Annals of the Royal College of Surgeons of England (1979) vol 6i
ASPECTS OF TREATMENT*
Prostatectomy at a district general hospital R D Leach FRCS Surgical Registrar, Kingston upon Thames Hospital, Surreyt
Summary The mortality and morbidity in 6oo patients undergoing prostatectomy at a district general hospital are reviewed. Below the age of 70 years the operative mortality was I 7% compared with an overall mortality of 2.3%. Cardiorespiratory disease accounted for the majority of deaths. The increase of postoperative stay due to complications may be reduced by lowering the complication rate and, in the long term, reducing pre-existing cardiorespiratory disease. Introduction One man in i o may expect to undergo surgery for prostatic enlargement', but whether or not this should always be performed in urological units is still subject to controversy. Surgeons at district general hospitals have performed prostatectomy for many years even if the techniques employed by them have become less fashionable. Eighty per cent of prostatectomies in the United Kingdom are performed by open operation and often by surgeons with no specialist urological training2. This is confirmed by the experience at Kingston Hospital, which serves a population of 250 ooo and has no specialist urologist. Between 1970 and 1976 6oo prostatectomies were performed by 4 consultant surgeons and their junior staff. The results and complications of these operations are presented to affirm the position of prostatectomy at district general hospitals. Presentation and indications for surgery Prostatectomy was performed for acute retention in 350 cases (58.37), for chronic retention in 52 (8.7 %), and for prostatism in I98 (33 %).
Emergency presentation, however, accounted for 356 cases (597C); these patients were sent by family doctors, presented themselves at the Accident and Emergency Department, or were referred by other departments in the hospital. Acute retention of urine occurred in 30 patients (5 Co) following non-urological surgery and required prostatectomy during the same admission. The incidence of urinary outflow obstruction symptoms was as follows: poor stream 6 7%, frequency 66 %o, nocturia 6 Io, hesitancy 5270, dysuria I 970, and urgency i 6o . Haematuria occurred in 6o patients (i o o), in whom engorged prostatic veins were the only cause found. The mean age of the patients was 69.3 (3895) years. There were 441 (73.570) between 6o and 79 and 8i (I3.570) over 8o.
Surgical procedures
Each patient was carefully examined endoscopically and bimanually under anaesthesia. Open prostatectomy was performed in 48 I cases (80.270) and of these operations, 4I7 (69.570 of the total) were retropubic prostatectomies and 64 (I0.7 7o) transvesical. Retropubic prostatectomy was performed by Millin's method3, although there were minor variations in technique. The transvesical approach was favoured by one surgeon and was routinely used by the others when vesical diverticulectomy was performed. Transurethral resection was pierformed in II9 cases (19.7 70) and was used for small fibrous or previously confirmed carcinomatous glands. The junior surgical staff performed 49 Co of all operations, but All patients were admitted and investigated consultants performed all but 3 of the transhaematologically and radiologically before urethral resections. surgery and no emergency prostatectomies Prostatic tissue removed was examined were performed. histologically as a routine. Carcinoma was tPresent appointment: Senior Registrar, Department found in 52 patients (8.7 70), in 47 of whom of Surgery, Westminster Hospital, London. (7.8 7o) the diagnosis was unsuspected. Bladder The Editor would welcome any observations on this paper from readers. *Fellows and Members interested in submitting papers for consideration with a view to publication in this series should first write to the Editor.
460
R D Leach
papillomata were found in 7 patients (I.2%) none of whom had haematuria.
Complications Urinary tract infection was present in 72 patients (12%) before and 64 (10.7%) after operation, only 3 cases being recorded after transurethral resection. All responded to treatment with antibiotics. Gram-negative septicaemia occurred in 3 patients (0.5 Co), twice associated with urinary tract infections and once with a wound infection. There were no fatalities, although patient required peritoneal dialysis. Wound infections were uni
(3.9%) occurring
common, I9 open operations.
among
the 48I
Despite the advanced age of the patients only (I.8%) had chest infections. Ischaemic heart disease (myocardial infarction, congestive cardiac failure, and left ventricular failure) was seen in I 2 patients (2 7o), 4 of whom died. Pulmonary embolism was recorded in 5 patients (o.8 %), 3 of whom (o.s%) had clinical deep vein thrombosis; all i i
had had retropubic prostatectomies and had carcinoma. Two of these patients died. No routine prophylaxis against thrombosis was employed, although high-risk patients were given intravenous dextran. None of the patients who had pulmonary embolism had had i
prophylaxis.
Vesical calculi were removed at operation in 6 cases (i 7o). One patient reacted to an Haemorrhage requiring further surgery cystoscopy occurred in I3 patients (2.2 %7). iodine-based skin preparation and another reOne patient with severe mitral valve disease quired a cystoscopy to remove a suture from died during re-exploration for bleeding after the bladder which was causing repeated inretropubic prostatectomy. Routine vasectomy fections after a retropubic prostatectomy. The overall complication rate, including was employed by only one surgeon, who performed 99 operations with no epididymitis. urinary tract infections, was I43 (24%), delayWhen vasectomy was not routinely performed ing discharge from hospital by an average of the incidence of epididymitis was o.6%. Post- 9 days. operative retention of urine required further cystoscopy in 9 cases (3.2 7o). Incontinence Mortality lasting a year or more occurred in 4 patients The overall mortality in the immediate post(0.7%), 3 of whom had carcinoma of the operative period was 2.33% (14 deaths; see prostate. table). The mortality of open operation was Mortality of prostatectomy related to age, type of operation, pre-existing disease, and histology. or
i
Cause of death
Age
Presentation
Operation
Associated disease
(years)
During surgery for
54
Acute
TUR
67
69
Chronic Acute
RPP RPP
Myocardial infarct
72
Acute
RPP
Bronchopneumonia Cerebrovascular accident Cerebrovascular accident Bronchopneumonia Uraemia
74 76 78 79 82 84 84 86 89 89
Acute Acute Acute Chronic Chronic Acute Chronic Acute Acute Acute
TVP RPP RPP TVP TUR RPP RPP RPP TUR RPP
secondary haemorrhage Myocardial infarct Uraemia
Pulmonary embolism Cardiac failure Bronchopneumonia Cerebrovascular accident Pulmonary embolism
TUR
Mitral stenosis Diabetes. Chronic bronchitis and
emphysema. Hypertension. Ca. bladder. Ca. bronchus Ca. rectum
Chronic retention Chronic retention Dementia
Histology Benign Benign Benign Benign
Benign Benign Benign Benign Carcinoma Benign Carcinoma Benign Benign Carcinoma
transurethral resection; RPP = retropubic prostatectomy; TVP = transvesical prostatectomy
Prostatectomy at a district general hospital 2.5 To (I2 deaths) and of transurethral resection 1.7 To (2 deaths). The mean age of those who died was 77.3 years. Cardiorespiratory disease accounted for I2 (86%) of the 14 deaths, mortality from this cause being unaffected by the type of operation (transurethral resection 2.5 %, retropubic prostatectomy 2. I T, transvesical prostatectomy 3. %T). There was, however, a higher mortality rate among patients with carcinoma (5.7%) than among those with benign disease (2 %). Below the age of 70 mortality was i% and between 70 and 79 2.2%, but at 8o and above it was 7.4%, confirming previous reports that prostatic surgery has an increasing mortality with age. The mortality in patients presenting with acute retention was 2%, rising to 8.2% after the age of 8o. Presentation with chronic retention had an overall mortality of 4.9%, rising to i8.2 % after 8o years of age.
Discussion A specialist urological unit may perform up to 95 To of prostatectomies transurethrally' compared with 20% in the present series, which, as in Sachs and Marshall's series4, was due to the fact that general surgeons in training performed nearly half of the operations, using the technique with which they were more familiar. Mortality from prostatectomy depends on many factors, including age, mode of presentation, associated disease, type of operation, and experience of the surgeon. In the 6oo patients reviewed there was an overall mortality of 2.3 To. The reported overall mortality rates range from o.6To5 to 5.2To6. However, below the age of 70 years the mortality in the present series was I o and above 8o it was 7.4To. Watts7, reviewing 246 prostatectomies, gave a mortality of I3.3 '1 and Bergman et al8, in a series of I000 endoscopic resections, 8To for patients over 8o. Watts7 had 24.ITo and Sachs and Marshall4 2ITo of patients over 8o in their series, concluding that the age at which prostatectomy was being performed was increasing. In the present series only I3To of patients were over this age, but as the age of the population slowly increases symptoms will present later. Presentation with acute retention has been associated with a higher mortality, Salvaris9
46 I
reporting a 9. I % mortality under these circumstances and Melchior et al'0 a 2 .5 T mortality in a series of 2223 transurethral resections. The mortality in the present series was 2 % for patients who presented in this way, rising to 8.2 T% if the patient was over the age of 8o. This compares favourably with a mortality of 2o.8To recorded by Watts7 in patients with acute retention in the same age group. Cardiorespiratory disease is the major cause of death following prostatectomy and accounted for I 2 (86 To) of the deaths in the present series. Carcinoma of the prostate also has an increased operative mortality of between 5 and ioTo7'4, which is in agreement with the figure of 5.7To in this series. Eight of our patients who died had associated diseases (see table). Urinary tract infection after prostatectomy is an ever-present problem and is most commonly caused by coagulase-negative staphylococci and klebsiella enterobacter species which will often disappear after removal of the catheter and suitable antibiotic therapy". In the present series I0.7To of patients suffered significant postoperative urinary tract infection and 2 developed associated Gramnegative septicaemia. In the series reported by Watts4 8% developed urinary tract infection, but all patients had been given penicillin and streptomycin or ampicillin before the operation. The wound infection rate after open prostatectomy in the present series was 3.9To compared with Stearns's o.8To5 and Salvaris's ioTo9. Further surgery or cystoscopy was performed for haemorrhage in I3 cases (2.Io), which is considerably less than the rates reported by Cooper et al'2 (8.2 To) and Salvaris (8To). Routine vasectomy as a prophylactic procedure against epididymitis has almost been discarded with the advent of effective antibiotic therapy. However, Salvaris9 reports postoperative epididymitis in 3T% and Melchior et al° in 2.1I o of cases. In the present series epididymitis occurred in o.6To of cases and all resolved rapidly with antibiotics. Hedlund", using the fibrinogen uptake test, showed 45TC of patients in a control group undergoing prostatectomy to have a deep
462
R D Leach
venous thrombosis. He was able to reduce the rate of thrombosis to 27 Co with intravenous dextran and to 34% with subcutaneous heparin. Using no prophylactic agents, the rate of clinical deep vein thrombosis in the present series was o.5C, but in all probability the rate of thrombosis was considerably higher. Two of the 5 patients who suffered pulmonary embolism died (i with benign disease and i with carcinoma); it is worthy of note that both these patients were over 8o. Mean length of postoperative stay has become more important in the present economic climate. Stearns5, Lenko and Cieslinski14, and Salvaris9 give mean postoperative stays of 8.4, 9.9, and i8 days respectively. In the present series the mean postoperative stay was I 3.3 days. However, in benign uncomplicated cases this was reduced to 9.6 days and in uncomplicated patients with carcinoma to 11.4 days. Complications occurring in these groups of patients increased hospital stay by 9 and 20 days respectively. If the postoperative stay is to be reduced the complication rate must be reduced. Scrupulous surgical technique may reduce postoperative bleeding, but this is seen to be less common in the present series than in those previously reported. Preoperative treatment and care during urethral instrumentation are also essential to reduce infection rates. Further reduction of mortality and morbidity seems unlikely unless patients are below
the age of 8o and the incidence of preoperative cardiovascular disease can be reduced by education with regard to diet, smoking, and exercise. Even in specialist urological units the over-8o mortality from cardiorespiratory disease is little better than in this series7'4'8. I would like to thank the surgeons at Kingston upon Thames Hospital for permission to review their patients.
References I
2
3 4 5 6
7 8 9 io II
I2 I3
14
Blandy, J P (I97i) British Medical Journal, i, 3'. Blandy, J P (I978) British Journal of Hospital Medicine, 20, I 89. Millin, T (1948) Journal of Urology, 59, 267. Sachs, R, and Marshall, R V (I977) British Journal of Surgery, 64, 2IO. Stearns, D B (i96I) Journal of Urology, 85, 322. Allan, W R, and Coorey, G J (I966) British Journal of Urology, 38, I82. Watts, H G (I968) NewtJ Zealand Medical Journal, 67, 211. Bergman, T, Turner, R, Barnes, R W, and Hadley, H L (I955) Journal of Urology, 74, 533. Salvaris, M (I966) Medical Journal of Australia, I, 370. Melchior, J, Valk, W L, and Foret, J D (I974) Journal of Urology, 112, 634. Hills, N H, Bultitude, M I, and Eykin, S (1976) British Medical Journal, 2, 498. Cooper, J F, Ashamalia, G, and Cobbs, R (i966) Surgery, Gynecology and Obstetrics, I22, 277. Hedlund, P 0 (I973) Scandinavian Journal of Urology, 27, 87. Lenko, J, and Cieslinski, S (I965) British Journal of Urology, 37, 450.
ASPECTS OF TREATMENT*
Prostatectomy at a district general hospital R D Leach FRCS Surgical Registrar, Kingston upon Thames Hospital, Surreyt
Summary The mortality and morbidity in 6oo patients undergoing prostatectomy at a district general hospital are reviewed. Below the age of 70 years the operative mortality was I 7% compared with an overall mortality of 2.3%. Cardiorespiratory disease accounted for the majority of deaths. The increase of postoperative stay due to complications may be reduced by lowering the complication rate and, in the long term, reducing pre-existing cardiorespiratory disease. Introduction One man in i o may expect to undergo surgery for prostatic enlargement', but whether or not this should always be performed in urological units is still subject to controversy. Surgeons at district general hospitals have performed prostatectomy for many years even if the techniques employed by them have become less fashionable. Eighty per cent of prostatectomies in the United Kingdom are performed by open operation and often by surgeons with no specialist urological training2. This is confirmed by the experience at Kingston Hospital, which serves a population of 250 ooo and has no specialist urologist. Between 1970 and 1976 6oo prostatectomies were performed by 4 consultant surgeons and their junior staff. The results and complications of these operations are presented to affirm the position of prostatectomy at district general hospitals. Presentation and indications for surgery Prostatectomy was performed for acute retention in 350 cases (58.37), for chronic retention in 52 (8.7 %), and for prostatism in I98 (33 %).
Emergency presentation, however, accounted for 356 cases (597C); these patients were sent by family doctors, presented themselves at the Accident and Emergency Department, or were referred by other departments in the hospital. Acute retention of urine occurred in 30 patients (5 Co) following non-urological surgery and required prostatectomy during the same admission. The incidence of urinary outflow obstruction symptoms was as follows: poor stream 6 7%, frequency 66 %o, nocturia 6 Io, hesitancy 5270, dysuria I 970, and urgency i 6o . Haematuria occurred in 6o patients (i o o), in whom engorged prostatic veins were the only cause found. The mean age of the patients was 69.3 (3895) years. There were 441 (73.570) between 6o and 79 and 8i (I3.570) over 8o.
Surgical procedures
Each patient was carefully examined endoscopically and bimanually under anaesthesia. Open prostatectomy was performed in 48 I cases (80.270) and of these operations, 4I7 (69.570 of the total) were retropubic prostatectomies and 64 (I0.7 7o) transvesical. Retropubic prostatectomy was performed by Millin's method3, although there were minor variations in technique. The transvesical approach was favoured by one surgeon and was routinely used by the others when vesical diverticulectomy was performed. Transurethral resection was pierformed in II9 cases (19.7 70) and was used for small fibrous or previously confirmed carcinomatous glands. The junior surgical staff performed 49 Co of all operations, but All patients were admitted and investigated consultants performed all but 3 of the transhaematologically and radiologically before urethral resections. surgery and no emergency prostatectomies Prostatic tissue removed was examined were performed. histologically as a routine. Carcinoma was tPresent appointment: Senior Registrar, Department found in 52 patients (8.7 70), in 47 of whom of Surgery, Westminster Hospital, London. (7.8 7o) the diagnosis was unsuspected. Bladder The Editor would welcome any observations on this paper from readers. *Fellows and Members interested in submitting papers for consideration with a view to publication in this series should first write to the Editor.
460
R D Leach
papillomata were found in 7 patients (I.2%) none of whom had haematuria.
Complications Urinary tract infection was present in 72 patients (12%) before and 64 (10.7%) after operation, only 3 cases being recorded after transurethral resection. All responded to treatment with antibiotics. Gram-negative septicaemia occurred in 3 patients (0.5 Co), twice associated with urinary tract infections and once with a wound infection. There were no fatalities, although patient required peritoneal dialysis. Wound infections were uni
(3.9%) occurring
common, I9 open operations.
among
the 48I
Despite the advanced age of the patients only (I.8%) had chest infections. Ischaemic heart disease (myocardial infarction, congestive cardiac failure, and left ventricular failure) was seen in I 2 patients (2 7o), 4 of whom died. Pulmonary embolism was recorded in 5 patients (o.8 %), 3 of whom (o.s%) had clinical deep vein thrombosis; all i i
had had retropubic prostatectomies and had carcinoma. Two of these patients died. No routine prophylaxis against thrombosis was employed, although high-risk patients were given intravenous dextran. None of the patients who had pulmonary embolism had had i
prophylaxis.
Vesical calculi were removed at operation in 6 cases (i 7o). One patient reacted to an Haemorrhage requiring further surgery cystoscopy occurred in I3 patients (2.2 %7). iodine-based skin preparation and another reOne patient with severe mitral valve disease quired a cystoscopy to remove a suture from died during re-exploration for bleeding after the bladder which was causing repeated inretropubic prostatectomy. Routine vasectomy fections after a retropubic prostatectomy. The overall complication rate, including was employed by only one surgeon, who performed 99 operations with no epididymitis. urinary tract infections, was I43 (24%), delayWhen vasectomy was not routinely performed ing discharge from hospital by an average of the incidence of epididymitis was o.6%. Post- 9 days. operative retention of urine required further cystoscopy in 9 cases (3.2 7o). Incontinence Mortality lasting a year or more occurred in 4 patients The overall mortality in the immediate post(0.7%), 3 of whom had carcinoma of the operative period was 2.33% (14 deaths; see prostate. table). The mortality of open operation was Mortality of prostatectomy related to age, type of operation, pre-existing disease, and histology. or
i
Cause of death
Age
Presentation
Operation
Associated disease
(years)
During surgery for
54
Acute
TUR
67
69
Chronic Acute
RPP RPP
Myocardial infarct
72
Acute
RPP
Bronchopneumonia Cerebrovascular accident Cerebrovascular accident Bronchopneumonia Uraemia
74 76 78 79 82 84 84 86 89 89
Acute Acute Acute Chronic Chronic Acute Chronic Acute Acute Acute
TVP RPP RPP TVP TUR RPP RPP RPP TUR RPP
secondary haemorrhage Myocardial infarct Uraemia
Pulmonary embolism Cardiac failure Bronchopneumonia Cerebrovascular accident Pulmonary embolism
TUR
Mitral stenosis Diabetes. Chronic bronchitis and
emphysema. Hypertension. Ca. bladder. Ca. bronchus Ca. rectum
Chronic retention Chronic retention Dementia
Histology Benign Benign Benign Benign
Benign Benign Benign Benign Carcinoma Benign Carcinoma Benign Benign Carcinoma
transurethral resection; RPP = retropubic prostatectomy; TVP = transvesical prostatectomy
Prostatectomy at a district general hospital 2.5 To (I2 deaths) and of transurethral resection 1.7 To (2 deaths). The mean age of those who died was 77.3 years. Cardiorespiratory disease accounted for I2 (86%) of the 14 deaths, mortality from this cause being unaffected by the type of operation (transurethral resection 2.5 %, retropubic prostatectomy 2. I T, transvesical prostatectomy 3. %T). There was, however, a higher mortality rate among patients with carcinoma (5.7%) than among those with benign disease (2 %). Below the age of 70 mortality was i% and between 70 and 79 2.2%, but at 8o and above it was 7.4%, confirming previous reports that prostatic surgery has an increasing mortality with age. The mortality in patients presenting with acute retention was 2%, rising to 8.2% after the age of 8o. Presentation with chronic retention had an overall mortality of 4.9%, rising to i8.2 % after 8o years of age.
Discussion A specialist urological unit may perform up to 95 To of prostatectomies transurethrally' compared with 20% in the present series, which, as in Sachs and Marshall's series4, was due to the fact that general surgeons in training performed nearly half of the operations, using the technique with which they were more familiar. Mortality from prostatectomy depends on many factors, including age, mode of presentation, associated disease, type of operation, and experience of the surgeon. In the 6oo patients reviewed there was an overall mortality of 2.3 To. The reported overall mortality rates range from o.6To5 to 5.2To6. However, below the age of 70 years the mortality in the present series was I o and above 8o it was 7.4To. Watts7, reviewing 246 prostatectomies, gave a mortality of I3.3 '1 and Bergman et al8, in a series of I000 endoscopic resections, 8To for patients over 8o. Watts7 had 24.ITo and Sachs and Marshall4 2ITo of patients over 8o in their series, concluding that the age at which prostatectomy was being performed was increasing. In the present series only I3To of patients were over this age, but as the age of the population slowly increases symptoms will present later. Presentation with acute retention has been associated with a higher mortality, Salvaris9
46 I
reporting a 9. I % mortality under these circumstances and Melchior et al'0 a 2 .5 T mortality in a series of 2223 transurethral resections. The mortality in the present series was 2 % for patients who presented in this way, rising to 8.2 T% if the patient was over the age of 8o. This compares favourably with a mortality of 2o.8To recorded by Watts7 in patients with acute retention in the same age group. Cardiorespiratory disease is the major cause of death following prostatectomy and accounted for I 2 (86 To) of the deaths in the present series. Carcinoma of the prostate also has an increased operative mortality of between 5 and ioTo7'4, which is in agreement with the figure of 5.7To in this series. Eight of our patients who died had associated diseases (see table). Urinary tract infection after prostatectomy is an ever-present problem and is most commonly caused by coagulase-negative staphylococci and klebsiella enterobacter species which will often disappear after removal of the catheter and suitable antibiotic therapy". In the present series I0.7To of patients suffered significant postoperative urinary tract infection and 2 developed associated Gramnegative septicaemia. In the series reported by Watts4 8% developed urinary tract infection, but all patients had been given penicillin and streptomycin or ampicillin before the operation. The wound infection rate after open prostatectomy in the present series was 3.9To compared with Stearns's o.8To5 and Salvaris's ioTo9. Further surgery or cystoscopy was performed for haemorrhage in I3 cases (2.Io), which is considerably less than the rates reported by Cooper et al'2 (8.2 To) and Salvaris (8To). Routine vasectomy as a prophylactic procedure against epididymitis has almost been discarded with the advent of effective antibiotic therapy. However, Salvaris9 reports postoperative epididymitis in 3T% and Melchior et al° in 2.1I o of cases. In the present series epididymitis occurred in o.6To of cases and all resolved rapidly with antibiotics. Hedlund", using the fibrinogen uptake test, showed 45TC of patients in a control group undergoing prostatectomy to have a deep
462
R D Leach
venous thrombosis. He was able to reduce the rate of thrombosis to 27 Co with intravenous dextran and to 34% with subcutaneous heparin. Using no prophylactic agents, the rate of clinical deep vein thrombosis in the present series was o.5C, but in all probability the rate of thrombosis was considerably higher. Two of the 5 patients who suffered pulmonary embolism died (i with benign disease and i with carcinoma); it is worthy of note that both these patients were over 8o. Mean length of postoperative stay has become more important in the present economic climate. Stearns5, Lenko and Cieslinski14, and Salvaris9 give mean postoperative stays of 8.4, 9.9, and i8 days respectively. In the present series the mean postoperative stay was I 3.3 days. However, in benign uncomplicated cases this was reduced to 9.6 days and in uncomplicated patients with carcinoma to 11.4 days. Complications occurring in these groups of patients increased hospital stay by 9 and 20 days respectively. If the postoperative stay is to be reduced the complication rate must be reduced. Scrupulous surgical technique may reduce postoperative bleeding, but this is seen to be less common in the present series than in those previously reported. Preoperative treatment and care during urethral instrumentation are also essential to reduce infection rates. Further reduction of mortality and morbidity seems unlikely unless patients are below
the age of 8o and the incidence of preoperative cardiovascular disease can be reduced by education with regard to diet, smoking, and exercise. Even in specialist urological units the over-8o mortality from cardiorespiratory disease is little better than in this series7'4'8. I would like to thank the surgeons at Kingston upon Thames Hospital for permission to review their patients.
References I
2
3 4 5 6
7 8 9 io II
I2 I3
14
Blandy, J P (I97i) British Medical Journal, i, 3'. Blandy, J P (I978) British Journal of Hospital Medicine, 20, I 89. Millin, T (1948) Journal of Urology, 59, 267. Sachs, R, and Marshall, R V (I977) British Journal of Surgery, 64, 2IO. Stearns, D B (i96I) Journal of Urology, 85, 322. Allan, W R, and Coorey, G J (I966) British Journal of Urology, 38, I82. Watts, H G (I968) NewtJ Zealand Medical Journal, 67, 211. Bergman, T, Turner, R, Barnes, R W, and Hadley, H L (I955) Journal of Urology, 74, 533. Salvaris, M (I966) Medical Journal of Australia, I, 370. Melchior, J, Valk, W L, and Foret, J D (I974) Journal of Urology, 112, 634. Hills, N H, Bultitude, M I, and Eykin, S (1976) British Medical Journal, 2, 498. Cooper, J F, Ashamalia, G, and Cobbs, R (i966) Surgery, Gynecology and Obstetrics, I22, 277. Hedlund, P 0 (I973) Scandinavian Journal of Urology, 27, 87. Lenko, J, and Cieslinski, S (I965) British Journal of Urology, 37, 450.
