Comment 4. Case 26 had a cervical spine process fracture which is AIS 2 and flail chest which is AIS 4, hence this patient's ISS is 24 but in error this was printed as 25, again this does not influence the probability of survival or outcome for this patient.
The use of level of consciousness has a definite role in AIS 80, in fact the AIS 80 suggests that in cases where information on both anatomical lesion and level of consciousness is available the higher of the two AIS codes should be assigned to the
injury. The study was based on experience of one General District Hospital and the cases were accurately reported. In this study only one patient's score was incorrect, Case 13, where the outcome may have been affected and hence we would disagree that there are any fundamental flaws in the study. We think Mr Cross and his colleagues are working out the injury severity score from AIS 90 which has only recently been published and hence the confusion. As mentioned earlier, this study was based on AIS 80, this may explain some of their concerns regarding the study. We are informed from the MTOS (UK) Office that both they and MTOS (USA) do not recommend the use of AIS 90 for a study like this, ie TRISS methodology, at present, as AIS 90 requires different coefficients to work out the probability of survival, and we hope that Mr Cross and his colleagues at HEMS are not using AIS 90 for analysis of their results. NADEEM NAYEEM FRCS Senior Registrar in Accident and Emergency Guy's Hospital London MOHINDRA B KOTECHA FRCS Consultant in Accident & Emergency Medicine Luton and Dunstable Hospital Luton
Laparoscopic cholecystectomy We welcome the comments of Lord McColl on laparoscopic cholecystectomy (Annals, July 1992, vol 74, p231), pointing out that the risk of accidental bowel perforation can be greatly reduced by the 'open' technique of laparoscopy in which the abdomen is entered under direct vision (1). He failed to mention, however, that the open technique should also completely eliminate the most feared complication of laparoscopy, that is major vessel injury (2). This catastrophic event is estimated to occur in between 3 and 10 per 10 000 closed laparoscopic procedures (3-5), but these retrospective surveys may underestimate the incidence. We are aware of major vessel injuries occurring during diagnostic laparoscopy and laparoscopic cholecystectomy using both reusable and disposable trocars with a safety shield. The open technique also avoids the risk of subcutaneous, omental, or mesenteric emphysema from insufflation through a misplaced Veress needle. Unfortunately, few surgeons choose to adopt the open technique of laparoscopy. The trocar can be placed anywhere in the abdomen and does not add time to the procedure once the surgeon has become familiar with the technique. The use of a Hasson's laparoscopic cannula, with its olive-shaped sleeve on the shaft of the cannula, greatly simplifies the technique. Moreover, reusable trocars can be safely used in open laparoscopy, resulting in a significant saving for those who use disposable trocars. ANDREW J MCMAHON FRCS Surgical Research Fellow PATRICK J O'DWYER MCh FRCS Senior Lecturer in Surgery
439
JOHN N BAXTER MD FRACS Senior Lecturer in Surgery
University Department of Surgery Western Infirmary, Glasgow References I Penfield AJ. How to prevent complications of open laparoscopy. J Reprod Med 1985;30:660. 2 Baadsgaard SE, Billek S, Egeblad K. Major vascular injury during gynecologic laparoscopy. Acta Obstet Gynecol Scand 1989;68:283-5. 3 Mintz M. Risks and prophylaxis in laparoscopy: a survey of 100,000 cases. J Reprod Med 1977;18:269-72. 4 Peterson H, Greenspan J, Ory H. Death following puncture of the aorta during laparoscopic sterilization. Obstet Gynecol 1981;59: 133-4. S Riedel HH, Willenbrock-Lehnmann E, Mecke H, Semm K. The frequency of distribution of various pelviscopic (laparoscopic) operations, including complication rates-statistics of the Federal Republic of Germany in the years 1983-1985. Zentralbl Gynakol 1989;11l:78-91.
Can cholangiography be safely abandoned in laparoscopic cholecystectomy? Laparoscopic operative cholangiography: a simple, successful, cost-effective method The first definite warning that laparoscopic cholecystectomy may lead to an increase in damage to the major bile ducts came from a group of American Surgeons (1) who found a damage rate of 0.5% in just over 1500 patients. This compares with a rate of 0.15% found in open cholecystectomy (2). At a recent Congress in Bordeaux (3), the incidence of major duct injury in several large series was reported; in just over 8000 patients in Baltimore it was 0.22%, the Swiss Association found in just over 1000 patients and a Belgium Group in just over 3000 patients a rate of 0.5%; in a series from Japan of nearly 3000 patients the rate was 0.9% and in a series of 1100 patients from Singapore the rate was 1.6%. There were reports from South Carolina and the Lahey Clinic describing 26 patients who had suffered major duct injury during laparoscopic cholecystectomy. Only one of these patients had had operative cholangiography which led to the immediate recognition of the injury; approximately 50% of the remaining patients had a delayed diagnosis. I was therefore interested in your recent articles (Annals, July 1992 vol 74, p248, p252) which used one reference in each case case to suggest that operative cholangiography did or did not decrease the risk of main duct damage. The authors of those papers know that there is not enough information from the literature to give us the answer to this question. In the absence of that answer, the rule in order to avoid damage is to know at operation the precise position of the bile ducts, particularly the confluence of the common hepatic duct, the cystic duct and the common bile duct. The confluence can be identified by direct vision as in open surgery, endoscopic vision which is only possible in a small minority of cases, or by X-ray vision (peroperative cholangiography via the cystic duct or gallbladder). If the confluence cannot be identified by the latter two methods then conversion to an open operation should follow. I am concerned about the approach of tracing the cystic duct from the gallbladder and not visualising the confluence. This approach can be difficult technically because of bleeding problems; more importantly, the cystic duct may be absent and the gallbladder open directly into the right hepatic or common
The use of level of consciousness has a definite role in AIS 80, in fact the AIS 80 suggests that in cases where information on both anatomical lesion and level of consciousness is available the higher of the two AIS codes should be assigned to the
injury. The study was based on experience of one General District Hospital and the cases were accurately reported. In this study only one patient's score was incorrect, Case 13, where the outcome may have been affected and hence we would disagree that there are any fundamental flaws in the study. We think Mr Cross and his colleagues are working out the injury severity score from AIS 90 which has only recently been published and hence the confusion. As mentioned earlier, this study was based on AIS 80, this may explain some of their concerns regarding the study. We are informed from the MTOS (UK) Office that both they and MTOS (USA) do not recommend the use of AIS 90 for a study like this, ie TRISS methodology, at present, as AIS 90 requires different coefficients to work out the probability of survival, and we hope that Mr Cross and his colleagues at HEMS are not using AIS 90 for analysis of their results. NADEEM NAYEEM FRCS Senior Registrar in Accident and Emergency Guy's Hospital London MOHINDRA B KOTECHA FRCS Consultant in Accident & Emergency Medicine Luton and Dunstable Hospital Luton
Laparoscopic cholecystectomy We welcome the comments of Lord McColl on laparoscopic cholecystectomy (Annals, July 1992, vol 74, p231), pointing out that the risk of accidental bowel perforation can be greatly reduced by the 'open' technique of laparoscopy in which the abdomen is entered under direct vision (1). He failed to mention, however, that the open technique should also completely eliminate the most feared complication of laparoscopy, that is major vessel injury (2). This catastrophic event is estimated to occur in between 3 and 10 per 10 000 closed laparoscopic procedures (3-5), but these retrospective surveys may underestimate the incidence. We are aware of major vessel injuries occurring during diagnostic laparoscopy and laparoscopic cholecystectomy using both reusable and disposable trocars with a safety shield. The open technique also avoids the risk of subcutaneous, omental, or mesenteric emphysema from insufflation through a misplaced Veress needle. Unfortunately, few surgeons choose to adopt the open technique of laparoscopy. The trocar can be placed anywhere in the abdomen and does not add time to the procedure once the surgeon has become familiar with the technique. The use of a Hasson's laparoscopic cannula, with its olive-shaped sleeve on the shaft of the cannula, greatly simplifies the technique. Moreover, reusable trocars can be safely used in open laparoscopy, resulting in a significant saving for those who use disposable trocars. ANDREW J MCMAHON FRCS Surgical Research Fellow PATRICK J O'DWYER MCh FRCS Senior Lecturer in Surgery
439
JOHN N BAXTER MD FRACS Senior Lecturer in Surgery
University Department of Surgery Western Infirmary, Glasgow References I Penfield AJ. How to prevent complications of open laparoscopy. J Reprod Med 1985;30:660. 2 Baadsgaard SE, Billek S, Egeblad K. Major vascular injury during gynecologic laparoscopy. Acta Obstet Gynecol Scand 1989;68:283-5. 3 Mintz M. Risks and prophylaxis in laparoscopy: a survey of 100,000 cases. J Reprod Med 1977;18:269-72. 4 Peterson H, Greenspan J, Ory H. Death following puncture of the aorta during laparoscopic sterilization. Obstet Gynecol 1981;59: 133-4. S Riedel HH, Willenbrock-Lehnmann E, Mecke H, Semm K. The frequency of distribution of various pelviscopic (laparoscopic) operations, including complication rates-statistics of the Federal Republic of Germany in the years 1983-1985. Zentralbl Gynakol 1989;11l:78-91.
Can cholangiography be safely abandoned in laparoscopic cholecystectomy? Laparoscopic operative cholangiography: a simple, successful, cost-effective method The first definite warning that laparoscopic cholecystectomy may lead to an increase in damage to the major bile ducts came from a group of American Surgeons (1) who found a damage rate of 0.5% in just over 1500 patients. This compares with a rate of 0.15% found in open cholecystectomy (2). At a recent Congress in Bordeaux (3), the incidence of major duct injury in several large series was reported; in just over 8000 patients in Baltimore it was 0.22%, the Swiss Association found in just over 1000 patients and a Belgium Group in just over 3000 patients a rate of 0.5%; in a series from Japan of nearly 3000 patients the rate was 0.9% and in a series of 1100 patients from Singapore the rate was 1.6%. There were reports from South Carolina and the Lahey Clinic describing 26 patients who had suffered major duct injury during laparoscopic cholecystectomy. Only one of these patients had had operative cholangiography which led to the immediate recognition of the injury; approximately 50% of the remaining patients had a delayed diagnosis. I was therefore interested in your recent articles (Annals, July 1992 vol 74, p248, p252) which used one reference in each case case to suggest that operative cholangiography did or did not decrease the risk of main duct damage. The authors of those papers know that there is not enough information from the literature to give us the answer to this question. In the absence of that answer, the rule in order to avoid damage is to know at operation the precise position of the bile ducts, particularly the confluence of the common hepatic duct, the cystic duct and the common bile duct. The confluence can be identified by direct vision as in open surgery, endoscopic vision which is only possible in a small minority of cases, or by X-ray vision (peroperative cholangiography via the cystic duct or gallbladder). If the confluence cannot be identified by the latter two methods then conversion to an open operation should follow. I am concerned about the approach of tracing the cystic duct from the gallbladder and not visualising the confluence. This approach can be difficult technically because of bleeding problems; more importantly, the cystic duct may be absent and the gallbladder open directly into the right hepatic or common
