The use of anaesthetic for transrectal ultrasound-guided prostate biopsy

Introduction

Prostate cancer is the most common male cancer in the UK, accounting for nearly a quarter of all new male cancer diagnoses. Each year around 10,200 men die from prostate cancer. ¹ Much of the increase in incidence is due to the incidental discovery of prostate cancer following transurethral resection of the prostate and more recently the use of prostate-specific antigen (PSA) testing. Survival and treatment options of prostate cancer are related to disease extent/stage and histological differentiation (grade) using the Gleason System. ² Advances in biopsy instruments, i.e. spring-loaded biopsy needles, have dramatically improved the ease, simplicity and accuracy of prostate biopsy (PB). Transrectal ultrasound-guided prostate biopsy (TRUS-GPB) is now a well-established routine urological outpatient procedure. It has been routinely performed without analgesia in most centres. Tolerated by many, it can be associated with significant pain for some. ³ Since the incidence of detected cancer seems to correlate with the number of cores, the amount of pain may increase with the number of cores obtained. ⁴ Thus, there is a need for a simple method of pain relief. One of the most commonly reported techniques is the periprostatic nerve block with local anaesthetic (LA) – lidocaine – injection. This was introduced as early as 1996 by Nash et al. ⁵ This was inspired by Reddy, ⁶ who described a technique of transperineal prostatic nerve blockade in which LA was injected along the lateral edge of the prostate and at the junction of the prostate and seminal vesicle (SV) for transurethral balloon dilatation of the prostate.

Until 2000, TRUS-GPB was usually performed with no pain relief and perceived as a well-tolerated technique. During the last 10 years, there has been a growing awareness of the need to adopt analgesia/anaesthesia in clinical practice, and an increasing number of studies have been published. Some studies have negative and inconclusive results. ^7,8 Our study provides additional evaluation of the effect of administering LA thus allowing further analysis of the efficacy of analgesia.

The current NHS Prostate Cancer Risk Management Programme (PCRMP) guidelines of TRUS-GBP are based on results of a conference held in June 2003 at the Royal College of Pathologists in London. ⁹ The routine use of LA was recommended as a safe procedure in reducing pain/discomfort relating to the prostate biopsy. The anticipation of pain is a major source of patient anxiety and a potential deterrent for undergoing the procedure. Minimization of patient discomfort is an important clinical consideration. However, no consensus has been reached regarding anaesthetic use.

Methods

All patients referred to the radiology department of the base hospital with an abnormal digital rectal exam and raised PSA for a TRUS-GPB were eligible for inclusion in the study. Ethical approval was obtained from the County Durham and Tees Valley 1 Research Ethics Committee (07/HO905/103). A total of 75 consecutive men were recruited over a six-month period from 28 January 2008 to July 2008. A single-centre, quantitative comparative study design was used. It was a prospective study using historical controls, i.e. it was standard practice for patients to receive a questionnaire as part of a continuous audit of patient experience and tolerability. Therefore, the questionnaire results without the use of LA received in the previous six months prior to 28 January 2008 (i.e. 28 July 2007–28 January 2008) were used as a comparison. The questionnaire, with the use of LA, was modified slightly to fulfil the aims of the study by including age stratification and admission into hospital as a measure of septicaemia.

Exclusion criteria included patients with known lidocaine allergy, bleeding diathesis, ano-rectal disease/painful anal conditions, history of radical prostatectomy and radiotherapy. Patients were counselled and informed written consent was obtained for the procedure and participation in the study.

All the TRUS-GPBs were performed in an identical manner, by two sonographers using the same equipment, ultrasound machine and transrectal transducer. Both practitioners adhered to the same technique obviating any variability. Patients were placed in the left lateral decubitus position. Vital signs were monitored. Digital rectal examination (DRE) was performed prior to transducer insertion. The transducer was covered by a double disposable sterile sheath with the biopsy guide attachment and lubricating gel. It was gently advanced into the rectum to the base of the bladder until the SVs were visualized. The prostate appears as an ovoid hypoechoic structure. The prostate was assessed in both transverse and sagittal planes, beginning at the base of the gland extending to the apex, noting any asymmetry, location and characteristics of any lesions. Prostate volume was documented. SVs were imaged assessing for invasion with loss of the SV fat angle. Hard copy images were taken.

LA, lidocaine hydrochloride (10 mL 1%), was administered just before the biopsies through a single puncture on each side. A 20 cm 22 G spinal needle was inserted through the needle guide under TRUS guidance. The tip of the needle seen as a linear hyperechoic focus was advanced into the right side of the gland at the apex. The needle was then slowly withdrawn under direct vision and once immediately outside the prostate capsule 5 mL of lidocaine was dissipated into the fat plane, i.e. Denonvillier's fascia (Figure 1) avoiding intravenous injection. The position of the needle was confirmed by the lack of resistance while injecting and by visual confirmation of the anaesthetic fluid. OPEN IN VIEWER

The biopsy was obtained using an automatic spring-loaded 18 G, 20 cm-long core biopsy gun passed through the needle guide attached to the ultrasound transducer. A total of eight core biopsies were taken in sequence systematically through the left and right peripheral zones from the base, mid- and apex of the gland with individual basketting of tissue samples. Continuous reassurance was given by the practitioner, nurse and assistant.

A 1 g metronidazole suppository was administered immediately following the procedure. A two-day course of ciprofloxacin was prescribed. Written and verbal information about the complications of haematuria, haematospermia, haematochezia and prostatitis were given. Patients were advised to attend A&E or visit their general practitioner (GP) if symptoms arose.

Immediately following the procedure patients were given a self-administered validated questionnaire to complete, to be returned at their two-week follow-up appointment in the urology outpatients department. An addressed envelope was provided for patients to return the questionnaire. As the primary aim was to assess pain, patients were asked to grade their overall pain score associated with the procedure using the visual analogue scale (VAS)/numerical rating scale ranging from 0 to 10. Secondary aims, i.e. duration and severity of the known side-effects, were assessed by recording the presence and duration of three bleeding complications: haematuria, haematochezia and haematospermia.

Results

Discussion

Regarding pain and tolerability, TRUS-GPB is routinely performed without any form of anaesthesia and although some urologists may perceive the procedure as ‘uncomfortable’, patients often regard it as ‘painful’. ^10,11 The perception of pain is notoriously hard to quantify and the interpretation of results remains subjective. ¹² Due to its sensitivity and the ability for statistical comparison, the VAS has become widely accepted as the best method for the subjective measurement of pain and was used in this comparative study. ^13,14 Along with the VAS scale this study incorporated broad-based parameters by assessing pain on a descriptive scale (i.e. ‘tolerable’ ‘uncomfortable’ and ‘painful’) as well as a descriptive morbidity profile. The International Association for the Study of Pain suggests that effective pain management should result in a pain score of less than 3. ¹⁵ This study reports that even without the use of LA the mean pain score was only 3.7 and reduced to 2.3 with the use of LA. This reduction of 1.4 is statistically significant (P = <0.05). Furthermore, other studies have reported that if the baseline pain score is >3, a range of 1.3 has been indicated as the threshold for minimal relief; using this criterion, the current study indicates the use of LA is also clinically significant. ¹⁶ Patients’ acceptance of re-biopsy was used as an additional measurement of pain evaluation with no significant difference between the two groups being demonstrated as 98% of the non-LA group agreed to a repeat biopsy if necessary.

Variability in operator technique will surely affect pain perception and potentially bias the outcomes. The expertise, training and dexterity of the operator play a fundamental role in the perceived discomfort throughout the procedure. This was addressed by using two experienced sonographers and a standardized technique.

Multiple techniques have been reported regarding the infiltration of LA in terms of the location, amount and number of injections. This study infiltrated 5 mL of 1% lidocaine into the prostate apex bilaterally, which has been reported as an effective technique allowing the 10 mL bolus to extend up to the SVs under Denonvilliers fascia. ¹⁷ This technique also minimized the number of punctures to only two, which is relevant as some research reports infiltration of the LA as the most painful aspect of the procedure. ^18–20

The importance of reassuring and comforting the patient was highlighted by the results. Almost all (98%) patients stated that the presence of a health-care assistant to reassure and alleviate their anxiety was beneficial in making the procedure more tolerable.

The complications and morbidity associated with TRUS-GPB are well established with sepsis being the most serious potential complication. Severe haemorrhage requiring hospitalization occurs in less than 1%. ²¹ The most common complication is mild self-limiting bleeding (haematuria, haematochezia and haematospermia). ²² Despite other published studies reporting no increase regarding the incidence of bleeding related to LA, the result of this study reported a statistically significant increase in the rate of haematochezia and haematospermia in the LA group; however, the magnitude of this association was weak. ^23,24 Larger studies with the use of LA may be required to assess further the significance of bleeding incidences. The presence of haematospermia is likely to be skewed as some men may have not ejaculated over the study period and others only once. There was no statistically significant difference with regard to infection in terms of fever and hospitalization in the two groups. However, infection in this study was not precisely defined, i.e. patients were requested to visit their GP if they had fever or a general feeling of being unwell. The GP would extend the course of antibiotics for a further five days.

This study was conducted in response to clinical practice guidelines produced by the National Health Service, which advocated the use of LA as best practice during TRUS-GPB. At the time of writing, in the authors’ institution LA was not routinely offered as experience dictated that patients tolerated the procedure well without anaesthesia. However, this study has established that a large number of men experience pain and that infiltration of periprostatic LA greatly reduced this and increased the tolerability of the procedure with no significant additional morbidity.

A number of limitations to this study are acknowledged. The main limitation was the study design. The original aim was a prospective, randomized, double-blind, placebo-controlled trial but due to financial, temporal and ethical constraints this was not possible. Randomized controlled trials are the most rigorous form of experimental design and considered the gold standard. Possible bias for the retrospective quantification of pain is recognized. The original retrospective questionnaire did not record patient age, therefore a direct comparison between the groups is not possible.

Conclusion

LA is simple and easy to administer, quick and cost-effective. This study supports the use of LA in TRUS-GPB and the local working practice has subsequently changed. The increase in tolerability permits an increased number of core biopsies with no extra discomfort to the patient.

Although continuous refinement of the biopsy procedure has been introduced over the years, discomfort continues to be the most common side-effect and any new technique to alleviate this is welcome. Further qualitative and quantitative research is required to explore men's perceptions at ameliorating prostate biopsy-related pain/discomfort but, in the meantime, TRUS-GPB is a safe outpatient procedure which can be made less unpleasant with effective pain relief.

DECLARATIONS

Competing interests: None.

Funding: Not applicable.

Ethical Approval: The Northern Research Ethics committee of County Durham and Tees Valley 1 approved this study (REC number: 07/H0905/103). Also approved by the hospitals Research and Development department.

Guarantor: KJ.

Contributorship: KJ, GN and DC conceived the study, were involved in protocol development. KJ researched literature, gained ethical approval, involved in patient recruitment, data analysis and wrote the first draft of the manuscript. All authors reviewed and edited the manuscript and approved the final version of the manuscript.

Acknowledgements: We would like to thank Helen Scullion (Urology Advanced Nurse Practitioner) for her invaluable assistance, involvement in patient recruitment and data collection. We would also like to thank Sylvia Storey (Senior Lecturer in Research methods at Teesside University) and Maya Harris (Urology Specialist) in their invaluable help in the statistical analysis and Simon Richards (Ultrasound Programme Leader, Teesside University) for his guidance in this research.