Biomedical subjects
R W Beart
Publications and source records attributed to R W Beart.
Laparoscopic Bowel Surgery Registry. Preliminary results.
UNLABELLED: Laparoscopic surgery has evolved rapidly since 1989. The American Society of Colon and Rectal Surgeons, the Society of American Gastrointestinal Endoscopic Surgeons, and the American College of Surgeons Commission on Cancer jointly sponsored a registry to identify as early as possible the patterns of practice and acute complications of laparoscopic colectomy. METHODS: Cases were voluntarily registered by community and academic surgeons. Information was entered in the EPI-5 database. RESULTS: One thousand fifty-six cases were contributed by 118 surgeons; 763 patients were completed laparoscopically. The most common indication for surgery was cancer in 453 patients. The right colon (n = 364) and sigmoid (n = 294) were most frequently resected. Respondents felt adequate cancer resections were performed. Although several unique complications were noted, intraoperative complications were similar in type and frequency to open cases. CONCLUSION: Laparoscopic colorectal surgery can be performed with acceptable complications. It remains unclear if this approach is adequate for long-term management of colon and rectal cancer.
Does peritoneal mobilization increase laparoscopic acidosis?
PURPOSE: It was hypothesized that laparoscopic colon surgery may be associated with increased absorption of CO2 resulting from mobilization of lateral peritoneal reflections. METHODS: Six pigs underwent laparotomy with removal of a measured quadrant of peritoneum before insufflation to 15 mmHg with CO2. Six paired control animals also underwent insufflation with CO2 to 15 mmHg. Measurements of the end-tidal CO2 (PetCO2), arterial blood gas analysis for CO2 (PaCO2), and pH were performed before insufflation, at 5 and 10 minutes following insufflation, then at successive 15-minute intervals for a total of two hours, and 15 minutes following desufflation. No attempt was made to correct the hypercarbia by increasing minute ventilation. RESULTS: PaCO2 reached its maximum level at two hours with values of 70.77 +/- 5.54 mmHg and 64.62 +/- 5.18 mmHg in the peritonectomized and control groups, respectively. PetCO2 also peaked at two hours to 60 +/- 13 mmHg for the study group and 54 +/- 11 mmHg for controls. pH reached its nadir at two hours, falling from a baseline of 7.45 +/- 0.08 to 7.23 +/- 0.09 in the study group, and from 7.42 +/- 0.04 to 7.24 +/- 0.04 in the control group. There were no statistically significant differences between the two groups for any of the parameters measured at each time interval. CONCLUSIONS: The hypothesis that peritonectomy produces greater CO2 absorption during CO2 pneumoperitoneum was disproved under these experimental conditions.
Physiology of ileal pouch-anal anastomosis. Current concepts.
PURPOSE: Increasing experience with ileal pouch-anal anastomosis (IPAA) associated with increasing knowledge about anorectal physiology has lead to a large number of publications. The purpose of this review is to evaluate the current understanding of fecal continence as revealed by the evolution of the ileoanal procedure. METHODS: Review of the literature covering the most important physiologic parameters involved in fecal continence was undertaken. RESULTS: Rectoanal inhibitory reflex is probably absent after IPAA but is preserved when distal anorectal mucosa is spared. Anal resting pressure decreases but is less affected when the internal anal sphincter is less traumatized. Squeeze pressure is not importantly affected, and the importance of reservoir function as a determinant of stool frequency is emphasized. IPAA does not affect the coordination between pouch and anal canal motility in the majority of cases. Normal continence is preserved, even during the night, by preserving a gradient of pressure between the pouch and anal canal. CONCLUSIONS: Physiologic concepts are well established, but controversies about the continence mechanism related to IPAA remain. The IPAA procedure has allowed discrimination of details about the function of multiple structures involved in fecal continence.
Coloanal anastomosis for rectal cancer. Long-term results at the Mayo and Cleveland Clinics.
PURPOSE: This study was designed to determine functional outcomes and rates of survival and recurrence of coloanal anastomosis in rectal cancer patients. METHODS: Between 1981 and 1991, 117 patients underwent coloanal anastomosis. Fifteen percent of the patients had a J-pouch; the rest had a straight coloanal anastomosis. Thirty-eight percent had no diverting stoma. Median distance of the tumor from the anal verge was 6.7 cm. RESULTS: Local recurrence rate was 7 percent. Five-year survival was fully 69 percent. Satisfactory fecal continence was achieved by 78 percent of patients; no J-pouch patient had frequent incontinence. Sixty-two percent of the patients had major (anastomotic leak = 18 percent) or minor complications; complications were not mitigated by a diverting stoma or worsened by adjuvant therapy. CONCLUSION: Although coloanal anastomosis is associated with a high chance of complications, the long-term outcome, in terms of disease-free survival and satisfactory function, is excellent.
Lengthening of the mesentery using the marginal vascular arcade of the right colon as the blood supply to the ileal pouch.
PURPOSE: Creation of a safe ileal pouch requires a tension-free anastomosis. The aim of this study was to evaluate a technical procedure that increases the length of the mesentery while preserving the blood supply to the ileal pouch. HYPOTHESIS: Preservation of the marginal vascular arcade (MVA) of the right colon will allow ligation of more mesenteric vessels and increase the mesenteric length. METHODS: Six fresh cadavers were dissected. Measurement of the apex of the terminal ileum was done in relation to the pubic symphysis. Measurements were taken after 1) complete mobilization of the terminal ileum, right colon, and hepatic flexure; 2) vascular ligation between colon wall and the MVA, preserving the latter from the right branch of the middle colic artery to the ileal branch of the ileocolic artery (ICA); 3) ligation of the distal third of the superior mesenteric artery; 4) ligation of the ICA at its origin; 5) ligation of the right colon artery; and 6) division of the terminal ileal mesentery. RESULTS: This technique enabled complete division of the terminal ileal mesentery, adding a mean additional 3.6 (range, 2.5 - 5.0) cm (36.5 +/- 16.5 percent) in length to the mesentery, compared with superior mesenteric artery, ICA, and right colic artery ligation. CONCLUSION: Patients who have a shorter mesentery and concern of excessive mesenteric tension should have colectomy performed, preserving the MVA from the middle colic artery to the ileal branch of the ICA. The preserved MVA can be a reliable alternative blood supply to the pouch if more mesenteric vessel ligations are necessary.
Indeterminate colitis. Long-term outcome in patients after ileal pouch-anal anastomosis.
UNLABELLED: Uncertainty persists concerning the long-term results of ileal pouch-anal anastomosis performed for indeterminate colitis. PURPOSE: This study was designed to compare functional outcomes of ileal pouch-anal anastomosis in patients with typical chronic ulcerative colitis and indeterminate colitis. METHOD: Seventy-one ileoanal pouch patients were identified with a diagnosis of indeterminate colitis. Mean follow-up was 56 months. Outcomes were compared with 1,232 chronic ulcerative colitis patients after ileal pouch-anal anastomosis. Mean follow-up was 60 months. RESULTS: (mean +/- SD) There was no difference in the frequency of daily bowel movements (indeterminate colitis, 7 +/- 3, vs. chronic ulcerative colitis, 7 +/- 2). Daytime and nighttime incontinence rates were likewise similar. Prevalence of pouchitis was identical (33 percent). However, failure rate was higher in the indeterminate colitis group (indeterminate colitis, 19 percent, vs. chronic ulcerative colitis, 8 percent; (P = 0.03)). CONCLUSIONS: At a mean of nearly five years after surgery, failure appears to occur more frequently in patients with indeterminate colitis than in patients with chronic ulcerative colitis. However, the great majority of indeterminate colitis patients (> 80 percent) have long-term functional results identical to those of patients with chronic ulcerative colitis.
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 surgeon's 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.
Fecal diversion for penetrating colon injuries--still the established treatment.
PURPOSE: An analysis of the existing literature on primary repair of colon injuries was undertaken to determine if there is sufficient evidence that this approach is superior to fecal diversion. METHODS: After a thorough literature search, three prospectively randomized studies comparing primary repair with fecal diversion in the management of colon injuries were identified. A variety of factors were examined, including the number of patients in each study arm, morbidity rates, as well as exclusion criteria. An analysis was performed to determine the number of patients required to establish statistical superiority of one procedure over the other. RESULTS: Pooling of the data contained in the aforementioned reports does not provide sufficient statistical power to support the superiority of primary repair of colon injuries. To demonstrate a 5 percent difference between the two approaches, a prospective, randomized study consisting of 200 patients in each arm is necessary. CONCLUSION: The present literature does not support a statistically valid advantage of primary repair over fecal diversion in the management of traumatic colon injuries.
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 (50 vs. 36 percent; P = 0.001). RAP-PMR was significantly higher in HPZ than in PAC (30.7 vs. 12.6 mmHg; P = 0.001). EASC was observed in six patients and did not show significant difference with RAP-PMR in HPZ (39.7 vs. 36.3 mmHg; not significant). Relaxation began at the same time in all levels but lasted significantly longer in PAC compared with HPZ (13.5 vs. 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.
Role of laparoscopy in colorectal surgery. A prospective evaluation of 200 cases.
PURPOSE: The aim of this study was to prospectively evaluate the role of laparoscopic-assisted surgery in patients presenting for routine colorectal surgical procedures. METHODS: Two hundred consecutive patients were assessed for the possible use of laparoscopic surgery. The decision regarding suitability of the patient for the procedure was made by the operator. For the purpose of analysis, patients were assigned to open, converted, and laparoscopic groups. RESULTS: Ninety-five of 200 patients were considered appropriate for laparoscopic surgery, 62 (65.3 percent) being successfully completed. These completed operations included right colectomy (24/30), sigmoid colectomy (22/36), appendectomy (9/10), anterior resection (3/8), abdominoperineal resection (3/5), and left colectomy (1/2). Complications attributable to laparoscopy were infrequent (6.3 percent) and were not responsible for any deaths. Patients in the laparoscopic group required less analgesia, tolerated oral intake earlier, and were discharged from the hospital earlier than those who were converted or who had open procedures. CONCLUSIONS: Laparoscopic-assisted surgery is safe, effective, and applicable to many of the standard colorectal procedures. Observed benefits include less postoperative pain and shorter hospital stay.
Pouchitis: a clarification.
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Wound and port site recurrence.
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Management and survival of patients with adenocarcinoma of the colon and rectum: a national survey of the Commission on Cancer.
BACKGROUND: The Commission on Cancer (COC) of The American College of Surgeons periodically reviews criteria for evaluation of the care of patients with cancer related to diagnosis, treatment, rehabilitation, and follow-up. The COC annually performs a national survey of practices for several cancer sites. STUDY DESIGN: Data collection forms for carcinoma of the colon and rectum were field-tested and then forwarded to participating hospitals. The study included a long-term survey to permit evaluation of five-year survival rates and a short-term survey to review current practices and time trends. Specific questions were asked concerning disease presentation, preoperative evaluation, surgical treatment, postoperative care, use of adjuvant therapy, and disease status at the last follow-up examination. RESULTS: A total of 39,502 reports from 943 hospitals were analyzed, including 12,682 patients with carcinoma of the colon diagnosed in 1983, 16,527 patients with carcinoma of the colon diagnosed in 1988, 4,597 patients with carcinoma of the rectum diagnosed in 1983; and 5,696 patients with carcinoma of the rectum diagnosed in 1988. Patterns of care, including changes in presentation, diagnostic and therapeutic management, and survival rates, are presented. Specific data showing results for various ethnic groups are also included. CONCLUSIONS: The distribution of cases by anatomic site was consistent with a hypothesis of rightward migration of colon carcinoma. Colon and rectal carcinomas in African-Americans were reported in more advanced stages and with corresponding decreases in survival rates. Some patterns of nonoptimal diagnostic use were noted. The increasing use of sphincter-sparing surgical alternatives for carcinoma of the rectum was evident. Adjuvant therapy was not widely used during this period. This study suggests evolving patterns of evaluation, increased preservation of continence, and improved but varying survival among ethnic groups. It further suggests that survival as measured across these 943 hospitals may be lower than that attained at some individual centers.
Surgical management of Meckel's diverticulum.
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Laparoscopy and colon cancer. Is the port site at risk? A preliminary report.
PURPOSE: To quantify the magnitude of the risk for port/extraction site recurrence of laparoscopically resected colon cancer in a defined study population. METHODS: The data from a prospective laparoscopic bowel surgery registry was used to identify cases of colon cancer that were resected laparoscopically, with a minimum follow-up of 1 year. A questionnaire was sent to the surgeons who performed the procedures. RESULTS: A total of 252 cases were identified from the registry. Questionnaires were returned in 208 of those cases, a response rate of 82.5%. Three cases of port or extraction site recurrence were noted, two of them associated with diffuse peritoneal carcinomatosis. All the patients had a Dukes' stage C tumor at the time of initial surgery. CONCLUSIONS: The incidence of port/extraction site recurrence following laparoscopic colon cancer surgery is low. All the recurrences were in patients with Dukes' stage C tumors, and there was diffuse peritoneal carcinomatosis in two of the three cases, suggesting that port/extraction site recurrence may be attributable to the advanced nature of the disease rather than the laparoscopic technique. Longer follow-up and more cases are required to confirm these findings.
Adequacy of lymphadenectomy in laparoscopic-assisted colectomy for colorectal cancer: a preliminary report.
The hypothesis that the length of bowel and amount of mesentery resected with laparoscopically assisted colectomy are comparable to traditional open techniques was tested by means of a chart review of prospectively collected data of 22 laparoscopically assisted colectomies, 35 open colectomies performed by the same surgeon, and 39 other open colectomies performed at the same institution by other community surgeons. The average length of bowel resected in the laparoscopically assisted group was 21.7 cm, for the traditionally resected group, 31.4 cm, and for the other group, 26.7 cm. No statistically significant differences existed between the three evaluable groups. Although there was a trend toward greater length of bowel resected with the open technique, there was no statistically significant difference in this study. Follow-up at a mean of 24 months after resections shows no abdominal wall recurrences or any unusual patterns of recurrence. It is concluded that laparoscopically assisted colectomy can be performed in select groups to obtain adequate surgical resection for colorectal carcinoma. Further studies to generate larger numbers of patients with longer follow-up to determine the adequacy of resection as well as the comparability of cure rate will be necessary to confirm the findings of this preliminary study.
Multiple hemorrhoidal bandings in a single session.
PURPOSE: The aim of our study was to evaluate the risks of multiple hemorrhoidal bandings in a single session. METHODS: We retrospectively examined all of the patients who had hemorrhoidal bandings from July 1989 to August 1992. RESULTS: Patients with multiple hemorrhoidal banding in a single session when compared with patients with single banding had greater discomfort and pain (29 percent vs. 4.5 percent), but this discomfort was usually manageable with oral analgesia of limited duration. There were also more vasovagal symptoms (5.2 percent vs. 0 percent), local swelling and edema (2.6 percent vs. 0 percent), and urinary hesitancy and frequency (12.3 percent vs. 0 percent) in the multiple-banded patients. No major complication such as massive delayed bleeding and perineal or pelvic sepsis was noted. CONCLUSION: Most patients tolerated multiple hemorrhoidal banding in a single session with acceptably low complications. Multiple banding in a single session is a safe and cost-effective alternative.