Journal of the New Zealand Medical Association, 12-December-2008, Vol 121 No 1287
A prospective study analysing the effect of pain on probe insertion, and the biopsy strategy, on the patients’ perception of pain during TRUS-guided biopsy of the prostate
Samarth Chopra, Edward W J Rowe, Marc Laniado, Anup Patel
The advent of PSA as a tumour marker for early impalpable prostate cancer has inevitably led to an escalation in the number of transrectal ultrasound (TRUS)-guided biopsies of the prostate. For the majority of men, TRUS biopsy of the prostate seems to be well tolerated. However, previous studies have demonstrated that a significant proportion of men find the procedure painful.
One study of 104 men found that 24% experienced moderate to extreme pain when between 4 and 8 biopsies were performed,1 while others demonstrated that 19% of men would not wish to undergo the procedure again without some form of analgesia.2
Avoidance of pain in men undergoing TRUS biopsy of the prostate is of course desirable, not only for the obvious concerns over patient well being, but there is also a danger that the procedure may be rushed or even abandoned in a patient experiencing a high degree of discomfort, along with a reluctance on the part of the patient to return for future biopsies when necessary.2 This has lead to some centres recommending the routine use of analgesia. However, the proposed benefits of the various forms of local anaesthesia for TRUS-guided prostate biopsy3,4 are neither universally accepted,5 nor widely available.
It could also be argued that giving local anaesthetic to all patients is unnecessary for a procedure that is well tolerated with minimal discomfort in the majority of men. In this study we considered those factors which may enable the clinician to predict which men are likely to suffer severe pain during the biopsy. There are studies suggesting that the degree of pain is directly proportional to the number of biopsy cores obtained,6 though these claims are refuted in a more recent prospective randomised trial.7
In this prospective, non-randomised study we aimed to ascertain whether the proportion of men in whom the biopsies resulted in severe pain could be predicted on the basis of their reported pain on insertion of the biopsy probe alone, and also whether severe pain is directly related to the number of biopsy cores taken.
Consecutive men attending for prostate biopsy were recruited in this study. and included both screened and symptomatic patients. Each received a letter giving details of the procedure together with potential complications, along with a cleansing enema, and three day course of a prophylactic antibiotic (Levofloxacin 250 mg), commenced on the morning of the procedure.
The procedure was performed with the patient in the left lateral decubitus position. All samples were obtained using an 18G spring loaded disposable Tru-cut needle (Microvasive) under TRUS guidance using a Bruel & Kjaer Medical (Leopard, Type 2001) ultrasound scanner with a 6.0 to 7.5MHz endosonic multiplane transducer probe (Type 8551).
The number of biopsies taken were determined by the total prostate volume. A standard peripheral zone sextant biopsy was performed on prostates up to 30 cm.3 Those with a prostate volume between 30.1 and 39.9cm3 received between 7–11 (median 8) biopsies, and all men with a volume of >40 cm3 underwent a 12 core strategy consisting of the standard peripheral zone sextant regime with a further 6 laterally place cores.
The first biopsy was always taken from the right apex of the gland, and the last from the left base. All procedures were performed by ER (Research Fellow) 75.5%, or AP (Consultant Urologist) 24.5%. None of the patients received local anaesthetic or sedation.
Each patient completed a linear 10-point visual analogue score (VAS) within 2 to 5 minutes of the procedure indicating their pain at three time points:
An enquiry was made of current or previous perianal disease. There is no clear consensus on the exact definition of severe pain on the VAS.2 However, following observations and discussion with men who had previously undergone TRUS prostate biopsy, we arbitrarily defined severe pain (deemed unacceptable) as a VAS score of 8 to 10.
Chi-squared for trend was used to determine whether the number of biopsies was associated with severe pain. We also assessed the association of severe pain on insertion of the TRUS probe and subsequent pain scores during the biopsy process (Fisher’s exact test). (CI = 95% confidence interval).
Men had a mean age of 61.7 years (SD 6.8 years). Indications for biopsy were abnormal total PSA (n=135), or DRE (n=27). Median PSA was 5.7 ng/ml. Of the 162 men biopsied, 22% (36/162) found the procedure unacceptably painful (VAS score 8 to 10) in one or more of the three categories.
There was a general increase in the incidence of severe pain scores from the first to the last biopsy, irrespective of the strategy employed (Table 1). There was also a higher incidence of severe pain overall for the whole procedure experienced by men undergoing a 12-core strategy compared to those receiving a 7–11 core or sextant biopsy.
Table 1. Percentage of men experiencing unacceptable pain (VAS 8–10)
(p=0.05, Chi-squared for linear trend).
The increasing trend in mean pain scores from the first to the last biopsy, and with increasing numbers of biopsy cores obtained, did not reach statistical significance (Table 2).
A minority of men, 6% (9/162) found initial insertion of the TRUS probe unacceptably painful (None had a documented pre-existing painful perianal condition). Of this group, 78% (7/9, CI 40 to 97%) experienced severe pain later during the biopsy procedure itself, compared to 19% (29/152, CI 13 to 26%) who did not find probe insertion severely painful (difference = 59%, CI = 25% to 76%, p<0.0001, exact test for two independent proportions).
There were no differences in pain scores between the clinicians performing the biopsies.
Table 2. Mean pain scores according to sampling
(p=0.3; Chi-squared for linear trend).
This study has shown that one in five men have severe pain at the time of TRUS biopsy, there is a trend towards greater pain overall with the number of biopsies taken, and, for the first time, that pain on insertion of the TRUS probe is a significant predictor of severe pain overall.
The incidence of severe pain is consistent with previous studies in which 24% of men experienced moderate or extreme pain.1 Naughton et al found a significant increase in pain recall at 2 weeks following the procedure, which persisted at 4 weeks.7 It is therefore likely that number of men reporting severe pain during the procedure would have been even higher than our figure of 22% if completion of the VAS had taken place in the weeks following the TRUS biopsy. This has implications for future patient compliance when repeat prostate sampling is necessary.
Earlier randomised studies comparing 12 core sampling and the standard sextant technique, demonstrated a higher mean pain score in the 12 core group, but the differences between the two regimes did not reach statistical significance.7 Our results are consistent with this study in terms of mean pain scores. However, the incidence of severe pain is significantly higher when a biopsy strategy incorporating more cores is adopted. The finding of an increased incidence of severe pain from the first to the last biopsy would appear to further support the notion that the severity of pain is related the number of biopsies performed.
Of the men in whom insertion of the probe resulted in severe pain, a high proportion (78%) experienced unacceptable levels of pain during the biopsy process itself. To our knowledge this is the most reliable indicator of men likely to experience severe pain during the biopsy process. Real time VAS pain assessment would allow identification of this cohort of men.
The proposed benefits of local/general anaesthesia could then be discussed with the patient. This has the potential to reduce the incidence of severe pain during core acquisition in 20% (7/36) who might be expected to experience severe pain.
The form of analgesia and its efficacy remain controversial. One study analysing the effect of lidocaine gel found it had no impact on the tolerance of TRUS biopsy,8 while a more recent study of 63 men suggested it was a safe and efficacious method of providing satisfactory anaesthesia.9
Though the of use prostatic nerve blockade described in 19963 is disputed by some,5 there is recent evidence from randomised double-blind placebo controlled studies that periprostatic lignocaine infiltration is a safe and effective means of reducing pain at TRUS biopsy of the prostate.10
As the majority of patients do not experience severe pain during the procedure, many studies have been underpowered do detect relevant reductions in severe pain if pain scores have been compared in all patients. Clearly not all men experience severe pain during the procedure, and a uniform policy of administering a local anaesthetic periprostatic nerve block risks over treatment of the vast majority of men undergoing TRUS biopsy, with associated cost implications.
Limitations of this study include the non-randomised structure and that the observers collecting pain scores were not blinded to the number of biopsies taken as were the patients. Evidence for this is that more patients had severe pain at the first biopsy if they were about to have 12 biopsies than 6. This might explain why patients felt they had more pain overall if 12 biopsies were taken rather than 6.
TRUS prostate biopsy is becoming increasingly common. We have identified one group of men in whom prediction of severe pain is possible. With trend towards saturation Biopsies the need for predicting group of men who will need local/general anaesthesia is ever-increasing.
Competing interests: None known.
Author information: Samarth Chopra, Urology Registrar, Palmerston North Hospital, Palmerston North, New Zealand; Edward W J Rowe, Consultant Urologist, North Bristol Hospital, Bristol, England; Marc Laniado and Anup Patel, Consultant Urologists, St Mary’s Hospital NHS Trust, London, England
Correspondence: Mr S Chopra, 2 Celtic Court, Palmerston North 5301, New Zealand. Email: firstname.lastname@example.org
issue | Search journal |
Archived issues | Classifieds
| Hotline (free ads)
Subscribe | Contribute | Advertise | Contact Us | Copyright | Other Journals