A metastatic colon cancer model using nonoperative transanal rectal injection.

BACKGROUND: This study aimed to develop a noninvasive orthotopic model for metastasis of colon and rectal cancer using a transanal approach. Currently, the most accurate orthotopic representation of metastatic human colon cancer is via a cecal injection. The transanal model allows for further examination of systemic immune responses, tumor take, and onset of metastasis without prior surgical intervention. METHODS: For this study, 60 Balb/c mice were anesthetized and subjected to gentle anal dilation using blunt-tipped forceps at the anal opening. Murine colon cancer parental CT26 or luciferase-labeled CT26 (CT26-luc) cells were injected submucosally into the distal posterior rectum (30 CT26 and 30 CT26 injections) at concentrations of 2.5 x 10(4), 1 x 10(5), and 1 x 10(6) in a volume of 50 microl. Tumor growth and metastatic development was monitored at 5-day intervals for 50 days. All the remaining mice were killed on postinjection day 50. RESULTS: The optimal concentration for metastasis and survival of the mice was 2.5 x 10(4) cells. Higher concentrations of cells yielded higher mortality but did not result in metastasis. The overall success of tumor growth in both experiments using the transanal rectal injection was 65%. Histology showed that all tumors were poorly differentiated adenocarcinomas. Two mice (3.3%) from the 2.5 x 10(4) CT26-luc group showed metastatic colonic adenocarcinoma to the liver on postinjection day 50. CONCLUSION: Transanal rectal injection of colon cancer cells offers a nonoperative orthotopic murine model for colon cancer that may lead to the development of metastasis. By using an orthotopic model, more aspects of metastatic colon cancer can be evaluated without the influence of a previous abdominal incision. These results warrant more investigation.

Stapled transanal rectal resection vs. transvaginal rectocele repair for treatment of obstructive defecation syndrome.

PURPOSE: Stapled transanal rectal resection has been introduced as a new technology for the management of obstructive defecation syndrome. In this study we observed the clinical outcomes for stapled transanal rectal resection as compared with transvaginal rectocele repair for obstructive defecation syndrome. METHODS: This study is a retrospective review of patients who received transvaginal rectocele repair for obstructive defecation syndrome from June 1997 to February 2002 as compared with patients who received stapled transanal rectal resection from June 2005 to August 2007. The clinical outcomes observed were operative time, estimated blood loss, length of stay, complication rate, procedure failure rate, recurrence rate, time to recurrence, and dyspareunia rate. RESULTS: Thirty-seven patients had transvaginal rectocele repair for management of obstructive defecation syndrome, and 36 patients had stapled transanal rectal resection. There was no difference in the age of patients receiving either procedure (transvaginal rectocele repair, 57.92 years old; stapled transanal rectal resection, 53.19 years old; P = 0.1096). Evaluation of the clinical outcomes showed that transvaginal rectocele repair had a longer operative time (transvaginal rectocele repair, 85 minutes; stapled transanal rectal resection, 52 minutes; P = or<0.0001), greater estimated blood loss (transvaginal rectocele repair, 108 ml; stapled transanal rectal resection, 43 ml; P = 0.0015), and a lower complication rate (transvaginal rectocele repair, 18.9 percent; stapled transanal rectal resection, 61.1 percent; P = 0.0001). CONCLUSION: The stapled transanal rectal resection procedure can be done with shorter operative times and less blood loss than transvaginal rectocele repair, however, it has a higher complication rate.

The gap in laparoscopic colorectal experience between colon and rectal and general surgery residency training programs.

PURPOSE: In this article, we review the laparoscopic experience of general surgery and colorectal residency training programs in the United States during the past 5 and 12 years, respectively. The purpose of this study was to determine whether an adequate experience was being provided, and at what level of training, to safely and effectively perform advanced laparoscopy. METHODS: General Surgery Operative Reports from the training years 2000 to 2004 were obtained from the Accreditation Council for Graduate Medical Education. Similarly, colorectal operative performance logs from the training years 1994 to 2005 were obtained from the American Board of Colon and Rectal Surgery. RESULTS: From 2000 to 2004, basic and advanced laparoscopic cases (as designated by the Accreditation Council for Graduate Medical Education) have increased from 10.1 to 12.2 percent and 2.1 to 3.7 percent, respectively. Within this period, the number of laparoscopic colon cases/resident/career has increased from 1.8 to 4.6. The percentage of cases performed laparoscopically increased from 3.9 to 22.5 percent from 1993-1994 to 2004-2005 training years. From 1993 to 2001, the average number of laparoscopic cases/resident increased from 6.3 to 16.1. In 2004, the average number of cases/resident increased to 45.3. Of this number, 30 were colon, 9.4 were rectal, and the remaining 5.9 were miscellaneous colorectal procedures. CONCLUSIONS: Learning curves for laparoscopic colectomy are reported in the range of 20 to 60 cases. Based on the most recent data reviewed, colon and rectal resident experience is tending toward this threshold. Recent general surgery graduates may be lacking the appropriate volume to reach proficiency in laparoscopic colorectal surgery.

A pitfall of protracted surgery in the lithotomy Position: lower extremity compartment syndrome.

Although the lithotomy position is frequently used in urologic, gynecologic, and colorectal surgery, the potentially devastating complication of lower extremity compartment syndrome is not widely recognized. The authors report a 50-year-old woman who underwent 8 hours of colorectal surgery in the lithotomy position. After surgery she complained of bilateral calf pain and was noted to have episodes of ventricular tachycardia. After emergency dialysis for hyperkalemia, she required bilateral four-compartment calf fasciotomy. Prevention of compartment syndrome and its sequelae, when using the lithotomy position, requires minimizing the duration of time in lithotomy. If protracted surgery in lithotomy is necessary, the patient should be carefully monitored for compartment syndrome postoperatively. Urgent four-compartment fasciotomy is the treatment of choice if a compartment syndrome is clinically suspected.

IUD removal with colonoscopy: a case report.

BACKGROUND: Intrauterine device (IUD) perforation of the bowel is uncommon. Although IUD perforation may be asymptomatic, the most common complaint is unexplained abdominal pain. CASE: A case of IUD perforation of the large bowel was diagnosed 7 years after insertion. The patient presented with unexplained lower abdominal pain diagnosed initially as pelvic inflammatory disease. Laparoscopy revealed that the IUD was embedded deeply in the rectum. Bowel preparation and intravenous antibiotics followed by colonoscopy using a grasping snare resulted in successful IUD removal. CONCLUSION: Patients presenting with IUDs embedded in the large bowel may benefit from attempted removal using colonoscopy rather than laparotomy. Bowel preparation, intravenous antibiotics and pos-textraction evaluation to rule out perforation may be prudent.

Prospective comparison of laparoscopic vs. open resections for colorectal adenocarcinoma over a ten-year period.

PURPOSE: The aim of this study was to define the long-term oncologic outcomes of laparoscopic resections for colorectal cancer. METHODS: We analyzed our experience via a prospective, nonrandomized, longitudinal cohort study. The period of study extended from April 1991 to May 2001. Laparoscopic resection was offered selectively in the absence of a large mass, invasion into abdominal wall or adjacent organs, and multiple prior abdominal operations. Every laparoscopic resection performed with curative intent for adenocarcinoma was included. Twenty percent of patients whose procedures were converted to open resection were included in the laparoscopic-resection group because of intention to treat. Oncologic outcome measures of this group were compared with a computerized, case-matched, open-resection group, the case-matching variables being age, gender, site of primary tumor (colon vs. rectum), and TNM stage. The laparoscopic-resection group was followed up prospectively, and data were updated regularly. The follow-up techniques consisted of a combination of office visits, telephone calls, and the United States Social Security Death Index database. RESULTS: The laparoscopic-resection group consisted of 172 patients with a mean age of 67 (range, 27-85) years. The open-resection group consisted of 172 patients with a mean age of 69 (range, 30-90) years. Mean follow-up was 52 (range, 3-128) months. Complete (100 percent) follow-up data were available. The TNM stage distribution was 63 Stage I (37 percent), 51 Stage II (30 percent), 47 Stage III (27 percent), and 11 Stage IV (6 percent) tumors for the laparoscopic-resection group and 65 Stage I (38 percent), 48 Stage II (28 percent), 51 Stage III (29 percent), and 8 Stage IV (5 percent) tumors for patients in the open-resection group (P = 0.75, not significant). Thirty-day mortality was 1.2 percent (2 deaths) in the laparoscopic-resection group and 2.4 percent (4 deaths) in the open-resection group (P > 0.05, not significant). Early and late complication incidences were comparable. Local recurrence was observed in three patients (1.7 percent) in the laparoscopic resection group with the primary tumor in the colon and in three patients (1.7 percent) with the primary tumor in the rectum, for a total incidence of local recurrence in the laparoscopy group of 3.5 percent (6 patients). In the open-resection group, local recurrence was observed in two patients (1.2 percent) among those with primary tumor site in the colon and in three patients (1.7 percent) in the group with primary tumor in the rectum, for a total incidence of local recurrence in the open-resection group of 2.9 percent (5 patients). One of the local recurrences in the laparoscopy group occurred in the port/extraction site, for an incidence of 0.6 percent. Metastasis occurred in 18 patients (10.5 percent) in the open group and in 21 (12.2 percent) in the laparoscopy group. Stage-for-stage overall five-year survival rates were similar in the two groups. The Kaplan-Meier statistical analysis performed for colonic vs. rectal primary adenocarcinoma confirmed that TNM stage for stage-overall survival was similar in the laparoscopic and open-resection groups (log-rank P = 0.22). CONCLUSIONS: Notwithstanding the drawbacks of a nonrandomized study, no adverse long-term oncologic outcomes of laparoscopic resections for colorectal cancer were observed in a single center's experience during a ten-year period.