Anthony J. Simons

Laparoscopic-assisted colectomy learning curve

PURPOSE: The purpose of this paper is to establish the number of cases necessary to master laparoscopic removal of the left or right colon. METHODS: Data were obtained by chart review and by individually completed questionnaires. RESULTS: A total of 144 laparoscopic-assisted or intracorporeal right or left hemicolectomies were completed by four surgeons at separate institutions. Questionnaires were completed by each surgeon for each sequential hemicolectomy, and data concerning the type of surgery and total operating time were recorded. Times were plotted to diagram individual learning curves for each surgeon, and data grouping methods were used to determine the curve for each surgeon as well as for the combined data base. Learning was said to have been completed when the surgeons operative time reached a low point and subsequently did not vary by more than 30 minutes. A total of 78 right colectomies and 66 left colectomies were completed by the group. Respectively, each surgeon appeared to learn the procedure after 16, 21, 11, and 6 cases. When the entire database was analyzed as a whole, it was shown that between 11 and 15 completed colectomies were needed for learning, after which operative times remained relatively stable. CONCLUSIONS: This analysis, using total operative time as an indication of learning, shows that approximately 11 to 15 completed laparoscopic colectomies are needed to comfortably learn this procedure.

Wound recurrence following laparoscopic colon cancer resection

INTRODUCTION: Multiple case reports have suggested that laparoscopic resection of colon cancer may alter the pattern or incidence of cancer recurrence. All reports lack a significant denominator to evaluate the incidence of surgical wound recurrence. We hypothesized that wound recurrence incidence is not increased by laparoscopic resection of colon cancer. METHODS: A prospective registry was initiated under the auspices of The American Society of Ccolon and Rectal Surgeons, American College of Surgeons, and Society of American Gastrointestinal Endoscopic Surgeons in 1992. Patients having laparoscopic colon resection were voluntarily entered and followed until June 1995. Recurrences were evaluated by the primary surgeon and reported to the registry. RESULTS: A total of 504 patients treated for cancer were identified in the registry. A minimum follow-up of one year was obtained for 480 of 493 evaluable patients (97.4 percent). Wound recurrence was identified in five patients (1.1 percent). Recurrence status was unknown in 18 patients (3.8 percent). CONCLUSION: Wound recurrence rates appear to be low. Although length of follow-up is limited, patterns of recurrence from previous studies suggest that 80 percent of recurrences should have occurred within one year. Given the limitations of a Phase II study, the hypothesis that recurrence rate is low is supported. However, prospective randomized trials are needed to establish if any difference in wound recurrence rates after laparoscopic or open resection of colorectal cancer exists.

Intra-abdominal abscesses following laparoscopic and open appendectomies

Recent findings in a small number of studies have suggested a trend toward increased infectious complications following laparoscopic appendectomy. The purpose of the present review was to evaluate the incidence of postappendectomy intra-abdominal abscess formation following laparoscopic and open appendectomies. Using the surgical database of the Los Angeles County-University of Southern California Medical Center, we reviewed the records of all appendectomies performed at the center between March 1993 and September 1995. Incidental appendectomies as well as appendectomies in pediatric patients under the age of 18 years were excluded. A total of 2497 appendectomies were identified; indications for these procedures included acute appendicitis in 1422 cases (57%), gangrenous appendicitis in 289 (12%), and perforated appendicitis in 786 (31%). The intraoperative diagnosis made by the surgeon was used for classification. A two-tailedP value of <0.05 was considered significant. There was no significant difference in the rate of abscess formation between the groups undergoing open and laparoscopic appendectomies for acute and gangrenous appendicitis. In patients with perforated appendicitis, a total of 26 postappendectomy intra-abdominal abscesses occurred following 786 appendectomies for an over-all abscess formation rate of 3.3%. Eighteen abscesses occurred following 683 open appendectomies (2.6%), six abscesses occurred following 67 laparoscopic appendectomies (9.0%), and the remaining two abscesses occurred following 36 converted cases (5.6%). For perforated appendicitis, however, there was a statistically significant increase in the rate of abscess formation following laparoscopic appendectomy compared to conventional open appendectomy (9.0% vs. 2.6%,P=0.015). There was no significant difference in the rate of abscess formation between open vs. converted cases or between laparoscopic vs. converted cases. A comparison of the length of the postoperative hospital stay showed no significant difference between open and laparoscopic appendectomy for perforated appendicitis (6.1 days vs. 5.9 days). Laparoscopic appendectomy for perforated appendicitis is associated with a higher rate of postoperative intra-abdominal abscess formation without the benefit of a shortened hospital stay. Given these findings, laparoscopic appendectomy is not recommended in patients with perforated appendicitis.

Variations in treatment of rectal cancer

PURPOSE: Surgical options for the treatment of rectal cancer may involve sphincter-sparing procedures (SSP) or abdominoperineal resection (APR). We sought to examine variations in the surgical treatment of rectal cancer for a large, well-defined patient population and specifically to determine if differences exist in management and survival based on hospital type and surgical caseload. METHODS: The Cancer Surveillance Program database for Los Angeles County was used to retrospectively retrieve data on all patients who underwent SSP or APR for rectal adenocarcinoma between 1988 and 1992. RESULTS: A total of 2,006 patients with adenocarcinoma of the rectum underwent SSP or APR during the study period. Overall, 55 percent underwent SSP, and the remaining 45 percent underwent APR. Use of SSP remained relatively constant for each year of the five-year period. Substantial variability was seen in the use of SSP at various hospital types. For localized disease, this varied from as low as 52 percent at teaching hospitals to as high as 78 percent at hospitals approved by the American College of Surgeons (P=0.067). To examine the role of caseload experience, hospitals were divided into those completing an average of five or fewer rectal cancer cases per yearvs.those completing an average of more than five cases per year. For localized disease, hospitals with higher caseloads performed SSP in significantly more cases, 69vs.63 percent (P=0.049). Survival was seen to be significantly improved for patients operated on at hospitals with higher caseloads, in cases of both localized and regional diseases (P<0.001). CONCLUSION: Surgical choices in the treatment of rectal cancer may vary widely, even in a well-defined geographic region. Although the reasons for this variability are multifactorial, hospital environment and surgical caseload experience seem to have a significant role in the choice of surgical procedure and on survival.

Use of brachytherapy in management of locally recurrent rectal cancer

PURPOSE: Locally recurrent rectal cancer is associated with poor quality of life and has justified aggressive surgical and adjuvant approaches to control the disease. This study was designed to evaluate if the use of brachytherapy in association with wide surgical excision (debulking operation) can offer reasonable palliation for patients with locally recurrent rectal cancer. MATERIALS AND METHODS: Patients with biopsy-proven locally recurrent rectal cancer who were not candidates for intraoperative radiation therapy and who were previously considered as having unresectable tumors were included in the study and were followed-up from May 1981 to November 1990. All of them had undergone laparotomy and had either radical or debulking surgical resection performed. At the same time, brachytherapy was used with temporary or permanent implant of seeds of iridium-192 or iodine-125. RESULTS: Thirty patients were included. Patients ranged in age from 28 to 74 years, and 16 patients were female. No mortality was observed, and morbidity was low (small-bowel obstruction (1 patient), intestinal fistula (1 patient), and urinary fistula (1 patient). Histologic examination of the specimen showed gross residual disease in 67 percent of patients and microscopic disease in 25 percent of patients. Long-term follow-up was possible in 28 patients. Mean follow-up and local control were, respectively, 26.5 months and 37.5 percent for gross residual disease and 34 months and 66 percent for microscopic residual disease. Eighteen patients (64 percent) had locally recurrent rectal cancer under control at the time of the last follow-up, with seven patients (25 percent) having no evidence of local or distant recurrence. CONCLUSION: This is the first report of brachytherapy for locally recurrent rectal cancer. This appears to offer a therapeutic alternative to patients who are not candidates for intraoperative radiation therapy. Surgical morbidity and mortality are acceptable. Local control in 18 patients (64 percent) is comparable with intraoperative radiation therapy or more morbid surgical alternatives. Cancer-related deaths are most often related to disseminated disease, which suggests the need for systemic therapy in addition to brachytherapy.

Gradient of pressure and time between proximal anal canal and high-pressure zone during internal anal sphincter relaxation: Its role in the fecal continence mechanism

PURPOSE: The normal response to rectal distention is a relaxation of the proximal anal canal (PAC). We hypothesized that this mechanism would require a gradient of pressure and time to preserve continence. METHODS: Sixteen volunteers (10 male), mean age, 41.5 (range, 24–60) years, were studied using an eight port axial catheter with a compliant balloon at its tip. Relaxation was induced by a small volume of rectal distention (15–30 ml of air) and was recorded until recovery of resting anal pressure (RAP). Duration of relaxation was measured until recovery of RAP. Amplitude of relaxation was determined between RAP before rectal distention (RAP-BR) and pressure at the point of maximum relaxation (RAP-PMR). Gradient of pressure was determined by comparing RAP-PMR in the high-pressure zone (HPZ) and PAC. Contraction in the distal anal canal was interpreted as external anal sphincter contraction (EASC) and was compared with RAP-PMR in the HPZ. RESULTS: Relaxation was significantly greater in PAC than in HPZ (50vs. 36 percent;P=0.001). RAP-PMR was significantly higher in HPZ than in PAC (30.7vs. 12.6 mmHg;P= 0.001). EASC was observed in six patients and did not show significant difference with RAP-PMR in HPZ (39.7vs. 36.3 mmHg; not significant). Relaxation began at the same time in all levels but lasted significantly longer in PAC compared with HPZ (13.5vs. 9.4 sec;P=0.003). CONCLUSION: Anal relaxation induced by small volume rectal distention involves a gradient in the pressure and time of relaxation between PAC and the HPZ.

Xanthogranulomatous cystitis as a cause of elevated carcinoembryonic antigen mimicking recurrent colorectal cancer: Report of a case

We report a case of xanthogranulomatous cystitis that developed in a patient with a history of colon cancer. While undergoing adjuvant chemotherapy with fluorouracil and levamisole, rising carcinoembryonic antigen (CEA) levels and the appearance of a pelvic mass, suspicious for recurrent cancer, were identified. Exploratory laparotomy demonstrated the presence of a benign condition of the bladder, xanthogranulomatous cystitis, which was resected by partial cystectomy. CEA levels have normalized. This is the first reported case of xanthogranulomatous cystitis producing an elevated CEA level.

Basal and meal-stimulated colonic absorption

PURPOSE: Few quantitative experiments evaluating colonic absorption of water and electrolytes have been performed using an awake, conscious animal model. The purpose of these experiments was to develop this type of model and evaluate both basal and meal-stimulated colonic absorption of water and electrolytes. METHODS: Canine Thiry-Vella fistulas were created using a 20 cm segment of distal colon under general anesthesia. Colonic absorption studies were performed using infusion of the Thiry-Vella fistulas with a buffer solution containing [14C]polyethylene glycol. Electrolyte analysis and concentration of radioactivity in the effluent were obtained and used to calculate the net flux of water, sodium, and chloride. Each study consisted of an one-hour basal period and a three-hour experimental period divided into two groups. Group 1 received no meal. Group 2 orally ingested a mixed meal at the completion of the basal hour. RESULTS: In the basal state, water and electrolytes are absorbed from the distal colon at a steady and constant rate. An orally ingested meal produces a statistically significant increase in the rate of absorption, independent of direct colonic luminal contact with the nutrients of the meal given. CONCLUSIONS: These studies demonstrate anin vivoquantitative and qualitative measure of mammalian colonic water and electrolyte absorption. An increase in absorption rate occurs in response to a meal that is probably the result of an unidentified neural or humoral signal.

Level of highest mean resting pressure segment in the anal canal : A quantitative assessment of anal sphincter function

PURPOSE: Even with development of new technologies, the mechanism of fecal continence is still not completely understood. This study evaluates the relative position of the highest mean resting pressure segment (HMRP) in the anal canal and its correlation with function in incontinent patients and in controls. METHODS: Sixteen incontinent patients (mean age, 47.1±13.9 (range, 18–63) years; 12 female) and 16 controls (mean age, 35.4±8.7 (range, 24–58) years; 12 female) were studied using a water-perfused eight-port radial catheter computer-assisted vectormanometry. Position of the HMRP was analyzed in relation to the anal verge (D1) and to the proximal functional border of the anal canal (D2). RESULTS: Controls had HMRP located more distally in the anal canal, because D2was significantly higher than D1(mean, 3.45±0.75vs.1.81±0.63 cm;P= 0.001). For incontinent patients, D1and D2were similar (mean, 1.86±0.75vs.2.08±1.11 cm; not significant). Comparison of the relative position of the HMRP between patients and controls showed a more proximal location for incontinent patients than controls (mean, 49.1±12.1 percentvs.35.4±10.2 percent;P=0.002). CONCLUSIONS: Position of the HMRP is significantly more proximal for incontinent patients than for controls, and measurement of the distance from the anal verge to the HMRP in relation to the full length of the anal canal may represent another way to quantitatively assess anal sphincter function.