Comment doubt whether a trial of this nature would have been mounted. It is of course impossible for such a specialist or service to be responsible for every minor hand injury, but a policy based on such expert knowledge could be evolved. C R RAYNER MS FRCS Consultant Plastic Surgeon Aberdeen Royal Infirmary Foresterhill, Aberdeen
Robson and Bloom report a controlled trial of digital block versus local infiltration of local anaesthetic for suturing digital lacerations (Annals, November 1990, vol 72, p360). Their conclusion that local infiltration within the finger is unsatisfactory is so self-evident that it seems surprising that they were able to complete their study. However, it is unfortunate that they compared this with a block of the digital nerves within the finger since this is also painful, and their paper does not give any information about the levels of pain with the two methods, only the statistical difference between the two, and this information should be provided. If the digital nerve block is carried out by passing a 23G needle from the dorsum of the web in a proximal direction into the loose palmar space it is possible to inject the local anaesthetic with virtually no pain provided it is done slowly, and this has the advantage of avoiding any distention of the finger at all. The block is, of course, performed on both sides of the affected digit and dorsal local anaesthetic is also required at the same level. DAVID M EVANS FRCS Consultant Plastic Surgeon Wexham Park Hospital Slough, Berks
A retractor for cholecystectomy We were interested to read about the self-retaining retractor being used in Burton-on-Trent for cholecystectomies (Annals, November 1990, vol 72, p362). We agree wholeheartedly that the use of such a retractor is of great benefit in this and other procedures on the biliary tract. We would like to point out, however, that a similar retractor is already commercially available. The Bennett-Jones retractor (Thackeray Ltd) was described in 1955 (1) and has been more recently assessed (2). One of us (JGT) has been using this instrument for 18 years, whereas the other is a more recent convert. The additional benefit of the Bennett-Jones retractor is that there is a third optional blade which retracts medially. The use of this instrument allows a surgeon to operate without a trained or experienced assistant, while maintaining an excellent view of the operative field. We would recommend that anyone working in this situation should give the retractor a trial. ROBERT M KIRBY MD FRCS Senior Registrar in Surgery JOHN G TEMPLE ChM FRCS Consultant Surgeon Queen Elizabeth Hospital
Birfiingham References I Bennett-Jones MJ. A retractor for cholecystectomy. Lancet 1955;2:854. 2 Temple JG. The Bennett-Jones retractor. J R Coll Surg Edinb 1976;21:237-8.
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Factors influencing peritoneal catheter survival in continuous ambulatory peritoneal dialysis The technical problems that complicate the insertion of CAPD catheters are well known to clinicians with an interest in dialysis access work. The article by Nicholson et al. (Annals, November 1990, vol 72, p368) identifying factors that influence catheter survival is therefore most welcome. However, the discussion of the value of peritoneoscopic placement of catheters was misleading. We have recently reviewed our experience with this technique and expect to publish full results shortly. One hundred consecutively placed catheters had a catheter survival of 0.85 at 18 months as calculated by Kaplan Meier analysis. There were only five early catheter failures which included one perforated viscus. As a consequence of the excellent results achieved using this technique, endoscopic placement of CAPD catheters is now the method of choice in our centre. The procedure is well tolerated under local anaesthetic and, because of the low initial leakage rate, immediate dialysis can be instituted in 93% of patients if necessary. General anaesthetic, minilaparotomy, omentectomy and open placement of Tenckhoff catheters in unfit, high-risk patients is therefore an uncommon procedure in our unit. A S ADAMSON FRCS Research Registrar in Urology St Mary's Hospital London
Antiseptic toxicity to breast carcinoma in tissue culture: an adjuvant to conservation therapy? I was interested to read the article by Lucarotti et al. (Annals, November 1990, vol 72, p388) on adjuvant therapy in breast carcinoma treated by local excision. They demonstrate that both hydrogen peroxide and Eusol show preferential cytocidal action to the breast tumour cell line MCF7. However, I must add a note of caution before these findings are extended to clinical trials. The use of hydrogen peroxide in closed cavities, such as the excision cavity, may result in fatal oxygen embolus. Catalysed by the blood enzyme catalase, 6% hydrogen peroxide breaks down to produce 20 volumes of oxygen for every volume of peroxide. In closed areas where open vessels may exist there is a high risk of embolus from the released oxygen (1), and fatalities have been recorded. C J E WATSON MA FRCS Honorary Registrar Addenbrooke's Hospital Cambridge
Reference 1 Sleigh JW, Linter SPK. Hazards of hydrogen peroxide. Br MedJ_ 1985;291:1706.
Outpatient carpal tunnel decompression without toumiquet: a simple local anaesthetic technique I have read with interest the above paper (Annals, November 1990, vol 72, p408). We have for some years now in the Stockport district carried out decompression of the median nerve under local anaesthetic. We do not use adrenaline but use a tourniquet and find the incidence of tourniquet discomfort as being extremely low and patients are extremely happy to undergo this procedure knowing it does not involve all the problems of a general anaesthetic. I cannot see any need to
Robson and Bloom report a controlled trial of digital block versus local infiltration of local anaesthetic for suturing digital lacerations (Annals, November 1990, vol 72, p360). Their conclusion that local infiltration within the finger is unsatisfactory is so self-evident that it seems surprising that they were able to complete their study. However, it is unfortunate that they compared this with a block of the digital nerves within the finger since this is also painful, and their paper does not give any information about the levels of pain with the two methods, only the statistical difference between the two, and this information should be provided. If the digital nerve block is carried out by passing a 23G needle from the dorsum of the web in a proximal direction into the loose palmar space it is possible to inject the local anaesthetic with virtually no pain provided it is done slowly, and this has the advantage of avoiding any distention of the finger at all. The block is, of course, performed on both sides of the affected digit and dorsal local anaesthetic is also required at the same level. DAVID M EVANS FRCS Consultant Plastic Surgeon Wexham Park Hospital Slough, Berks
A retractor for cholecystectomy We were interested to read about the self-retaining retractor being used in Burton-on-Trent for cholecystectomies (Annals, November 1990, vol 72, p362). We agree wholeheartedly that the use of such a retractor is of great benefit in this and other procedures on the biliary tract. We would like to point out, however, that a similar retractor is already commercially available. The Bennett-Jones retractor (Thackeray Ltd) was described in 1955 (1) and has been more recently assessed (2). One of us (JGT) has been using this instrument for 18 years, whereas the other is a more recent convert. The additional benefit of the Bennett-Jones retractor is that there is a third optional blade which retracts medially. The use of this instrument allows a surgeon to operate without a trained or experienced assistant, while maintaining an excellent view of the operative field. We would recommend that anyone working in this situation should give the retractor a trial. ROBERT M KIRBY MD FRCS Senior Registrar in Surgery JOHN G TEMPLE ChM FRCS Consultant Surgeon Queen Elizabeth Hospital
Birfiingham References I Bennett-Jones MJ. A retractor for cholecystectomy. Lancet 1955;2:854. 2 Temple JG. The Bennett-Jones retractor. J R Coll Surg Edinb 1976;21:237-8.
131
Factors influencing peritoneal catheter survival in continuous ambulatory peritoneal dialysis The technical problems that complicate the insertion of CAPD catheters are well known to clinicians with an interest in dialysis access work. The article by Nicholson et al. (Annals, November 1990, vol 72, p368) identifying factors that influence catheter survival is therefore most welcome. However, the discussion of the value of peritoneoscopic placement of catheters was misleading. We have recently reviewed our experience with this technique and expect to publish full results shortly. One hundred consecutively placed catheters had a catheter survival of 0.85 at 18 months as calculated by Kaplan Meier analysis. There were only five early catheter failures which included one perforated viscus. As a consequence of the excellent results achieved using this technique, endoscopic placement of CAPD catheters is now the method of choice in our centre. The procedure is well tolerated under local anaesthetic and, because of the low initial leakage rate, immediate dialysis can be instituted in 93% of patients if necessary. General anaesthetic, minilaparotomy, omentectomy and open placement of Tenckhoff catheters in unfit, high-risk patients is therefore an uncommon procedure in our unit. A S ADAMSON FRCS Research Registrar in Urology St Mary's Hospital London
Antiseptic toxicity to breast carcinoma in tissue culture: an adjuvant to conservation therapy? I was interested to read the article by Lucarotti et al. (Annals, November 1990, vol 72, p388) on adjuvant therapy in breast carcinoma treated by local excision. They demonstrate that both hydrogen peroxide and Eusol show preferential cytocidal action to the breast tumour cell line MCF7. However, I must add a note of caution before these findings are extended to clinical trials. The use of hydrogen peroxide in closed cavities, such as the excision cavity, may result in fatal oxygen embolus. Catalysed by the blood enzyme catalase, 6% hydrogen peroxide breaks down to produce 20 volumes of oxygen for every volume of peroxide. In closed areas where open vessels may exist there is a high risk of embolus from the released oxygen (1), and fatalities have been recorded. C J E WATSON MA FRCS Honorary Registrar Addenbrooke's Hospital Cambridge
Reference 1 Sleigh JW, Linter SPK. Hazards of hydrogen peroxide. Br MedJ_ 1985;291:1706.
Outpatient carpal tunnel decompression without toumiquet: a simple local anaesthetic technique I have read with interest the above paper (Annals, November 1990, vol 72, p408). We have for some years now in the Stockport district carried out decompression of the median nerve under local anaesthetic. We do not use adrenaline but use a tourniquet and find the incidence of tourniquet discomfort as being extremely low and patients are extremely happy to undergo this procedure knowing it does not involve all the problems of a general anaesthetic. I cannot see any need to
