Marc A. Reymond

Laparoscopic resection of sigmoid diverticulitis

AbstractBackground: In the large bowel, resection of the sigmoid colon is the most commonly performed laparoscopic intervention because large bowel lesions often are located in this part of the bowel and the procedure technically is the most favorable one. A number of publications involving case series or the results of highly experienced individual surgeons already have confirmed the feasibility of laparoscopic resection in cases of diverticulitis. The aim of the present prospective multicentric investigation was to check the results obtained by a large number of surgeons performing laparoscopic resection of the sigmoid colon for diverticulitis in various stages of severity.n Results: Between January 8, 1995 and January 1, 1998, the Laparoscopic Colorectal Surgery Study Group recruited 1,118 patients to the prospective multicenter study. Diverticulitis of the sigmoid colon, which accounted for 304 cases, was the most common indication for laparoscopic intervention. In most of these patients undergoing laparoscopic surgery (81.9%), the diverticulitis manifested as acute phlegmonous peridiverticulitis, recurrent attacks of inflammation, or stenosis. Complicated forms of diverticulitis in Hinchey stages I to IV and late complications of chronic diverticular disease with fistula formation and bleeding accounted for only 18.1% of the cases. For the overall group, the conversion rate was 7.2%. Patients with less severe diverticulitis (i.e., those presenting with peridiverticulitis, stenosis, or recurrent attacks of inflammation) had a conversion rate of 4.8% and the rate for complicated cases was 18.2%. Regarding laparoscopically completed interventions, 3 of 282 patients died (1.1%). In the group of patients with peridiverticulitis, stenosis, or recurrent attacks of inflammation the overall complication rate was 14.8%. The group with perforated diverticulitis in Hinchey stages I to IV or those with fistula and bleeding, the corresponding rate was 28.9%, and after conversion it was 31.8%.n Conclusions: Laparoscopic colorectal interventions in sigmoid diverticulitis are, for the most part, carried out as elective procedures for peridiverticulitis, stenosis, or recurrent attacks of inflammation. The conversion, complication, and mortality rates associated with these interventions are acceptable. Laparoscopic procedures in Hinchey stages I to IV sigmoid diverticulitis and in the presence of fistula and bleeding are more likely to be associated with complications, and should be carried out only by highly experienced laparoscopic surgeons.

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

AbstractBackground: 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.n 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.n 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%.n 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.

Prospective multicenter study of the quality of oncologic resections in patients undergoing laparoscopic colorectal surgery for cancer

PURPOSE: Laparoscopic colorectal surgery for cancer is currently under discussion. Results of large, randomized studies will not be available for a number of years yet. This study analyses the results of such resections in consecutive patients operated on by unselected surgeons. METHODS: A prospective, observational, multicenter study was initiated on August 1, 1995, in the German-speaking countries of Europe. One year after initiation of the study, findings are presented with respect to the quality of oncologic resections. RESULTS: Of 500 operations, 231 (46 percent) were performed for cancer, 167 (33 percent) with a curative intent. The most common curative resections were as follows: 63 anterior rectum resections (38 percent), 51 sigmoid resections (30 percent), and 27 abdominoperineal resections (16 percent). Segmental resections were performed in 20 patients (12 percent). Intraoperative tumor spillage was reported in 2 percent. Mean number of lymph nodes harvested was 13 (confidence interval, 5–95 percent; range, 11.5–14.6) and positive lymph nodes harvested was 2.2 (confidence interval, 5–95 percent; range, 0.9–3.4). Significant differences were noted between participating centers in terms of number of lymph nodes resected (P<0.0001). Distal and proximal resection margins were tumorfree in every case. Lateral margins were tumor-free when examined. In the case of 63 curative anterior resections, the mean distal resection margin was 39 (confidence interval, 5–95 percent; range, 33–45) mm, and in 8 of these resections, it was less than 20 mm. Mean blood loss was 344 (confidence interval, 5–95 percent; 292–396) ml, and 21 percent of patients received blood transfusions. CONCLUSIONS: These data document that the average quality of laparoscopic colorectal procedures for cancer is satisfactory but differs among surgeons.

The pathogenesis of port-site recurrences.

The major factors underlying the seeding of tumor cells during laparoscopy are mechanical, with CO2 playmg only a secondary role The peritoneal wound is of great importance, especially m advanced tumor stages, when cells are present within the abdominal cavity Most reported port-site metastases were found within the extraction port when no protective measures were taken Gasless laparoscopy is no solution to the problem, since numerous port-site metastases have been described after thoracoscopy, during which no CO2 is used The surgeon’s role in the seeding of tumor cells is based on tumor perforation, excessive manipulation, and replacement of trocars This presumably explains the large differences (0% and 21%) in the reported incidence of port-site metastases Prospective studies now show that it is possible to keep the incidence of abdominal wall metastases to about 1%—which is comparable to that seen m open surgery—by the use of a meticulous operating technique and preventive measures

Predictive value of nuclear betacatenin expression for the occurrence of distant metastases in rectal cancer

PURPOSE: Adenomatous polyposis coli protein, glycogen synthetase kinase-3-beta, T cell transcription factor/lymphoid enhancer-binding factor, and beta-catenin modulate cell differentiation and proliferation via the expression of effector genes. It has recently been postulated that betacatenin is a potent oncogene of sporadic colorectal carcinogenesis and a prognostic tumor marker. Our aim was to investigate whether the nuclear overexpression of betacatenin, possibly caused by mutations in exon 3 of betacatenin (CTNNB1), is correlated with distant metastatic spread or disease-free survival in rectal carcinoma. METHODS: Immunohistochemical analysis was performed with an anti-beta-catenin-monoclonal antibody on paraffin sections of two groups of patients (n=2 × 77) with rectal carcinoma curatively treated by surgery alone. The patients selected were all free of local disease, to exclude surgical influence. Patient groups were matched for age, gender, International Union Against Cancer stage, and year of operation (1982 to 1991) and differed only in subsequent metachronous distant metastatic spread. Follow-up was prospective (median, 9.6 years). Three staining patterns were defined: membranous (normal), diffuse cytoplasmic (pathologic), and intense nuclear staining (pathologic). When intense nuclear staining was defined, the specimen was microdissected. Then, DNA was isolated, polymerase chain reaction-amplified, and sequenced to detect mutations in exon 3. RESULTS: Nuclear overexpression of beta-catenin correlated neither with distant metastatic spread (chisquared, 0.37;P=0.79) nor with disease-free survival (log-rank with trend,P=0.62). No mutations were found in the area of the serine/threonine-kinase glycogen synthetase kinase-3-beta-phosphorylation site in exon 3 (CTNNB1) of beta-catenin. CONCLUSION: Although beta-catenin seems to play an important role in early colorectal carcinogenesis, its value as a prognostic marker is questionable. It must be assumed that metastatic ability is determined by other factors than the disturbance of the beta-catenin T cell transcription factor/lymphoid enhancer-binding factor cascade and that other mechanisms might cause the observed nuclear translocation of beta-catenin.

FEHLER UND GEFAHREN IN DER ONKOLOGISCHEN LAPAROSKOPISCHEN CHIRURGIE

Summary. Oncological problems associated with laparoscopic colorectal surgery with curative intent include port site metastases, inadequate radicality, seeding of tumour cells through unprotected recovery of the surgical specimen, faulty surgical technique, and failure to observe the technical and/or oncological limitations applicable to certain tumour sites. Investigations so far reported reveal a preponderance of mechanical pathogenesis of port site metastases caused by the contamination of trocar entry ports by tumour cells borne on instruments, trocars and resected material. This suggests that appropriate precautionary measures could resolve the problem. It appears that the CO2 pneumoperitoneum plays only a minor role in the development of port site metastases. Owing to a lack of long-term data, the oncological radicality of laparosopic resections for colorectal carcinoma cannot be assessed; merely a few reports on the number of lymph nodes removed during such operations have been published. Nevertheless, it would appear that fewer lymph nodes were removed than with comparable conventional surgery. However, a more accurate analysis needs to take account of the fact that the indication for laparoscopic surgery is determined by the size and location of the tumour. The many potential pitfalls and hazards of oncological laparoscopic surgery make it mandatory that such interventions should be done only within the framework of prospective clinical studies covering limited indications. Randomized prospective studies to cover all tumour stages and sites cannot be recommended.Zusammenfassung. Die onkologischen Probleme bei laparoskopisch colorectalen Eingriffen in kurativer Intention bestehen im Auftreten von Port-site-Metastasen, in einer inadäquaten Radikalität, einer Tumorzellverschleppung durch ungeschützte Präparatebergung und unzureichende Operationstechnik sowie Nichtbeachtung technisch-onkologischer Grenzen bei bestimmten Tumorlokalisationen. Die bisher vorliegenden Untersuchungen ergeben eine mehr mechanische Pathogenese der Port-site-Metastasen durch Verschleppung von Tumorzellen in die Trokareinstichstellen über Instrumente, Trokare und Resektionspräparate. Durch entsprechende Vorsichtsmaßnahmen scheint somit eine Vermeidung möglich. Das CO2-Pneumoperitoneum spielt anscheinend eine untergeordnete Rolle bei der Entstehung der Port-site-Metastasen. Die onkologische Radikalität laparoskopischer Eingriffe beim colorectalen Carcinom kann bei fehlenden Langzeitdaten zur Zeit nicht beurteilt werden. Es liegen lediglich vereinzelte Untersuchungen zur Zahl der bei den Eingriffen mitentfernten Lymphknoten vor. Die Anzahl scheint nicht die bei vergleichbaren offenen Resektionen zu erreichen, eine genauere Analyse müßte jedoch die selektionierten Indikationen nach Tumorgröße und -lokalisation berücksichtigen. Die Vielzahl der möglichen Fehler und Gefahren der onkologischen laparoskopischen Chirurgie führt zu der klaren Forderung, daß die Eingriffe nur innerhalb von prospektiven klinischen Studien mit selektionierten Indikationen erfolgen sollten. Eine prospektiv randomisierte Studie für alle Tumorstadien und -lokalisationen ist vor diesem Hintergrund kritisch zu werten.

The Pneumoperitoneum and Its Role in Tumor Seeding

Port site recurrences (PSR) are abdominal wall recurrences that occur within a trocar site after cancer laparoscopy and that are not associated with peritoneal carcinosis. The short clinical delay of occurrence of PSR (median 190 days in colorectal cancer) suggests a massive cell seeding into the abdominal wall (over 106 cells) during the operation. In human and animal studies, CO2 was not able to aerosolize large numbers of tumor cells using pressures of 8–15 mm Hg, even though isolated mesothelial cells have been found in the aerosol. Such large numbers of tumor cells have only been demonstrated on instruments and trocars. PSR occur not only after CO2 laparoscopy, but also after thoracoscopy, where no CO2 is used. Gaseless laparoscopy was able to reduce, but not to eliminate port site contamination in animal models. Tumor growth was enhanced in numerous animal models using CO2, suggesting an adjuvant effect on tumor growth in the trocar wound. Nevertheless, reported clinical incidences between 0 and 21% suggest that PSR might be a surgeon-related variable dependent mainly on experience and technical expertise. Technical measures have been proposed that might reduce the incidence of PSR.

DCC protein as a predictor of distant metastases after curative surgery for rectal Cancer

PURPOSE: The aim of this study was to determine the value of DCC (deleted in colorectal cancer) protein for predicting metachronous distant metastases after curative surgery for rectal cancer. The DCC protein—for which a gene has been located on chromosome 18q—has recently been reported to have a prognostic value in colorectal cancer. This finding might have implications for treatment of International Union Against Cancer Stage II rectal carcinoma, in which distant metastases will develop in 14 percent of patients despite optimal surgery. METHODS: Paraffin-embedded tissues from 85 patients who developed distant metastases, but no local recurrence, after curative surgery for rectal cancer were matched with 85 samples from patients who remained disease-free. Matching criteria were tumor stage, age, gender, and date of surgery. Expression of DCC protein was assessed using immunohistochemistry. End points of follow-up were recurrence of disease and death. Mean follow-up was 9.6 years. No patient received either local or systemic adjuvant therapy. RESULTS: The DCC protein was found to be expressed in 64.9 percent of tumor samples. Nonexpression of DCC protein had an negative influence on survival (P=0.03). For all tumor stages together, sensitivity of the test for subsequent occurrence of distant metastases was 42 percent and specificity was 71 percent. In Stage II cancers, the positive predictive value was 19 percent, and the negative predictive value was 88 percent. CONCLUSIONS: Our results confirm that DCC protein is a useful prognostic marker in patients with rectal carcinomas, but the positive predictive value of DCC protein for occurrence of metachronous metastases does not appear to be sufficient to justify adjuvant therapeutic measures in Stage II rectal cancer.

Port-Site and Wound Recurrences in Cancer Surgery

Definition.- Abdominal wall recurrences in open surgery.- Port site recurrences in open surgery.- Port site recurrence in thoracoscopic surgery.- Pathogenesis.- Prospective randomized trials.- Natural history.- Prevention.- Treatment.- Perspectives.

Pitfalls and hazards in oncological laparoscopic surgery

Oncological problems associated with laparoscopic colorectal surgery with curative intent include port site metastases, inadequate radicality, seeding of tumour cells through unprotected recovery of the surgical specimen, faulty surgical technique, and failure to observe the technical and/or oncological limitations applicable to certain tumour sites. Investigations so far reported reveal a preponderance of mechanical pathogenesis of port site metastases caused by the contamination of trocar entry ports by tumour cells borne on instruments, trocars and resected material. This suggests that appropriate precautionary measures could resolve the problem. It appears that the CO2 pneumoperitoneum plays only a minor role in the development of port site metastases. Owing to a lack of long-term data, the oncological radicality of laparosopic resections for colorectal carcinoma cannot be assessed; merely a few reports on the number of lymph nodes removed during such operations have been published. Nevertheless, it would appear that fewer lymph nodes were removed than with comparable conventional surgery. However, a more accurate analysis needs to take account of the fact that the indication for laparoscopic surgery is determined by the size and location of the tumour. The many potential pitfalls and hazards of oncological laparoscopic surgery make it mandatory that such interventions should be done only within the framework of prospective clinical studies covering limited indications. Randomized prospective studies to cover all tumour stages and sites cannot be recommended.