Long-term outcomes after intersphincteric resection for low-lying rectal cancer.

BACKGROUND: As an anus-preserving surgery for very low rectal cancer, intersphincteric resection (ISR), has advanced markedly over the last 20 years. We investigated long-term oncologic, functional, and quality of life (QOL) outcomes after ISR with or without partial external sphincter resection (PESR). METHODS: A series of 199 patients underwent curative ISR with or without PESR between 2000 and 2008, with 49 receiving preoperative chemoradiotherapy (CRT group) and 150 undergoing surgery first (surgery group). Overall survival (OS), disease-free survival (DFS), and local relapse-free survival (LFS) rates were calculated using Kaplan-Meier methods. Functional outcomes were assessed using the Wexner incontinence score. QOL was investigated using the Short-Form 36 questionnaire (SF-36) and modified fecal incontinence quality of life (mFIQL) scale. RESULTS: After a median follow-up of 78 months (range 12-164 months), estimated 7-year OS, DFS, and LFS rates were 78, 67, and 80 %, respectively. LFS was better in the CRT group than in the surgery group (p = 0.045). Patients with PESR or positive circumferential resection margins showed significantly worse survival. The median Wexner incontinence score at >5 years was 8 in the surgery group and 10 in the CRT group (p = 0.01). QOL was improved in all physical and mental subscales of the SF-36 at >5 years. Although the mFIQL showed a relatively good score in all groups at >5 years, a significant difference existed between the CRT and surgery groups (p = 0.008). CONCLUSIONS: With long-term follow-up, oncologic, functional, and QOL results after ISR appear acceptable, although CRT is associated with disturbance.

Effectiveness of a transanal tube for the prevention of anastomotic leakage after rectal cancer surgery.

AIM: We evaluated the effectiveness and safety of a transanal tube placed for the prevention of anastomotic leakage after rectal surgery. METHODS: Between 2007 and 2011, a total of 243 patients underwent anterior resection using the double stapling technique for rectal cancer at our institution. We excluded 67 patients with diverting stoma and divided the remaining patients into two groups: patients who did not receive a transanal tube and diverting stoma (n = 140; control group) and those who received a transanal tube (n = 36). We compared the rate of anastomotic leakage, evaluated the complications associated with the transanal tube, and analyzed the risk factors for anastomotic leakage. RESULTS: The following perioperative parameters were significantly different between the two groups as follows (control group vs. transanal tube group): diabetes mellitus (8 [22 %] vs. 12 [8.5 %] patients, respectively; p = 0.03), surgical duration (262 ± 54.1 min [171-457] vs. 233 ± 61.7 min [126-430], respectively; p < 0.01). The postoperative anastomosis leakage appeared significantly different between the two groups (1 [2.7 %] vs. 22 [15.7 %] patients, respectively; p = 0.04). Anastomotic leakage was significantly associated with the distance between the anastomosis line and the anal verge (odds ratio [OR] 8.58; 95 % confidence interval [CI] 1.53-48.0; p = 0.01) and non-use of a transanal tube (OR 11.1; 95 % CI 1.04-118; p = 0.04) in both univariate and multivariate analyses. CONCLUSIONS: Placement of a transanal tube is effective in decreasing the rate of anastomotic leakage after anterior resection using the double stapling technique. However, complications associated with a transanal tube should be carefully considered.

Predictors for early recurrence after hepatectomy for initially unresectable colorectal liver metastasis.

BACKGROUND: Early recurrence correlates with poor survival following various cancer surgeries and puts considerable stress on patients both physically and mentally. This retrospective study investigated the predictive factors for early recurrence after surgical resection for initially unresectable colorectal liver metastasis to elucidate indications for conversion strategies. METHODS: We retrospectively studied 46 patients who underwent hepatectomy after chemotherapy for initially unresectable colorectal liver metastasis from 1997 to 2010. RESULTS: Recurrences occurred within 6 months after hepatectomy in 13 patients (37 %). The median survival time of 21.2 months and the 5-year survival rate of 0 % after hepatectomy in patients with recurrence within 6 months were significantly worse than those in patients with recurrence more than 6 months after hepatectomy. Recurrence in less than 6 months was significantly correlated with impossibility of anticancer therapy for recurrence after hepatectomy (p = 0.01). Eight or more hepatic tumors after chemotherapy were the only predictor of recurrence within 6 months (p = 0.01; odds ratio 9.6; 95 % confidence interval 1.5-60.6). CONCLUSION: Recurrence within 6 months was significantly correlated with a poorer outcome following surgery for initially unresectable colorectal liver metastasis. Surgical indication for initially unresectable colorectal liver metastasis with eight or more hepatic tumors after chemotherapy should be considered carefully in the light of mental and physical status, co-morbidity, and alternative treatment plans.

Efficacy of the predicted operation time (POT) strategy for synchronous colorectal liver metastasis (SCLM): feasibility study for staged resection in patients with a long POT.

BACKGROUND: The optimal surgical strategy for resectable synchronous colorectal liver metastases (SCLM), whether simultaneous or staged resections, still remains obscure. The aim of this study was to assess the efficacy of the predicted operation time (POT) strategy, which recommends staged resections in case of POT ≥6 h, otherwise selecting simultaneous resection. METHODS: This was a prospective, nonrandomized, single-institution study. Fifty-nine patients with SCLM underwent tumor resection according to the POT strategy, with patients with a longer POT (≥6 h) undergoing staged resection. Morbidity, overall hospitalization, tumor resection rates, and survival were compared with that of 86 patients who underwent simultaneous resection for SCLM irrespective of POT from 1992 to 2004. RESULTS: The former simultaneous and the latter POT strategy groups were similar in terms of patient and tumor demographics as well as surgical procedures. Of the 59 POT group patients, 26 patients (44 %) experienced 40 postoperative complications. Comparing the surgical results of simultaneous resection from 1992 to 2004 and those of resection according to the POT strategy, morbidity (64 vs. 44 %, p = 0.02), frequency of anastomotic leakage (21 vs. 5 %, p < 0.01), and length of hospital stay (27 vs. 18 days, p < 0.01) were significantly lower in the latter group, while tumor resection rates (85 vs. 87 %, p = 0.77) were not different. CONCLUSIONS: The POT strategy is effective in reducing the morbidity in SCLM patients by selecting staged resections in the high-morbidity-risk group without adverse effects on oncologic outcome.

Rectoseminal vesicle fistula as a rare complication after low anterior resection: a report of three cases.

A rectoseminal vesicle fistula is a rare complication after a low anterior resection for rectal cancer, usually developing in the outpatient postoperative period with pneumaturia, fever, scrotal swelling or testicular pain. A diagnostic water-soluble contrast enema, cystography and computed tomography reveal a tract from the rectum to the seminal vesicle. Anastomotic leakage is thought to be partially responsible for the formation of such tracts. This report presents three cases of rectoseminal vesicle fistula, and the presumed course of the disease and optimal treatment options are discussed.

Incidence and predictive factors for pulmonary metastases after curative resection of colon cancer.

PURPOSE: To assess the actuarial incidence of pulmonary metastases as the first site of metastasis after R0 resection of colon cancer and to clarify predictive factors for pulmonary metastases as the first site of metastasis. METHODS: Data for 746 patients who underwent R0 resection for colon cancer from 2000 to 2006 were reviewed. The mean duration of follow-up was 56.9 months. RESULTS: Pulmonary metastases developed in 35 patients. Mean duration from colon surgery to identification of pulmonary metastases was 20.0 months. The overall occurrence rates of 5-year pulmonary metastasis according to Union for International Cancer Control (UICC) stage were 0.6 % (stage I), 2.2 % (stage II), 9.8 % (stage III), and 24.6 % (stage IV), respectively. Surgery for pulmonary metastases was performed first 18 patients (51.4 %), and 16 (88.9 %) of these 18 patients achieved R0 surgery. Multivariate analysis revealed that presence of regional lymph node involvement and preoperative serum carcinoembryonic antigen level (≥5 ng/ml) were significant independent risk factors for pulmonary metastases. Five-year actuarial incidence of pulmonary metastases increased significantly with increased number of risk factors (0 factors, 2.2 %; 1 factor, 6.6 %; 2 factors, 18.4 %). CONCLUSIONS: The present study clearly demonstrated predictive factors for pulmonary metastases after R0 resection of colon cancer. Actuarial incidence of pulmonary metastases was significantly related to the number of risk factors present. The data should facilitate the establishment of novel algorithms for predicting pulmonary metastases after resection of colon cancer, which may lead to the appropriate surveillance strategies after colon surgery.

Laparoscopic surgery for palliative resection of the primary tumor in incurable stage IV colorectal cancer.

BACKGROUND: The purpose of the study was to evaluate the feasibility and efficacy of laparoscopic palliative resection in patients with incurable stage IV colorectal cancer. METHODS: We reviewed 100 patients with incurable stage IV colorectal cancer who underwent palliative resection of the primary tumor between 2002 and 2009 at National Cancer Center Hospital East (NCCHE). Outcomes and postoperative course were compared between patients who underwent open and laparoscopic surgery. RESULTS: Of the 100 patients, 22 were treated with a laparoscopic procedure and 78 underwent an open surgical procedure. There was no difference in the preoperative characteristics of the two groups. In the laparoscopic group, the mean operation time was significantly longer (177 vs. 148 min, p = 0.007) and the amount of blood loss was significantly lower (166 vs. 361 ml, p = 0.002). Postoperative complications occurred in 5 patients (22.7 %) after laparoscopic surgery and in 21 patients (26.9 %) after open surgery, with no significant difference between the two groups. Time to flatus, time to start of food intake, and hospital stay were all shorter after laparoscopic surgery (3.0 vs. 3.8 days, p = 0.003; 3.6 vs. 5.0 days, p < 0.001; and 12.0 vs. 15.0 days, p = 0.005; respectively). Significantly more patients in the laparoscopic group had >15 % lymphocytes on postoperative day 7 (p = 0.049). Overall survival rates were 73.7 and 75.5 % at 1 year after laparoscopic surgery and open surgery, respectively (p = 0.344). CONCLUSIONS: A laparoscopic procedure should be considered for palliative resection of the primary tumor for incurable stage IV colorectal cancer, because the results of this study indicate that the procedure is safe and effective.

Differences in tissue degeneration between preoperative chemotherapy and preoperative chemoradiotherapy for colorectal cancer.

PURPOSE: Preoperative chemoradiotherapy (CRT) for rectal cancer is administered to improve local control, but can also induce severe anal dysfunction after surgery, while preoperative chemotherapy that significantly reduces the primary lesion in rectal cancer has recently been developed. The aim of the study was to examine differences in the effects of preoperative CRT and chemotherapy on tissue degeneration of patients with colorectal cancer. METHODS: The subjects were 91 patients, including 68 with rectal cancer who underwent internal sphincteric resection with (n = 47, CRT group) or without (n = 21, control group) preoperative CRT, and 23 with colorectal cancer who received preoperative FOLFOX treatment. Peripheral nerve degeneration was evaluated histopathologically using H&E-stained sections, based on karyopyknosis, disparity of the nucleus, denucleation, vacuolar or acidophilic degeneration of the cytoplasm, and adventitial neuronal changes. RESULTS: The incidence of neural degeneration was significantly higher in the CRT group than in the control group and FOLFOX group. There were no differences in any items of neural degeneration between the FOLFOX and control groups. CONCLUSION: CRT induced marked neural degeneration around the rectal tumor. FOLFOX treatment produced mild neural degeneration similar to that in the control group.

Postoperative chylous ascites after colorectal cancer surgery.

PURPOSE: To evaluate the diagnosis, epidemiology, risk factors, and treatment of chylous ascites after colorectal cancer surgery. METHODS: Among 907 patients who underwent colorectal cancer resection at our institution between 2006 and 2009, chylous ascites developed in 9. We analyzed the clinical data for these 9 patients. RESULTS: Five of the nine patients with chylous ascites had undergone right hemicolectomy and seven had undergone D3 lymph node dissection. In all patients, chylous ascites began to develop the day after commencement of oral intake or the next day. Two patients had no change in diet, one was started on a high-protein and low-fat diet, and six were put on intestinal fasting. Drainage tubes were removed within 5 days after treatment in seven patients. The hospital stay was about 2 weeks after surgery and 1 week after treatment. We found that the tumor area, tumors fed by the superior mesenteric artery, and D3 lymph node dissection were significantly associated with chylous ascites. CONCLUSIONS: Chylous ascites after colorectal cancer surgery occurred at an incidence of 1.0%, but was significantly more frequent after surgery for tumors fed by the superior mesenteric artery and after D3 lymph node dissection. Conservative treatment was effective in all cases.

Association between anal function and therapeutic effect after preoperative chemoradiotherapy followed by intersphincteric resection.

BACKGROUND/AIMS: Preoperative chemoradiotherapy (CRT) for rectal cancer improves local control, but can also induce severe anal dysfunction after surgery. The goal of the study was to assess the relationship of the therapeutic effect of CRT with anal function and prognosis after intersphincteric resection (ISR). METHODS: The subjects were 37 patients with lower rectal cancer who underwent ISR with preoperative CRT. The rectal cancer regression grade (RCRG) was quantified based on histologic features of surgical specimens. The relationships of RCRG with anal function (assessed by questionnaire) and incontinence (Wexner score) were examined at 12 months after surgery. RESULTS: The median Wexner scores at 12 months after stoma closure in RCRG1, -2, and -3 cases were 18.0, 7.5, and 4.5, respectively, and anal function differed significantly among these groups (p = 0.001). Four cases had local recurrence, but 5-year local recurrence rates did not differ significantly among the groups. The 5-year disease-free survival rates were 88.9, 50.8, and 50.0% and the 5-year overall survival rates were 100, 77.3, and 66.7% in RCRG1, -2, and -3 cases, respectively, with no significant differences among the groups. CONCLUSION: Postoperative anal function is decreased when the effect of preoperative CRT is strong in patients treated with ISR.

Surgical management of small bowel metastases from primary carcinoma of the lung.

PURPOSE: To investigate the treatment and outcomes in a series of seven cases of small bowel metastases from lung cancer. METHODS: A total of 4114 patients with lung cancer were referred to this institution from 1995 to 2005. Seven (0.17%) developed symptomatic small bowel metastasis and were treated surgically. The clinical, radiological, and pathological records were reviewed. RESULTS: Small bowel metastases were diagnosed from 0 to 31 months (mean 11.5 months) after the diagnosis of lung cancer. The clinical symptoms at presentation were acute peritonitis in two patients and abdominal pain in five. Small bowel metastasis was suspected on abdominal X-ray in three cases, computed tomography in two, small bowel radiography in one, and endogastroduodenoscopy in one. All patients underwent surgery and there were no perioperative deaths. Intestinal resection was performed in five cases and a bypass in two. A small bowel metastasis was found in the ileum in four patients. The mean survival period was 7.7 months after surgery. One patient lived for 22 months after bowel resection. Oral intake was possible 1 month after surgery in six cases. CONCLUSION: Surgical management should be considered as palliative treatment in patients with a bowel obstruction or peritonitis caused by primary lung cancer.

The association between anal function and neural degeneration after preoperative chemoradiotherapy followed by intersphincteric resection.

BACKGROUND: Preoperative chemoradiotherapy for rectal cancer is administered to improve local control, but it can also induce severe anal dysfunction after surgery. OBJECTIVE: The goals of the study were to assess the influence of preoperative chemoradiotherapy on pathological findings and to examine the correlation of these findings with the cause of severe anal dysfunction after intersphincteric resection. DESIGN: Peripheral nerve degeneration was evaluated histopathologically with the use of hematoxylin and eosin-stained sections of surgical specimens after intersphincteric resection, based on karyopyknosis, vacuolar degeneration, acidophilic degeneration of cytoplasm, denucleation, and adventitial neuronal changes. Each item was scored to quantify the level of neural degeneration, and the relationship between degeneration and anal function was examined at 12 months after closure of the stoma. Anal function was assessed by questionnaire, and incontinence was evaluated based on the Wexner score. SETTING: This study was conducted at the National Cancer Center Hospital East from 2001 to 2006. PATIENTS: The subjects were 68 patients with lower rectal cancer who underwent intersphincteric resection with (n = 47) or without (n = 21) preoperative chemoradiotherapy. MAIN OUTCOME MEASURES: The findings in the 2 groups were compared to clarify the association between the degree of histological degeneration and postoperative anal function. RESULTS: Neural degeneration was significantly higher in the chemoradiotherapy group, and the neural degeneration and Wexner scores had a significant correlation (P = .003, r = 0.477). CONCLUSION: Preoperative chemoradiotherapy induced marked neural degeneration around the rectal tumor. The significant correlation between the degeneration score and postoperative anal function suggests that this score may be a useful marker to predict the influence of preoperative chemoradiotherapy on anal function after surgery.

[Sphincter-saving resection for low rectal cancer].

R0 resection, preservation of the anal sphincter, and local control are considered to be the most important target criteria in rectal cancer surgery. Many efforts have been made in recent years to increase the rate of sphincter preservation by performing pull-through operations, ultra-low anterior resection (U-LAR), and intersphincteric resection (ISR). U-LAR is the standard surgery for patients with lower rectal cancer to preserve anal function. Reconstruction in U-LAR is mainly performed using stapled anastomosis. Although conventional coloanal anastomosis makes it possible to preserve the anal sphincter, the mechanical methods are difficult. In that case, almost all the internal sphincter is preserved. The final options for preserving the sphincter are ISR and external sphincter resection (ESR). Although the internal sphincter is sacrificed partially, subtotally, or totally in ISR, and the external sphincter is resected partially or extensively in ESR, complete or incomplete anal function is maintained. However, the literature is not clear regarding long-term oncologic outcome and anal function after these procedures. The application of these surgical techniques can reduce the rate of abdominoperineal resection in very low rectal cancer. The indications for these procedures must be carefully determined based on tumor site and stage as well as the patient's own preference.

Predictive factors for pulmonary metastases after curative resection of rectal cancer without preoperative chemoradiotherapy.

OBJECTIVE: The aim of this study was to clarify the actuarial incidence of pulmonary metastases and risk factors for pulmonary metastases after curative resection of rectal cancer without preoperative chemoradiotherapy. DESIGN: This study was a retrospective review. PATIENTS: Data for 314 patients who underwent R0 resection for rectal cancer without preoperative chemoradiotherapy from 2000 to 2006 were reviewed. The mean duration of follow-up was 57.0 months. RESULTS: Pulmonary metastases developed in 41 patients. Mean duration from rectal surgery to identification of pulmonary metastases was 21.1 months. Surgery for pulmonary metastases was performed first for 19 patients (46.3%), and all patients achieved R0 surgery. Multivariate analysis revealed that tumor depth (T3 to T4), lymph node ratio (>0.091), and tumor location (anal canal) were significant independent risk factors for pulmonary metastases. Five-year actuarial incidence of pulmonary metastasis increased significantly with increased numbers of risk factors (0 factors, 1.1%; 1 factor, 13.2%; ≥2 factors, 40.1%). In terms of lateral pelvic lymph node involvement, the number of lateral pelvic lymph node involvements (≥4) and the distribution of lateral pelvic lymph node metastases (bilateral) were significant risk factors for pulmonary metastases. CONCLUSIONS: The present study clearly demonstrated predictive factors for pulmonary metastases after R0 resection of rectal cancer without preoperative chemoradiotherapy. Actuarial incidence of pulmonary metastases was significantly related to the number of risk factors present. The data from the present study should facilitate the establishment of novel algorithms for predicting pulmonary metastases after resection of rectal cancer, which may lead to the appropriate surveillance strategies after rectal surgery.

Association between incisional surgical site infection and the type of skin closure after stoma closure.

PURPOSE: This study was performed to investigate the effect of subcuticular sutures on the incidence of incisional surgical site infection (SSI) after closure of a diverting stoma. METHODS: The study was carried out as a retrospective analysis of prospectively collected data from 51 patients who underwent closure of diverting stoma following resections of lower rectal cancer between January 2008 and December 2008. This study attempted to determine whether there was an association between the type of skin closure and the incidence of incisional SSI. Moreover, risk factors for incisional SSI after closure of diverting stoma were identified using a multivariate analysis. RESULTS: An incisional SSI occurred in 12 of the 51 patients (23.5%). The rate of incisional SSI with subcuticular sutures was 11.1% (3/27) in comparison to 37.5% (9/24) with transdermal suture and skin stapler. A subcuticular skin closure was the only favorable factor that was significantly associated with a lower incidence of incisional SSI (odds ratio: 0.19; 95% confidence interval: 0.04-0.92). CONCLUSIONS: A subcuticular skin closure has a protective effect against incisional SSI after closure of diverting stoma. A larger study is necessary to further define the role of subcuticular suture on the prevention of incisional SSI in cases of gastrointestinal surgery.

Male sexual dysfunction after rectal cancer surgery.

PURPOSE: The aims of the study were to determine the extent of male sexual dysfunction after surgical treatment of rectal cancer and to examine the outcome of postoperative treatment with sildenafil. METHODS: A prospective study was performed in patients who underwent attempted curative total mesorectal excision (TME) for low rectal cancers. Sexual function scores were determined by questionnaire preoperatively and at 3 and 12 months postoperatively. Outcomes were examined in patients who were sexually active preoperatively. RESULTS: From 2000 to 2007, 207 patients underwent TME at our institution, of whom 49 (24%) were sexually active preoperatively. Erectile dysfunction and ejaculatory problems were present in 80% and 82%, respectively of the 49 patients at 3 months postoperatively, and in 76% and 67%, respectively at 12 months. Lateral lymph node dissection was a strong risk factor for postoperative sexual dysfunction. The impotency rate was 37% and 47% of patients were unable to ejaculate. Sildenafil was administered to 16 patients who requested the drug during follow-up, and sexual dysfunction was improved in 11 of these patients (69%). CONCLUSION: Sexual dysfunction occurs frequently after rectal cancer treatment and is mainly caused by surgical damage in lateral lymph node dissection. Sildenafil may be effective for the treatment of sexual dysfunction.

Preliminary experience with bladder preservation for lower rectal cancers involving the lower urinary tract.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the feasibility of en bloc colorectal resection combined with radical prostatectomy as an alternative to total pelvic exenteration (TPE) for patients with locally advanced rectal cancer involving the lower urinary tract organs. METHODS: Twenty men with primary rectal cancer clinically involving the lower urinary tract organs underwent extended colorectal resection combined with radical prostatectomy. Data were entered prospectively into a database. Oncological and functional outcomes were analyzed. RESULTS: Anal sphincter-preserving operation (SPO) with radical prostatectomy was performed in 12 patients, abdominoperineal resection with radical prostatectomy in 8, and urinary reconstruction in 16. Morbidity and mortality rates were 35.0% and 0%, respectively. Five-year overall and disease-free survival rates were 83.6% and 42%, respectively. The cumulative 5-year local recurrence rate was 20.0%. All patients with urinary reconstruction achieved good voiding function, and patients with SPO showed acceptable anal function. CONCLUSIONS: For lower rectal cancers involving lower urinary tract, en bloc rectal resection combined with radical prostatectomy appears oncologically acceptable and can reduce the number of TPEs.

Oncologic outcome of intersphincteric resection for very low rectal cancer.

BACKGROUND: In 2000 we launched a prospective program of intersphincteric resection (ISR) for very low rectal cancer. In this study we compared the oncologic outcome of patients who underwent ISR with the outcome of patients who underwent abdominoperineal resection (APR). METHODS: The data of 202 patients with very low rectal cancer who underwent curative ISR (n = 132) or curative APR (n = 70) between 1995 and 2006 were analyzed. Patients were divided into ISR and APR groups. Survival and local recurrence were investigated in both groups. RESULTS: The median follow-up was 40 months in the ISR group and 57 months in the APR group. The 5-year local relapse-free survival rate was 83% in the ISR group and 80% in the APR group (p = 0.364), and the 5-year disease-free survival rate was 69% in the ISR group and 63% in the APR group (p = 0.714). CONCLUSIONS: For very low rectal cancers, ISR appears to be oncologically acceptable and can reduce the number of APRs.

Analysis of clinical factors associated with anal function after intersphincteric resection for very low rectal cancer.

PURPOSE: The purpose of this study was to identify factors that have a negative impact on anal function after intersphincteric resection. METHODS: We evaluated postoperative anal function in 96 patients with very lower rectal cancer who underwent intersphincteric resection by having patients fill out detailed questionnaires at 3, 6, 12, and 24 months after surgery. Univariate and multivariate analysis based on the Wexner incontinence score were used to identify factors associated with poor anal function after intersphincteric resection. RESULTS: The mean Wexner score at 12 months after stoma closure was 10.0. Patients with frequent major soiling showed a Wexner score of >or=16, and this score was used as a cutoff value of poor anal function. In the univariate analysis, poor anal function was significantly associated with a greater extent of excision of the internal sphincter and with preoperative chemoradiotherapy. In the multivariate analysis, preoperative chemoradiotherapy was the only independent factor associated with poor anal function after intersphincteric resection (odds ratio=10.3; 95 percent confidence interval, 2.3-46.3, P < 0.01). CONCLUSIONS: Preoperative chemoradiotherapy was identified as the risk factor with the greatest negative impact on anal function after intersphincteric resection, regardless of extent of excision of the internal sphincter.