Early results of a prospective multicenter study on 500 consecutive cases of laparoscopic colorectal surgery

Background: Prospective randomized multicenter studies comparing laparoscopic with open colorectal surgery are not yet available. Reliable data from prospective multicenter studies involving consecutive patients are also lacking. On the basis of the personal caseloads of specialized surgeons or of retrospective analyses, it is difficult to judge the true effectiveness of this new technique. This study aims to investigate the results of laparoscopic colorectal surgery in consecutive patients operated on by unselected surgeons. Methods: This observational study was begun August 1, 1995, in the German-speaking part of Europe (Germany and Austria) and 43 centers initially agreed to participate. All consecutive cases were documented. All data were rendered anonymous. Analysis was performed on an intention-to-treat basis. The study committee was blinded to the participating center. Results: By the end of the 1st year, 500 patients (M:F ratio 0.83, mean age 62.9 years) had been treated by 18 centers; 269 operations were performed for benign indications and 231 for cancer (palliative and curative). Most operations were done on the distal colon or rectum. An anastomosis was performed in 84%, with an overall leakage rate of 5.3% (colon 3.6% and rectum 11.8%), which required surgical reintervention in 1.7%. The mean operating time was 176 min and showed a decreasing tendency over the period under study. The conversion rate was 7.0% and the overall complication rate 21.4%. The reoperation rate was 6.6%; the most common cause was bleeding. There was one ureteral lesion (0.2%), but urinary tract infections were fairly common (4.8%). A postoperative pneumonia was diagnosed in 1.6% of the cases. No thromboembolic complications were reported. The 30-day mortality rate was 1.4% and overall hospital mortality 1.8%. Conclusions: Laparoscopic colorectal operations are still rare (about 1% of all colorectal operations in Germany). Laparoscopic procedures are more common on the left colon and rectum than on the right colon. The surgical complication rate is acceptable, comparable with rates reported by others for open surgery. Cardiopulmonary and thromboembolic complications were rarely seen. Mortality and surgical morbidity rates do not differ significantly among participating centers. A learning curve, reflected by a shortening of the operating time and a somewhat lower conversion rate, was observed over the observation period. Received: 3 February 1997/Accepted: 22 April 1997     

Laparoscopic Duhamel procedure

Background: Between February 1995 and June 1998, 30 laparoscopic Duhamel pull-through procedures were performed in our department. Methods: Our main aim was to prove the feasibility of the laparoscopic abdominal Duhamel procedure for different localizations of Hirschsprung disease. We used one camera port and three working ports. The sigmoid colon and posterior rectum were mobilized laparoscopically. A standard posterior colo-anal anastomosis was fashioned and a stapler was used for the anterior anastomosis. The top of the rectum was then closed by endo stapler under laparoscopic vision. Results: Thirty patients underwent laparoscopic surgery for this procedure. Three laparoscopic procedures were converted because of technical difficulties. The operative time was 100–330 mn. Oral feeding was started at a mean postoperative time of 2.5 days. Mean postoperative hospitalization was 9 days. Early postoperative complications included 1 anastomotic leak, 1 retrorectal abscess, 2 urinary infections, and 1 evisceration (after conversion). No enterocolitis or enterocolitis-like symptoms were noted. All patients now have daily spontaneous bowel movements. Conclusion: The laparoscopic Duhamel procedure can be performed safely, giving good results. Received: 6 November 1998/Accepted: 12 February 1999     

Elective laparoscopic-assisted colectomy for diverticular disease

Background: Although several recent reports described the different methods utilized for laparoscopic colon resection, only a few of them questioned whether the procedure is appropriate for the surgical treatment of diverticular disease. To assess this question, we performed a retrospective study of 50 consecutive patients operated using laparoscopic assistance to remove the sigmoid colon for diverticular disease. Method: The surgical technique was a laparoscopically assisted procedure that included mobilization of the left colon and vascular ligation laparoscopically and then, via a small abdominal incision, division of the colon, removal of the specimen, and hand-sewn anastomosis. Results: The surgical goal was achieved in 46 cases, with a conversion rate of 8%. The mean operative time was 195 min (range 150–280 min). There was no mortality, and the morbidity rate was 14%. There were no complications directly related to the laparoscopic technique. The mean return of regular bowel habits was 3.2 days, and the median postoperative stay was 10 days. Conclusions: These preliminary results suggest that laparoscopic-assisted sigmoidectomy can be used safely for the surgical treatment of diverticular disease. Received: 30 July 1997/Accepted: 21 January 1998     

Laparoscopic surgery preserves monocyte-mediated tumor cell killing in contrast to the conventional approach

Background: Experimental animal research shows that immunologic defenses against tumor cells are disturbed by surgical trauma, resulting in an increased rate of tumor implantation and the growth of subsequent metastases. Minimally invasive surgery is associated with a preservation of postoperative immunologic functions and, in animal models, with decreased tumor growth. The objective was to study the influence of several surgical procedures, approached conventionally and laparoscopically, on interleukin-6 (IL-6) and monocyte-mediated cytotoxicity (MMC). Methods: Five groups of five patients each were included in this prospective study: laparoscopic cholecystectomy (minor trauma) group, Nissen fundoplication (laparoscopic and conventional as moderate trauma) groups, and sigmoid colectomy (laparoscopic and conventional as major trauma) groups. Preoperatively, 1 and 4 days after surgery, IL-6 and MMC against SW948 colon cancer cell line were determined. Results: The IL-6 levels differed significantly between the three laparoscopic procedures (p= 0.004) and increased according to the degree of trauma. There was no significant difference in MMC between the three laparoscopic procedures. However, MMC was suppressed after conventional procedures and preserved after laparoscopic procedures (p= 0.001). There was no correlation between IL-6 levels and changes in MMC. Conclusions: More extensive laparoscopic procedures induce increased levels of IL-6, reflecting higher levels of trauma. Conventional surgical procedures result in depressed MMC in the postoperative period. After laparoscopic procedures, MMC is preserved. These findings may be of importance in preventing implantation and growth of cancer cells spread by surgical manipulation. Received: 10 December 1998/Accepted: 25 March 1999     

Laparoscopic treatment vs open surgery in the solution of major incisional and abdominal wall hernias with mesh

Background: Despite being one of the most exact indications, laparoscopic treatment of eventrations and ventral hernias is barely known among the array of laparoscopic techniques. Methods: A total of 60 patients were assigned at random over a 3-year period to two homogeneous groups to be operated on for major ventral hernias with mesh. Half of them were operated upon laparoscopically and the rest with open surgery. Early and longer-term complications were analyzed, as were operative time and postoperative hospital stays. Results: The two groups were homogeneous in terms of demographic and clinical characteristics. The group that was operated on laparoscopically presented a lower rate of postoperative and longer-term complications; similarly, surgery time was significantly lower (p < 0.05). Hospitalization time was also significantly lower than in the group undergoing conventional open surgery (p < 0.05). Conclusions: Laparoscopic treatment of postoperative eventration and primary ventral hernia reduces complications and relapse rates, eliminates reintervention through mesh infection, reduces operative time, and considerably shortens the hospital stay. Received: 22 December 1997/Accepted: 18 August 1998     

Laparoscopic repair of perforated duodenal ulcer

Background: A series of 100 consecutive patients with perforated peptic ulcer were prospectively evaluated in a multicenter study. The feasibility of the laparoscopic repair was evaluated. Methods: All patients had peritonitis, 20% were in septic shock, and 57% had delayed perforation. Conversion to laparotomy was necessary in eight patients. The morbidity rate was 9% and mortality rate 5%. Results: The mean delay of postoperative gastric aspiration (mean 3.4 days) and resumed food intake (mean 4.4 days) as well as the mean postoperative hospital stay (mean 9.3 days) were comparable to conventional surgery, but postoperative comfort was subjectively increased by laparoscopy and noticed by all laparoscopic surgeons participating in this study. Conclusions: Laparoscopic repair of perforated peptic ulcer proves to be technically feasable and carries an acceptable morbidity and mortality rate, compared with conventional surgery. Received: 16 August 1996/Accepted: 1 April 1997     

Laparoscopically assisted bowel surgery for inflammatory bowel disease

Background: Laparoscopic bowel surgery was evaluated in 44 consecutive patients who underwent surgery for inflammatory bowel disease (IBD). We studied feasibility, results, and final outcome. Methods: At two academic institutes, 44 laparoscopically assisted colectomies and laparoscopic ileostomies or colostomies were attempted. All patients had histologically proven IBD and no prior surgery for IBD. Loop ileostomy (n= 4), end colostomy (n= 1), ileocecal resection (n= 26) and (procto)colectomy (n= 13) were performed. All resections were laparoscopically assisted with extracorporal resection and anastomosis. Results: Only in two patients (ileocecal resection in both) was conversion to open surgery necessary. Two patients with laparoscopic ileocolic resection had intra-abdominal abscesses, which were drained percutaneously in both. One patient in the laparoscopically assisted colectomy group had a subphrenic abscess that was drained percutaneously, and one patient had a generalized candidiasis. Conclusions: Laparoscopically assisted colectomies can be performed safely in treating IBD. The laparoscopic method with use of a small vertical umbilical or Pfannenstiel's incision seems acceptable with regard to operating time and overall costs, also allowing superior cosmesis to be maintained. Received: 12 August 1998/Accepted: 13 January 1999     

Laparoscopically assisted intestinal resection in 88 patients with Crohn's disease

Background: Experience with 94 resections in 88 patients with Crohn's disease using advanced laparoscopic techniques is reported. Records of patients who underwent intestinal resection for Crohn's disease between August, 1993 and November, 1998 were reviewed. Indications, operative findings, clinicopathologic, and postoperative data were recorded. Methods: In this study, the mean age was 37 years (range, 16–70 years), and 55% of the participants were women. Indications for surgery included obstruction (64 cases), pain (22 cases), peritonitis (1 case) and abscess (1 case). Seventy patients underwent ileocolic resection, 28 of whom had a previous history of one or two ileocolic resections. Eight of these patients had additional procedures including tubal ligation (1), sigmoidectomy (1), cholecystectomy (3 cases), and enterectomy (3 cases). Small bowel resection (13 cases), right hemicolectomy (3 cases), subtotal colectomy (3 cases), anterior rectal resection (2 cases), and sigmoid resection (3 cases) were performed in the remaining patients. All but one procedure were completed laparoscopically with extracorporeal anastomosis. The average length of intestine resected was 33 cm (range, 10–92 cm). Forty-one patients had 58 fistulae between ileum, jejunum, mesentery, colon, abdominal wall, skin, or bladder. Mean blood loss was 168 ml (range, 30–800 ml) and mean operative time was 183 min (range, 96–400 min). Results: More than 85% of the patients were tolerating a liquid diet on the first postoperative day. Average length of hospital stay was 4.2 days (range, 3–11 days). Complications included anastomotic leak necessitating reoperation, stricture requiring endoscopic dilation, hemorrhage treated expectantly, urinary tract infection, pulmonary embolus, line sepsis, and early postoperative intestinal obstruction (7 cases) requiring reoperation in three cases. Conclusions: Experience with both advanced laparoscopic techniques and conventional surgery for inflammatory bowel disease allowed successful laparoscopic management of patients with complicated Crohn's disease. Received: 29 August 1998/Accepted: 22 January 1999     

Laparoscopic treatment of hydatid cysts of the liver and spleen

Background: The short-term results from laparoscopic treatment of hydatid cysts of the liver and spleen were reported previously. The procedure was shown to be feasible and safe, offering the advantages of laparoscopic surgery. This is the first report on the long-term follow-up of this operation in a large group of patients. Methods: In this study, 108 hydatid cysts of the liver and spleen in 83 consecutive patients (43 males [52%] and 40 females [48%]) were approached laparoscopically. The mean age of the patients was 40 years (range, 13–85 years). There were 104 liver cysts and 4 spleen cysts. The liver cysts were located in the right lobe in 42 patients (53%), in the left lobe in 21 patients (26%) and in both lobes in 16 patients (21%). Of the 104 cysts, 44 (42%) were uniloculated and 60 (58%) were multiloculated. Results: All cysts were approached laparoscopically. The mean operative time was 80 min (range, 40–180 min). The conversion rate was 3%. The mean hospital stay was 3 days (range, 2–7 days). There were no mortalities, and complications occurred in nine patients (11%). All were managed conservatively except one patient in whom a laparotomy was needed. All patients were followed up for a mean period of 30 months (range, 4–54 months) with serological testing and ultrasonography if needed. In three patients (3.6%) recurrence of the disease developed. Conclusion: The laparoscopic approach to uncomplicated hydatid cysts of the liver and spleen is a safe and effective option with favorable long-term results. Received: 27 August 1998/Accepted: 13 July 1999     

Development of gallstone surgery in Germany

Background: The aim of this study was to evaluate the development and outcome of laparoscopic gallstone surgery in Germany in a nationwide representative survey. Methods: A written questionnaire, which included 111 structured items about diagnostic and therapeutic approaches, number of procedures, complications, and mortality, was sent to 449 randomly selected German surgeons (20% of the registered German general surgeons) annually from 1991 to 1994. Results: A total number of 72,455 operations for gallstone disease was reported. The frequency of laparoscopic cholecystectomies increased from 24.9% in 1991 to 65.3% in 1993. In 1994, 92% of the polled surgeons were using the laparoscopic approach as compared with 10% in 1991. The results demonstrated significantly lower morbidity (6% vs. 9%) and mortality figures (0.14–0.45%) than for the open procedure. The percentage of common bile duct (CBD) injuries was significantly higher for the laparoscopic group than for the open treatment group (0.7% vs. 0.4%). In 1993 the data shows a significant decrease in surgical complications such as bleeding, CBD injuries, and relaparotomy rate for the laparoscopic procedures. No changes were seen in the mortality rate. Conclusions: These results show learning curves that project a positive trend in the overall risk incurred by laparoscopic cholecystectomy in Germany during the past few years. This can be seen as an effect of better training and experience. Obviously, CBD injuries and technical problems especially have passed their peak of incidence. Received: 24 October 1997/Accepted: 28 August 1998     

Laparoscopic secondary antireflux procedure after PEG placement in children

Background: This study investigates the feasibility of performing a subsequent laparoscopic antireflux procedure after former placement of a percutaneous endoscopic gastrostomy (PEG). Methods: Between 1997 and 1998, five patients with a gastrostomy in place presented with an indication for laparoscopic antireflux procedure due to persisting vomiting. Results: All patients were managed laparoscopically with a four-trocar technique. Conclusions: Primary PEG placement has no adverse effects on a later secondary antireflux procedure. In some cases, four rather than five trocars can be used. Received: 7 December 1999/Accepted: 7 March 2000/Online publication: 29 August 2000     

Postoperative complications of laparoscopic-assisted colectomy

Background: This study was performed to prospectively assess the complications of 118 consecutive patients who underwent laparoscopic assisted colorectal resections. Methods: The variables included were: indication for surgery, type of resection, duration of operation, duration of postoperative ileus, length of hospital stay, port-site recurrence, and complications in relation to the laparoscopic technique. Results: 118 Laparoscopic-assisted procedures were performed between July 1992 and October 1995. Surgical indications were: 106 patients for colonic malignancy, six for diverticulitis, two for Crohn's disease, two for benign polyps, one for endometriosis, and one for ischemic colitis. Fifteen patients required conversion to open techniques for completion of the operations (12.7%). The mean operating time was 168.8 min. The amount of operative blood loss was 98 ml. The mean time for passing flatus was 36 ± 16 h. Mean postoperative stay was 5.4 (range 3–13) days. Eight patients (6.8%) sustained complications: four unrelated to laparoscopy (three wound infection, one anastomotic leak); and four complications related to the laparoscopic approach: one small-bowel obstruction, one trocar injury, one rotation of the anastomosis, and one misdiagnosed synchronous adenocarcinoma. Conclusions: We suggest that with the development of improved technical devices and more experience, the indications for laparoscopic colectomy should continue to expand. The low incidence of infectious complications suggests an important role for the laparoscopic approach to colorectal surgery. Received: 25 March 1996/Accepted: 8 July 1996     

Small bowel obstruction

Background: This is a retrospective review of our experience using a laparoscopic approach in the treatment of acute and chronic small bowel obstruction (SBO). Materials and methods: Of 136 patients hospitalized in our institutions for acute (94 cases: 69.1%) and chronic (42 cases: 30.8%) SBO, from January 1994 to March 1998, 63 (46.3%) were approached laparoscopically. The etiology was accurately diagnosed in 58 cases (92%), and it was possible to treat it laparoscopically in 82.5% (52 of 63 cases). In the remaining 11 cases (17.4%), a formal laparotomy was needed for bowel resection, due to an ischemic small bowel or for malignant disease. Results: Overall, 82.5% of our cases were successfully treated laparoscopically. Conclusions: We conclude that, in experienced hands, laparoscopy is an excellent diagnostic and, in the majority of cases, a therapeutic surgical approach in selected patients with acute or chronic SBO. Received: 30 June 1998/Accepted: 12 February 1999     

Laparoscopic colorectal surgery

Background: A variety of parameters can affect the outcome of laparoscopic colorectal surgery. All consecutive laparoscopic colorectal procedures (LCP) were analyzed in an attempt to define an operative time curve for different categories of procedures. Additionally, impacts of case number and procedure type on length of procedure were assessed. Methods: Our computerized data system was reviewed for all patients who underwent LCP in a 4-year period. Parameters reviewed included age, sex, surgical indications, procedures performed, length of procedure, intraoperative and postoperative complications, incidence and causes for conversion, duration of postoperative ileus, and hospital stay. Results: Between August 1991 and December 1995, 175 patients with a mean age of 48.4 (range 15–88) years underwent LCP. Patients were divided chronologically into five consecutive groups. Procedures were classified as either basic or complex. Complex procedures were those in which there was either a fixed tumor, an abscess or fistula, or extensive intraabdominal adhesions from prior surgery. Complex procedures performed each year ranged from 37% to 66%. As well, the percentage of patients with adhesions increased from 17% in 1991 to 29% in 1995. Despite increased difficulty, the intraoperative complication rate fell significantly from 29% in 1991 to 8% in 1995 (p < 0.005). Additionally, the operative length decreased from a mean of 201 min in 1991 to a mean of 141 min in 1995 (p < 0.05). Conclusion: The rapid improvement in these parameters may reflect both ascents in the learning curve and change in type of procedure. Adhesions, due to prior surgery or inflammation making dissection tedious, is the most important technical factor which effects operation time (p < 0.001). However, despite increased complexity, operating time decreased, reflecting improved skills. Thus, the experienced laparoscopic surgeon can increase the spectrum of applications with expectations of shorter operations and lower complication rates. Received: 14 March 1996/Accepted: 31 July 1996     

Core temperature changes during open and laparoscopic colorectal surgery

Background: Perioperative hypothermia increases the morbidity of surgery. However, the true incidence of hypothermia during prolonged laparoscopic surgery is still unknown. To investigate this issue, we compared the temperature change between patients undergoing open and laparoscopic colorectal surgery. Methods: Sixty consecutive patients who were undergoing laparoscopic (33) or open (27) colorectal surgery had a transesophageal temperature probe placed after induction of anesthesia. Core temperature values were measured at 15-min intervals. Results: The groups were not statistically different with respect to age, sex, body surface area, or initial transesophageal temperature. The type of surgical access (open or laparoscopic) caused no difference in the incidence of hypothermia. The use of a forced-air warming device produced significantly less hypothermia during laparoscopic surgery. Men showed significantly less variability in temperature change than women. Conclusions: The incidence of hypothermia in open and laparoscopic colorectal surgery is similar. Forced-air warming devices are of value in prolonged laparoscopic surgery. A gender difference in the response to a hypothermic situation has not been previously reported. This finding warrants further investigation. Received: 28 April 1998/Accepted: 18 August 1998     

The value of 24-h pH study in evaluating the results of laparoscopic antireflux surgery in children

Background: The performance of laparoscopic antireflux surgery is steadily increasing among pediatric surgeons. Different techniques are being used. However, due to a lack of standardized follow-up methods, postoperative results are difficult to compare. In this study, we describe the results of postoperative 24-h pH study as an objective criterion for evaluating the results of laparoscopic Thal antireflux surgery. Methods: In a prospective study, 53 patients underwent a laparoscopic Thal procedure. Preoperatively, all patients were subjected to 24-h pH monitoring, an upper GI series, and esophagogastroscopy. pH monitoring was performed 3 months postoperatively to evaluate the effect of the fundoplication. Esophagogastroscopy was repeated in case of preoperative esophagitis. Results: In one patient, the laparoscopy was converted to an open procedure. Feeding was commenced on day 1 in 49 of the 53 children. Mean hospitalization time was 4.4 days. One patient was reoperated for a too-tight fundoplication, and two patients died of unrelated causes. Ultimately, 44 of 50 children (88%) were free of symptoms; however, 11 of 41 children (25%) still displayed pathological reflux on pH monitoring. Conclusions: The Thal fundoplication can be performed laparoscopically in children. Children have a quick recovery, and hospitalization is short (4.4 days). At follow-up, nearly 90% of the children are free of symptoms. However, 25% still have pathological reflux as measured with pH monitoring. Therefore, questionnaires alone are not a sufficient means of measuring outcome postoperative. pH monitoring is a valuable additional tool for the objective postoperative evaluation of the results of (laparoscopic) antireflux procedures. Received: 9 July 1998/Accepted: 6 October 1998     

Anastomosis level and specimen length in surgery for uncomplicated diverticulitis of the sigmoid

Background: Extent of bowel resection and level of anastomosis are unsettled issues of surgery for diverticulitis of the sigmoid. The aim of this study was to compare the adequacy of open colon resection (OCR) with that of laparoscopic colon resection (LCR) for uncomplicated diverticulitis of the sigmoid (UDS), specifically addressing level of anastomosis and length of specimen. Methods: Comparisons were made between 40 selected patients undergoing LCR for UDS between 1992 and 1994 and 35 diagnosis-matched controls who previously underwent OCR by the same surgeons at the same institution. Results: The OCR and LCR patients were well-matched for age, gender, weight, ASA grade, duration of symptoms, and number of previous admissions. There were no significant differences, respectively, between OCR and LCR patients in morbidity rates (2 vs. 5, p= 0.33) and rates of mobilization of the splenic flexure (17:18 vs. 29:11, p < 0.1). Specimen length (18 cm vs. 11 cm, p≪ 0.01), colosigmoid vs. colorectal anastomosis (24:11 vs. 1:39, p≪ 0.01), and presence of inflammatory cells at the proximal resection margin (2 vs. 11, p= 0.02) were significantly different. The OCR patients had statistically longer follow-up than LCR patients (63 months vs. 46 months, p≪ 0.01). Recurrent diverticulitis rates were 9.6% and 2.7% after OCR and LCR, respectively (3 vs. 1, p= 0.73). Conclusions: Inadequate sigmoid resection should prompt diligence to take down the splenic flexure placing the distal anastomotic margin on the rectum to ensure adequate surgery. Received: 12 August 1997/Accepted: 16 November 1997     

Laparoscopic repair of recurrent inguinal hernias after endoscopic herniorrhaphy

Background: Although the recurrence rate for endoscopic herniorraphy is low (0–3%), it is still debatable whether these recurrences should be corrected laparoscopically or by the conventional method. The aim of this study was to investigate whether these recurrences can be repaired by means of the laparoscopic approach with acceptable complication and recurrence rates. Methods: From October 1992 to December 1997, 34 patients with recurrent inguinal hernias at physical examination underwent surgery at our institutions. All the recurrences occurred following endoscopic inguinal hernia repair with mesh prostheses. The recurrences were repaired endoscopically using a transabdominal approach. Depending on the size of the defect, a new polypropylene mesh was used. Results: Mean surgery time was 69 min. There were no conversions to the anterior approach. After a mean follow-up of 35 months, no recurrences had been diagnosed. Conclusion: The transabdominal preperitoneal approach is a reliable technique for recurrent inguinal hernia repair after previous endoscopic herniorrhaphy. Received: 7 September 1998/Accepted: 13 October 1998     

Intraperitoneal bile collections after laparoscopic cholecystectomy

Background: Bile leakage is more common after laparoscopic cholecystectomy than after open surgery. In our department, the rate of postoperative bile collections after open surgery is 0.2% vs 0.6% after laparoscopic cholecystectomy. Methods: We studied 13 cases of intraperitoneal bile collection without common bile duct damage drawn from a total of 5,200 laparoscopic cholecystectomies (0.23%). Clinical presentation, symptoms, method of diagnosis, causes, time of diagnosis, correlation of time of diagnosis with definitive treatment, and postoperative results were analyzed. Results: The symptoms appeared between the 5th and 8th postoperative days. They were observed in patients with either chronic or acute cholecystitis. The main causes were misapplication of clips at the cystic duct and open Luschka's duct. Ultrasound failed for early recognition of bile collections. The definitive diagnosis was made by repeat ultrasonography, CAT scan, and ERCP. Conclusion: The ideal treatment in these cases is a minimally invasive procedure, but since the diagnosis is frequently delayed, open surgery is performed in the majority of patients. However, there were no mortalities in this group of patients. Received: 12 November 1998/Accepted: 15 July 1999/Online publication: 29 August 2000