow is the key determinant of fertility preservation.

Clinical history and examination are the mainstays in diagnosis of testicular torsion. Classical examination findings include exquisite testicular tenderness, high-riding testicle, swollen testicle and/or absent cremasteric reflex. The lead differential diagnoses include inflammation from epididymitis or orchitis. Other common differential diagnoses include torsion of testicular or epididymal appendage, cellulitis, tumour, hernia or hydrocele.

Ultrasound is a diagnostic tool used to differentiate causes of scrotal pain. Sensitivity and specificity of colour flow Doppler ultrasound in detecting testicular torsion are estimated to be 88.9%–89.9% and 98.8% respectively, with a false-positive rate of 1%.[[8,9]] However, formal ultrasound can delay definitive management in a time-critical situation and lead to worse outcomes. This delay has been associated with worse outcomes in patients with pain longer than eight hours.[[10]] Point-of-care ultrasound by trained emergency department physicians is a demonstrably accurate technique for diagnosis of scrotal pathology and has the potential to streamline patient disposition.[[11]]

This study reviewed adult patients who underwent acute scrotal exploration for suspected torsion at Auckland City Hospital. Patterns of formal ultrasound use were previously unknown in this patient group. The aim was to establish patterns of ultrasound use, correlate ultrasound and intraoperative findings and establish the impact of ultrasound on admission-to-operation time.

Method

All patients who underwent acute scrotal exploration between 1 January 2007 and 31 December 2017 at Auckland City Hospital were identified through the hospital coding system and operating theatre records. Auckland City Hospital provides the regional acute urology service to the Auckland region (total population 1,737,830).[[12]] There were no exclusion criteria. Patients under 15 years of age are served by the paediatric surgical service of the adjacent children’s hospital, and therefore were not included in this study. A de-identified database accessible to the two investigators was created using patient demographic and clinical data sourced from online hospital records. These hospital records included admission and discharge records, theatre documentation, operation notes and ultrasound reports. Demographic data collected included age and ethnicity. Clinical data included side of testicle affected (left or right), admission-to-operation time, intraoperative findings, duration of operation and duration of admission. Whether or not the patient had a formal pre-operative ultrasound scan was documented, along with the time between admission and ultrasound and reported ultrasound findings. A formal ultrasound was one performed by a qualified sonographer and reported by a radiologist. We did not include bedside ultrasound studies. Ultrasound and intraoperative findings were correlated. Admission-to-operation time was compared between patients who had an ultrasound scan and those who did not. Admission-to-operation time was defined as time between arrival at Auckland City Hospital and arrival in the operating theatre. The database was created using Microsoft Excel (Microsoft Corporation 2011, Washington, USA), and patient groups were compared using Pearson’s chi-squared test.[[13]]

Results

The total number of patients who underwent scrotal exploration at Auckland City Hospital between 1 January 2007 and 31 December 2017 was 316.

Patient demographic and clinical data

The median patient age was 18 years (range 15–59). The largest ethnic group was New Zealand European (144/316, 45.6%), followed by Indian (38/316, 12.0%) and Pacific Island (37/316, 11.6%). Median theatre time was 65 minutes (range 27–130). Median duration of admission was 0.93 days (range 0.2–3). Demographic data are summarised in Table 1 and clinical data in Table 2. Intraoperative findings were normal in 27/316 patients (8.5%). Testicular torsion with viable appearance was found in 183/316 patients (57.9%) and testicular torsion with non-viable appearance in 84/316 patients (26.6%). Findings consistent with intermittent torsion were reported in 13/316 patients (4.1%). Table 3 summarises the intraoperative findings for all patients.

Table 1: Demographic data for all study patients.

Table 2: Clinical data for all study patients.

*Total number of patients with finding of abnormal testicle.

Table 3: Summary of intraoperative findings.

Ultrasound

Pre-operative ultrasound was performed in 153/316 patients (48.4%). Testicular torsion with viable appearance was reported in 108/153 patients (70.6%). Testicular torsion with non-viable appearance was reported in 32/153 patients (20.9%). Findings consistent with intermittent torsion were reported in 2/153 patients (1.3%). The following findings were each reported in 1/153 patients (0.7%): epididymo-orchitis, torsion of the epididymis, torsion with epididymitis and infarcted testis without torsion. Normal testicular appearance was reported in 7/153 patients (4.6%).

The median admission-to-operation time was 106 minutes for patients who did not have an ultrasound, and 280 minutes for all patients who did (p<0.0001). When patients who had an ultrasound with finding of missed torsion were excluded from the ultrasound group, the median admission-to-operation time was 225 minutes. The difference between this group and the group who did not have an ultrasound remained significant (p=<0.0001).

Those with missed torsion diagnosed on ultrasound had a much longer median admission-to-operation time than those with all other ultrasound findings (1,046 minutes vs 230 minutes, p=<0.0001). In missed torsion, the testicle becomes no longer salvageable and surgery becomes non-time-critical. These data are summarised in Table 4.

Table 4: Median admission-to-operation time.

*Excluding those with ultrasound finding of missed torsion.

The rate of intraoperative finding of non-viable testicle was significantly higher in the ultrasound group than in the group who did not have an ultrasound (42/122, 34.4% vs 11/163, 6.7%, p=<0.001) when patients with ultrasound showing missed torsion were excluded. Of the patients who did not have an ultrasound, 17/163 (10.4%) had normal testicles intraoperatively, compared with 10/153 (6.5%) of those who had an ultrasound (p=0.22).

Ultrasound sensitivity and specificity for torsion was 97.8% and 52.9%, respectively. The positive predictive value was 94.3% and the negative predictive value was 75%.

Discussion

This study describes the pattern of ultrasound use in suspected testicular torsion in New Zealand’s largest metropolitan area over a 10-year period. It provides a valuable insight into the impact of formal ultrasound on time to re-establishing testicular perfusion in the operating theatre.

In this cohort of patients, ultrasound was shown to be a sensitive test for testicular torsion with a high positive predictive value. Ultrasound sensitivity was higher, but specificity lower, than quoted in the literature.[[8,9]] Approximately half the patients who underwent acute scrotal exploration had a pre-operative ultrasound. Ultrasound was associated with an average two-hour delay to theatre and a four-fold higher intraoperative finding of non-viable testicle, when patients with pre-operative ultrasound diagnosis of missed torsion were excluded.

The onset of ischaemia, as indicated by the onset of pain, will precede hospital admission by a variable duration. The duration of ischaemia prior to admission was not evaluated in this review, but it is important to consider the total ischaemic time as further delays to reperfusion are additive and may have critical impact in preserving testicular structure and function. The four-fold increase in intraoperative finding of non-viable testis in the ultrasound group, even when those with ultrasound diagnosis of missed torsion were excluded, is a concerning association. This is the outcome that timely surgery aims to avoid. Conversely, the low rates of normal testicular findings intraoperatively in both the ultrasound and non-ultrasound groups indicate a relatively high threshold for operative management.

This study only included patients who underwent scrotal exploration, so no comment can be made on the number of operations avoided by negative ultrasound. Therefore neither the utility of ultrasound in patients with low pre-test probability of testicular torsion, nor the rate of false negatives, was assessed. Scrotal exploration has inherent risks of bleeding, infection, chronic pain and injury to scrotal structures. Striking the correct balance between avoiding unnecessary surgery and achieving timely surgery to improve outcomes can be challenging. There was no statistically significant difference in rate of intraoperative finding of normal testicles in patients who had a pre-operative ultrasound compared to those who did not.

This hospital did not have a protocol for when to request an ultrasound for a patient presenting with scrotal pain. This decision was at the discretion of the treating clinician. Therefore a possible source of bias in this study was a lack of consistency in indication for scrotal ultrasound.

This series shows ultrasound to be a highly sensitive test in diagnosis of testicular torsion, making it a valuable tool if obtained in a timely manner. Results show an associated delay to theatre when ultrasound is performed (median), but this delay was not implicit: shortest time from admission to theatre in the ultrasound group was 30 minutes, compared to 42 minutes in the non-ultrasound group.

The descriptive retrospective study by Blavais et al[[11]] described a high sensitivity of emergency physician-performed bedside ultrasound in patients presenting with acute scrotal pain that did not interfere with time to formal ultrasound or theatre. If ultrasound could be performed in a more timely manner, there may still be a role for ultrasound in this setting. However, timely ultrasounds can be constrained by real-world demands on radiology services, particularly after hours, and emergency department clinical demands.

Although ultrasound is a sensitive test for diagnosing testicular torsion, in this centre it was associated with a significant delay to definitive operative management and a higher prevalence of non-viable testis. But this relationship cannot be deemed causative. Testicular torsion is a time-critical pathology where delay to theatre can have an irreversible detrimental effect on fertility. The findings of this study support the notion that ultrasound should not be used as a diagnostic tool when testicular torsion is the likely pathology if it will cause more than a trivial delay in time to theatre.

Summary

Abstract

Aim

Testicular torsion is a surgical emergency and delayed operative management can negatively impact fertility. The aims of this study were to establish patterns of ultrasound use, correlate ultrasound ¬¬and intraoperative findings and determine the impact of ultrasound on admission-to-operation time in patients undergoing scrotal exploration for suspected torsion.

Method

All adult patients who underwent acute scrotal exploration for suspected torsion between 2007 and 2017 at Auckland City Hospital were included (n=316). Clinical notes were reviewed for demographic and clinical data. Admission-to-operation time was compared between patients who had a formal ultrasound and those who did not.

Results

Ultrasound was performed in 153/316 (48.4%) patients. Ultrasound sensitivity and specificity for torsion was 97.8% and 52.9% respectively. Median admission-to-operation time was 106 minutes for patients who did not have an ultrasound and 225 minutes for those who did (excluding those with missed torsion on ultrasound) (p=<0.0001). Non-viable testicle was identified intraoperatively in 11/163 patients (6.7%) who did not have an ultrasound, and in 42/122 (34.4%) of those who did (excluding those with missed torsion on ultrasound) (p=<0.0001).

Conclusion

Ultrasound is a sensitive test for testicular torsion but associated with an average two-hour delay to theatre and a higher rate of intraoperative finding of non-viable testicle in this centre.

Author Information

Hannah Grace Wright: BBioMedSci MBChB, Urology Registrar, Department of Urology, Christchurch Hospital, Canterbury, New Zealand. Hamish John Wright: MBChB, Intensive Care Registrar, Department of Intensive Care, Christchurch Hospital, Canterbury, New Zealand.

Acknowledgements

Correspondence

Hannah Wright, Department of Urology, Christchurch Hospital, 2 Riccarton Avenue, Christchurch Central, Christchurch 8011, New Zealand

Correspondence Email

hanniegrace@gmail.com

Competing Interests

Nil.

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