C. K. Kum

Probability of adverse events that have not yet occurred: a statistical reminder.

The probability of adverse and undesirable events during and after operations that have not yet occurred in a finite number of patients (n) can be estimated with Hanleys simple formula, which gives the upper limit of the 95% confidence interval of the probability of such an event: upper limit of 95% confidence interval = maximum risk = 3/n (for n > 30). Doctors and surgeons should keep this simple rule in mind when complication rates of zero are reported in the literature and when they have not (yet) experienced a disastrous complication in a procedure.

Laparoscopic Cholecystectomy for Acute Cholecystitis: Is It Really Safe?

Abstract. The prospectively collected data from 530 cholecystectomies performed in a university clinic from October 1989 to March 1991 were analyzed after 1 to 3 years of follow-up. The aim of this study was to compare the results of laparoscopic cholecystectomy (LC) for acute cholecystitis with that for routine symptomatic gallbladders. The preoperative, intraoperative, and postoperative parameters of 424 routine (noninflamed) LCs and 54 LCs for acutely inflamed gallbladders were compared under the “intention to treat” principle. Operating time was longer in the inflamed group (median 97 minutes versus 75 minutes;p < 0.0001). Significantly more adhesions (20% versus 8%), more blood loss (48% versus 19%), a higher incidence of bile spillage (28% versus 12%), and lost stones (19% versus 8%) were encountered in patients with acute cholecystitis. Common bile duct (CBD) injuries were also more frequent in that group (5.5% versus 0.2%;p = 0.005). The rate of conversion to open surgery was higher than with routine LCs (13% versus 4%). There were two deaths in the routine LC group and none in the acutely inflamed group. There was no difference in postoperative pain intensity or postoperative fatigue according to visual analog scale measurements. Patients with acute cholecystitis stayed only 1 day longer (median 4 days versus 3 days) in hospital. The quality of life scores indicate return to almost normal values by the 14th postoperative day. Long-term follow-up (1–3 years) did not reveal any delayed clinical adverse effects. In summary, LC for inflamed gallbladders has a higher conversion rate than LC for routine symptomatic gallbladders. If successfully performed, it has definite benefit for the patient in terms of better postoperative recovery. The trade-off is that the risk of CBD injury is significantly higher.

Comparison between laparoscopic and conventional omental patch repair for perforated duodenal ulcer

AbstractBackground: The aim of the study is to evaluate the safety and efficacy of laparoscopic omental patch repair. Method: This is a retrospective review of 53 consecutive patients with omental patch repair for perforated duodenal ulcer; 38 underwent conventional open approach and 15 underwent laparoscopic patch repair. The only selection criterion was availability of expertise for laparoscopic repair on the day of admission. By chance, the open group had poorer ASA scores. There were four deaths and five postoperative complications in the open group. Results: Laparoscopic repair was successful in 14 cases with one postoperative complication. Operative time was longer in the laparoscopic group (80 vs 65 min in open group, p= 0.02). Patients required less postoperative analgesics in the laparoscopic group (median amount of pethidine was 75 mg vs 175 mg in the open group, p= 0.03). There was no statistically significant difference in terms of hospital stay and return to normal activities between the two procedures. Follow-up Visick scores were comparable in both groups. Conclusions: Laparoscopic omental patch repair offers a safe alternative to the conventional method and causes less postoperative pain.

Laparoscopic appendectomy for perforated appendicitis

Although laparoscopic appendectomy for uncomplicated appendicitis is feasible and safe, its application to perforated appendicitis is uncertain. A retrospective study of all patients with perforated appendicitis from 1992 to 1999 in a university hospital was performed. A series of 231 patients were diagnosed as having perforated appendicitis. Of these patients, 85 underwent laparoscopy (LA), among whom 40 (47%) required conversion to an open procedure. An open appendectomy (OA) was performed in 146 patients. The operating time was similar for the two groups. Return of fluid and solid diet intake were faster in LA than OA patients (p<0.01). Postoperative infections including wound infections and abdominal abscesses occurred in 14% of patients in the laparoscopy group and in 26% of those with OA (p<0.05). The surgeon’s experience correlated with the conversion rate. Laparoscopic appendectomy is associated with a high conversion rate for perforated appendicitis. If successful, it offers patients faster recovery and less risk of infectious complications.RésuméAlors que l’appendicectomie par laparoscopic pour appendicite non compliquée est faisable et sûre, son rôle dans l’appendicite perforée reste incertain. On a analysé rétrospectivement les résultats chez tous les patients traités pour appendicite perforée entre 1992 et 1999 dans un service de chirurgie d’un hôptial universitaire: 231 patients ont ainsi été inclus dans cette étude. Quatre-vingt-cinq patients ont eu une laparoscopic (LA): 40 patients (47%) ont nécessité une conversion à la voie tradtionnelle. Une appendicectomie par voie traditionnelle (OA) a été réalisée chez 146 patients. La durée de l’intervention était similaire entre les deux groupes. La reprise d’alimentation orale et solide a été plus rapide dans le groupe LA par rapport au groupe OA (p<0.01). On a noté des complications infectieuses, y compris des infections pariétales et des abcès intra-abdominaux chez 14% dans le groupe L, comparé à 26% pour le groupe O (p<0.05). L’expérience du chirurgien a été corrélée directement avec le taux de conversion. L’appendicectomie laparoscopique est associée à un taux élevé de conversion en raison de l’appendicite perforée. En cas de succès, la récupération est plus rapide et il y a moins de risque de complications infectieuses.ResumenMientras que la apendicectomía laparoscópica es posible y segura en las apendicitis no complicadas, el papel de la laparoscópia en el tratamiento de la apendicitis perforada está muy controvertido. En un hospital universitario se efectuó un estudio retrospectivo de todos aquellos casos de apendicitis perforada, intervenidos entre 1992 y 1999. 231 pacientes ftieron diagnosticados de perforación apendicular. 85 fueron tratados por laparoscópia (LA) pero 40 (47%) requirieron reconversión a cirugía abierta. Con apendicectomía abierta (OA) se trataron 146 enfermos. La duración de la operación fue similar en ambos grupos. La iniciación de la ingesta de líquidos y sólidos fue más precoz en el grupo LA que en el OA (p<0.01). Infección postoperatoria que comprende tanto la de la herida como abscesos abdominales, se constató en el 14% de los pacientes del grupo LA y en el 26% de los del grupo OA (p<0.05). La experiencia del cirujano se correlacionó directamente con la tasa de reconversión. Ésta es mucho más frecuente en el tratamiento laparoscópico de las apendicitis perforadas. Si la apendicectomía laparoscópica puede realizarse satisfactoriamente el paciente se recuperará con más rapidez y el riesgo de complicaciones infecciosas será menor.

Predictive factors for synchronous common bile duct stones in patients with cholelithiasis

AbstractBackground: To determine the predictive factors of synchronous common bile duct (CBD) stones, data from 878 consecutive patients who underwent cholecystectomy in a university clinic from June 1991 to June 1996 were retrospectively analyzed. Methods: Based on clinical, biochemical, and ultrasonographic criteria, 194 patients were selected for ERCP, 180 preoperative and 14 postoperative. Results: Cannulation of CBD was successful in 192 (99%) patients. Stones were identified in 62 (32%) patients and sphincterotomy was performed in 56 (90%). Duct clearance was achieved in 43 (77%) cases. There was a high predictive value for the presence of CBD stones in patients with cholangitis, present jaundice, and dilated CBD with evidence of stones on ultrasound (75%, 72%, and 67% respectively). A dilated CBD without stone on ultrasound and elevated liver enzymes had less than 40% positive predictive value. History of previous jaundice, pancreatitis, previously raised liver enzymes, and present pancreatitis was predictive in less than 20% of the cases. Univariate analyses revealed that clinical findings of cholangitis and obstructive jaundice, elevated liver enzymes (previous and present), and ultrasonographic findings of stones in a dilated CBD were significant positive predictors. Subanalysis of each elevated liver enzyme revealed that alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma glutamyl transpeptidase were significant predictors. Both elevated conjugated and total bilirubins were also significant predictors for CBD stones. Conclusion: Multivariate logistic regression analysis on these significant predictors showed that cholangitis (odds ratio [OR]: 10.5), dilated CBD with evidence of stones on ultrasound (OR: 7.4), elevated aspartate transaminase (OR: 2.9), and conjugated bilirubin (OR: 5.3) were jointly significant. The likelihood of having stones in the duct without any of these predictors was 7%, but 99% when all the predictors were positive.

Needlescopic or minisite cholecystectomy.

Abstract. Needlescopic or minisite cholecystectomy is laparoscopic cholecystectomy done through tiny ports from 1.4 mm to 3 mm in size. This refinement of conventional laparoscopic cholecystectomy reduces further the invasiveness of the operation and gives an improved cosmetic effect. This series describes the result of 36 needlescopic cholecystectomies done between February 1996 and April 1997. Patients with acute cholecystitis were excluded. There were two conversions to conventional laparoscopic surgery and no conversions to open surgery. Thirty-four patients were successfully treated by this technique. Analgesic consumption and cosmetic result was superior compared to a previous published series of conventionally done cases in the same department.

Evaluation of a head-mounted display (HMD) in the performance of a simulated laparoscopic task

BackgroundHead-mounted display (HM) units are used in various industries, but they have been tried only recently in surgery. In this study, we evaluated whether a commercially available HMD would improve or impede a laparoscopic task—in this case, suturing.MethodsSix participants performed a total of 120 laparoscopic suture knots in an experimental model. The Olympus FMD011 model with a two-dimensional image was used. The order of each task with or without the head display unit was random. The time to complete each knot was recorded, and the results were analyzed.ResultsThe display unit prolonged the suturing times of the subjets by 10% (p<0.04).ConclusionsIn this experimental model, the HMD we utilized did not appear to improve laparoscopic suturing. More developments, such as improved depth perception and better resolution, may increase its usefulness for laparoscopic tasks.

Nerve-sparing Axillary Dissection Using the da Vinci Surgical System

This is an initial report of a new method of axillary dissection via a periareolar incision and an 8 mm incision in the axilla with the da Vinci Surgical System. The 10× magnification and three-dimensional image, together with the versatility and precision of the robotic telemanipulators, has enabled us to perform nerve-sparing axillary dissection in four patients with invasive ductal carcinoma of the breast undergoing segmental (conservative) excision and level II axillary dissection. The time for the robotic axillary dissection ranged from 30 to 105 minutes (average 70.5 minutes). The average number of lymph nodes retrieved was 13 (11, 11, 13, and 17, respectively). Postoperatively all four patients recovered well and were discharged the next day. The robotic system can enhance the surgeon’s ability by providing a high-definition, magnified, three-dimensional view of the operative field, intuitively controlled articulating instruments, and elimination of tremors; and it has potential benefits for the patient.