Current controversies in colon and rectal cancer

Colon and rectal cancer is one of the leading causes of cancer death worldwide. Several areas of uncertainty remain in the screening and treatment of this disease, even though significant advances have already led to decreased rates of incidence and mortality over the last several decades. This review addresses some of the current controversies in screening for and the treatment of colorectal cancer, including specifically looking at issues related to screening modalities, local versus radical resections, protocols for adjuvant therapy and the treatment of stage IV disease.

Familial adenomatous polyposis and extracolonic cancer

Our purpose is to focus attention on the cancer family history, coupled with an understanding of the natural history and extracolonic tumor spectrum of familial adenomatous polyposis (FAP), through a family study. This family report provides an example of how colorectal cancer (CRC) can be prevented by knowledgeable gastroenterologists and colorectal surgeons who educate and compassionately counsel members of high-risk families so that their compliance with diagnostic screening and, ultimately, with protection through prophylactic colectomy, is achieved. A working pedigree of this extended family was constructed through interviews with the proband, followed by questionnaires sent to all primary and secondary relatives. Appropriately signed permission forms enabled us to secure pertinent medical and pathology records in order to ensure accuracy of historical information. Integral extracolonic tumors included medulloblastoma, papillary thyroid carcinoma, hepatoblastoma, and desmoid tumors. We conclude that, due in part to improved longevity as a result of being spared CRC, several family members have developed certain FAP integral extracolonic cancers.

A prospective evaluation of the value of anorectal physiology in the management of fecal incontinence

PURPOSE

This study was designed to determine whether anorectal physiology testing significantly altered patient management in the setting of fecal incontinence.

METHODS

Patients referred to the anorectal physiology laboratory for evaluation of fecal incontinence were prospectively interviewed and examined by a colon and rectal surgeon. A decision to treat either medically or surgically was reached. The patients underwent physiologic testing with transanal ultrasound, pudendal nerve terminal motor latency, and anorectal manometry. A panel of board-certified colon and rectal surgeons then reviewed the history and physical examination, as well as the anorectal physiology tests, of each patient and reached a consensus on management. Management plans before and after physiologic evaluation were compared.

RESULTS

Ninety patients (6 males) were entered into the study. The patients were divided in two groups: those with pretest medical management plans (n = 45) and those with pretest surgical management plans (n = 45). A change in management was noted in nine patients (10 percent). In the medical management group, the management changed from medical to surgical therapy in five patients. Transanal ultrasound detected anal sphincter defects in all patients who changed from medical to surgical management but in only 10 percent of those who remained under medical management (P = 0.0001). In the surgical management group, three patients (7 percent) changed from surgical to medical therapy and one patient (2 percent) changed from sphincteroplasty to neosphincter. Transanal ultrasound detected a limited anal sphincter defect in one patient (33 percent) who changed from surgical to medical management and a significant defect in all 41 patients (100 percent) who remained under surgical management (P = 0.003).

CONCLUSIONS

Anorectal physiology testing is useful in the evaluation of patients with fecal incontinence. Without the information obtained from physiologic testing, 11 percent of patients who may have benefited from surgery would not have been given this option, and 7 percent of patients could have potentially undergone unnecessary surgery. Transanal ultrasound is the study most likely to change a patient's management plan.

Mouth to pouch transit after restorative proctocolectomy: hydrogen breath analysis correlates with scintigraphy

OBJECTIVES

Fast intestinal transit may be responsible for slow adaptation and unacceptable steady-state function after restorative proctocolectomy. Investigation of GI transit time may be valuable in such a setting. We hypothesized that postprandial hydrogen breath tests may yield transit data that correlate with technetium-labeled meal scintigrams.

METHODS

This study compared intestinal transit after a lactulose and bean meal via the breath hydrogen and scintigraphy methods in 21 ileoanal pouch subjects. The meal consisted of baked beans (425 g), 30 ml (20 g) lactulose syrup, 1 mCi 99mtechnetium sulfur colloid in finely chopped liver and 170 ml tap water. The meal contained 120 Kcal (70% carbohydrate, 18% protein and 12% fat).

RESULTS

Of 21 pouch subjects, 11 (53%) had breath tests and scintigraphy transit studies that differed by 5-21 min. Three of 21 (14%) scintigraphy mouth to pouch transit times were faster than breath test transits by 43-107 min. Seven of 21 (33%) subjects did not have breath test peaks >10 ppm. Mouth to pouch transit for breath hydrogen (104+/-16 min) and scintigraphy (98+/-7 min) tests had significant correlation (r = 0.96, p < 0.0001) among subjects with alveolar hydrogen peaks and accurate scintigrams (n = 11). Scintigrams were five times more expensive than breath tests.

CONCLUSIONS

A peaking hydrogen breath test provides an alternative to scintigraphy for estimating intestinal transit after ileoanal pouch.

Clinical use of the self-expanding metallic stent in the management of colorectal cancer

PURPOSE

This report describes our experience with the use of self-expanding metallic stents (SEMS) in the management of obstructing colorectal cancer.

METHODS

A retrospective chart review of all patients undergoing placement of SEMS between May 1997 and January 2000 was performed.

RESULTS

Insertion of SEMS was attempted in 12 patients. Successful stent placement was achieved in 10 of the 12 patients. The locations of lesions were hepatic flexure (2), splenic flexure (1), left colon (1), sigmoid colon (4) and rectum (4). The intended uses of SEMS were for palliation in 3 patients and as a bridge to elective surgery in 9. In the latter group, SEMS placement allowed for preoperative bowel preparation in 4 patients and administration of neoadjuvant therapy prior to elective surgery in 2 patients. One patient died prior to definitive surgery. Stent placement was unsuccessful in 2 patients. Three SEMS-related complications occurred; 1 stent migrated and 1 stent obstructed secondary to tumor ingrowth. One patient died 13 days after stent placement and colonic decompression.

CONCLUSION

SEMS represent a useful tool in the management of obstructing colorectal neoplasms. As a bridge to surgery, SEMS provide time for a complete preoperative evaluation and a mechanical bowel preparation and may obviate the need for fecal diversion or on-table lavage. It may also allow for time to administer neoadjuvant therapy when indicated. As a palliative measure, SEMS can eliminate the need for an operation.

Familial adenomatous polyposis, hereditary nonpolyposis colon cancer, and familial risk: what are the implications for the surgeon?

Recent advances in the understanding of the molecular biology of colorectal cancer have resulted in many new implications for surgeons. To continue providing sound patient care, surgeons must familiarize themselves with associated issues that include genetic counseling and its role in patient and family management. Issues related to genetic counseling are reviewed in this article. Recommendations for surgical therapy and surveillance methods are summarized for each of the hereditary syndromes. Failure to use these patient management tools in an effective way may be a source of future litigation.

Safety and efficacy of dynamic graciloplasty for fecal incontinence: report of a prospective, multicenter trial. Dynamic Graciloplasty Therapy Study Group

PURPOSE

Dynamic graciloplasty has been used for intractable fecal incontinence, and good results have been reported. The aim of this study was to assess prospectively the safety and efficacy of dynamic graciloplasty for intractable fecal incontinence in a prospective, multicenter trial.

METHODS

A total of 123 adults were treated with dynamic graciloplasty at 20 institutions. Continence was assessed preoperatively and postoperatively by use of 14-day diaries.

RESULTS

There was one treatment-related death. One hundred eighty-nine adverse events occurred in 91 patients (74 percent). Forty-nine patients (40 percent) required one or more operations to treat complications. One hundred seventy (90 percent) events were resolved. Sixty-three percent of patients without pre-existing stomas recorded a 50 percent or greater decrease in incontinent events 12 months after dynamic graciloplasty, and an additional 11 percent experienced lesser degrees of improvement. Twenty-six percent were not improved, worsened, or exited. In patients with pre-existing stomas, 33 percent achieved successful outcomes at 12 months. This number increased to 60 percent at 18 months. Seventy-eight percent of patients had increased enema retention time, and mean anal canal pressures improved significantly at 12 months. Significant changes in quality of life were also observed.

CONCLUSIONS

Objective improvement can be demonstrated in the majority of patients with end-stage fecal incontinence treated with dynamic graciloplasty. Reduction in incontinence episodes can be correlated with improved quality of life. Adverse events are frequently encountered, but most resolve with treatment.

How I do it. Anal stenosis

BACKGROUND

Anal stenosis represents a technical challenge in terms of surgical management. It is a rare but serious complication of anorectal surgery, most commonly seen after surgical hemorrhoidectomy. However, stenosis can also occur in the absence of an anorectal surgical history.

DATA SOURCES

A review of the current surgical literature was performed. The etiology, classification, and diagnostic modalities for anal stenosis were reviewed. A detailed overview of surgical and nonsurgical therapeutic options was developed.

CONCLUSIONS

Anal stenosis may be anatomic (stricture) or functional (muscular). Anal stricture is most often a preventable complication. It is most commonly seen after overzealous surgical hemorrhoidectomy. A well-performed hemorrhoidectomy is the best way to avoid anal stricture. Symptomatic mild functional stenosis and stricture may be managed conservatively with diet, fiber supplements, and stool softeners. A program of gradual manual or mechanical dilatation may be required. Sphincterotomy and various techniques of anoplasty have been used successfully in the treatment of symptomatic moderate to severe functional anal stenosis and stricture, respectively.

Standards for anal sphincter replacement

PURPOSE

Anal sphincter replacement offers a new treatment option for patients with severe refractory fecal incontinence or for those who require abdominoperineal resection for localized malignancy. The purpose of this study was to review the current status of anal sphincter replacement, formulate a consensus statement regarding its current use, and outline suggestions for future development.

METHODS

Four areas of interests were selected: indications for sphincter replacement, continence scoring and quality of life, choice of therapy, and dissemination of new technology. A questionnaire regarding these issues was developed and circulated to working party members; its results served as the basis for this consensus document.

RESULTS

Both electrically stimulated skeletal muscle neosphincter and artificial anal sphincter are options for patients with end-stage fecal incontinence. Electrically stimulated skeletal muscle neosphincter is also appropriate for reconstruction after surgical excision of the anorectum in selected cases. Avoidance of complications requires strict attention to sterile technique, prophylactic antibiotics, and deep venous thrombus prophylaxis. A standardized scoring system is proposed that evaluates both continence and evacuation. Quality of life is a critical endpoint for assessing sphincter replacement, and use of The American Society of Colon and Rectal Surgeons incontinence-specific quality-of-life instrument is recommended. As the efficacy of sphincter replacement becomes proven, dissemination of the technique should occur in a controlled manner to ensure adequate surgeon training, minimization of complications, and optimization of results.

CONCLUSIONS

Sphincter replacement by electrically stimulated skeletal muscle neosphincter and artificial anal sphincter provide a continent option for patients with end-stage fecal incontinence and those requiring abdominoperineal resection. The guidelines offered in this document are intended to facilitate the controlled and safe development and acceptance of these new techniques.

Fecal Incontinence Quality of Life Scale: quality of life instrument for patients with fecal incontinence

PURPOSE

This goal of this research was to develop and evaluate the psychometrics of a health-related quality of life scale developed to address issues related specifically to fecal incontinence, the Fecal Incontinence Quality of Life Scale.

METHODS

The Fecal Incontinence Quality of Life Scale is composed of a total of 29 items; these items form four scales: Lifestyle (10 items), Coping/Behavior (9 items), Depression/Self-Perception (7 items), and Embarrassment (3 items).

RESULTS

Psychometric evaluation of these scales demonstrates that they are both reliable and valid. Each of the scales demonstrate stability over time (test/retest reliability) and have acceptable internal reliability (Cronbach alpha >0.70). Validity was assessed using discriminate and convergent techniques. Each of the four scales of the Fecal Incontinence Quality of Life Scale was capable of discriminating between patients with fecal incontinence and patients with other gastrointestinal problems. To evaluate convergent validity, the correlation of the scales in the Fecal Incontinence Quality of Life Scale with selected subscales in the SF-36 was analyzed. The scales in the Fecal Incontinence Quality of Life Scale demonstrated significant correlations with the subscales in the SF-36.

CONCLUSIONS

The psychometric evaluation of the Fecal Incontinence Quality of Life Scale showed that this fecal incontinence-specific quality of life measure produces both reliable and valid measurement.

Patient and surgeon ranking of the severity of symptoms associated with fecal incontinence: the fecal incontinence severity index

PURPOSE

The purpose of this research was to develop and evaluate a severity rating score for fecal incontinence, the Fecal Incontinence Severity Index.

METHODS

The Fecal Incontinence Severity Index is based on a type x frequency matrix. The matrix includes four types of leakage commonly found in the fecal incontinent population: gas, mucus, and liquid and solid stool and five frequencies: one to three times per month, once per week, twice per week, once per day, and twice per day. The Fecal Incontinence Severity Index was developed using both colon and rectal surgeons and patient input for the specification of the weighting scores.

RESULTS

Surgeons and patients had very similar weightings for each of the type x frequency combinations; significant differences occurred for only 3 of the 20 different weights. The Fecal Incontinence Severity Index score of a group of patients with fecal incontinence (N = 118) demonstrated significant correlations with three of the four scales found in a fecal incontinence quality-of-life scale.

CONCLUSIONS

Evaluation of the Fecal Incontinence Severity Index indicates that the index is a tool that can be used to assess severity of fecal incontinence. Overall, patient and surgeon ratings of severity are similar, with minor differences associated with the accidental loss of solid stool.

Influence of arginine dietary supplementation on healing colonic anastomosis in the rat

INTRODUCTION

This study sought to determine whether dietary arginine influences colonic anastomotic healing in the rat model.

METHODS

Three groups of 42 Sprague-Dawley rats were fed 0, 1, and 3 percent arginine diets for three preoperative and three postoperative days. Animals underwent transection of the transverse colon with hand-sewn anastomosis. Subgroups of 14 animals in each dietary group were killed on postoperative Days 6, 10, or 14, and bursting pressures, histologic inflammation, and collagen content were compared.

RESULTS

Mean anastomotic bursting pressures on postoperative Day 6 were lower for the 0 percent arginine group than the 1 and 3 percent arginine groups (mean +/- standard error of the mean = 134+/-6 mm Hg, 164+/-7 mm Hg, and 166+/-7 mm Hg, respectively; P<0.0005). On Days 10 and 14, no significant differences in bursting pressures were noted between arginine diets. Mean bursting pressures on postoperative Day 6 (155+/-4 mm Hg) were significantly lower than on Days 10 (204+/-5 mm Hg) and 14 (217+/-6 mm Hg; P<0.001) for all arginine diets. Microscopic evaluation of the anastomoses did not show significant differences in inflammation or collagen content between arginine diets. Collagen content in all dietary groups peaked at Day 10.

CONCLUSIONS

Perioperative arginine deficiency in the rat model is associated with impaired anastomotic healing during the first week, as reflected by lower bursting pressures. Arginine supplementation to 3 percent does not improve bursting pressures above those found in the usual 1 percent arginine diet at 6, 10, or 14 days. Bursting pressures plateau by Day 10 regardless of perioperative dietary arginine, whereas collagen content peaks at Day 10 after six-day perioperative arginine diet manipulation.

Colorectal cancer in hereditary breast cancer kindreds

PURPOSE

This study compared characteristics of colorectal cancer between families with dominant breast cancer inheritance and the general population. The cumulative incidence of colorectal cancer was also studied in genetically determined breast cancer syndrome subjects with BRCA1 and BRCA2 mutations and compared with the general population.

METHODS

Subjects included 42 patients with colorectal cancer from 32 clinically determined hereditary breast cancer kindreds based on the autosomal dominant inheritance of breast cancers and early age of onset. The general population colorectal cancer cohort was composed of 755 patients from a tumor registry. Lifetime risk of colorectal cancer was determined in 164 BRCA1 and 88 BRCA2 gene mutation carriers and compared with the general population. Mean age of colorectal cancer onset, anatomic site distribution, histologic stage at presentation, and five year stage-stratified survival rates were compared between clinically determined hereditary breast cancer family members and the general population.

RESULTS

The lifetime risk of colorectal cancer in male BRCA1 and BRCA2 mutation carriers was 5.6 percent, which was not different from 6 percent in males from the general population. Likewise, the lifetime colorectal cancer risk in female BRCA1 and BRCA2 mutation carriers was 3.2 percent, which was not different from 5.9 percent in females from the general population. Mean age of onset +/- standard error for patients with colorectal cancer was 60 +/- 2 years for hereditary breast cancer kindreds compared with 67 +/- 0.4 years for the general population (P = 0.0004). Colorectal cancer site distribution did not vary between hereditary breast cancer and the general population. Overall colorectal cancer stage distribution was significantly different, with more Stage I and fewer Stage IV cancers in subjects with hereditary breast cancer compared with the general population (P = 0.01). Overall five year stage-stratified colorectal cancer survival rate +/- standard error was 66 +/- 8 percent for hereditary breast cancer kindreds and 46 +/- 2 percent for the general population (P = 0.023).

CONCLUSION

Lifetime cumulative colorectal cancer incidence in subjects with BRCA1 and BRCA2 gene mutations was not different from the general population. However, significant differences in colorectal cancer were noted between hereditary breast cancer family members and the general population. Hereditary breast cancer-associated colorectal cancer had an earlier age of onset, lower tumor stage, and better survival rate than the general population. Except for age of onset, colorectal cancer in hereditary breast cancer kindreds exhibited more favorable characteristics than colorectal cancer in the general population.

Histologic comparison of hereditary nonpolyposis colorectal cancer associated with MSH2 and MLH1 and colorectal cancer from the general population

PURPOSE

Hereditary nonpolyposis colorectal cancer is reported to have special histologic features. This study compares the histologic features of hereditary nonpolyposis colorectal cancer to colorectal cancers from the general population when hereditary nonpolyposis colorectal cancer cases are restricted to families with known MSH2 and MLH1 mutations.

METHODS

Thirty-seven cancers from kindreds carrying MSH2 mutations, 27 cancers from kindreds carrying MLH1 mutations, and 37 colorectal cancers from the general population were reviewed by a pathologist blinded to hereditary nonpolyposis colorectal cancer gene status. Tumor grade, growth pattern, Crohn's-like lymphoid reaction, mucin production, extent of disease in the bowel wall, and lymph node status were evaluated.

RESULTS

Poor differentiation and Crohn's-like reaction were a feature of 44 and 49 percent of hereditary nonpolyposis colorectal cancer compared with 14 percent (P = 0.002) and 27 percent (P = 0.049) of colorectal cancers from the general population, respectively. There was no difference in growth pattern, mucin production, lymph node involvement, or local extent of disease between hereditary nonpolyposis colorectal cancer and colorectal cancers from the general population. Poor differentiation and lymph node metastases were found in 57 and 49 percent of MSH2 compared with 26 percent (P = 0.002) and 10 percent (P = 0.03) of MLH1-associated cancers, respectively. There was no difference in growth pattern, mucin production, Crohn's-like lymphoid reaction, or local extent of disease between subgroups of hereditary nonpolyposis colorectal cancer.

CONCLUSIONS

Poor differentiation and Crohn's-like reaction are more common in hereditary nonpolyposis colorectal cancer than colorectal cancers from general population. Poor differentiation and lymph node metastases are more commonly seen in MSH2-associated cancers than MLH1. Evaluation of the natural history, pathogenesis, and prognosis of colorectal cancer in hereditary nonpolyposis colorectal cancer should include consideration of which mismatch repair genes are mutated and what the specific mutations are.

Use of preoperative ultrasound staging for treatment of rectal cancer

INTRODUCTION

Transrectal ultrasound is the standard method for preoperative staging of rectal cancer. This study reviews the accuracy of transrectal ultrasound staging for T3 disease and its use in the selection of patients for neoadjuvant chemoradiation.

METHODS

One hundred seventeen patients underwent preoperative transrectal ultrasound evaluation for rectal cancer. Accuracy of transrectal ultrasound was evaluated among 70 patients not receiving preoperative chemoradiation. Forty-seven patients received neoadjuvant chemoradiation based on transrectal ultrasound results. Tumor downstaging and early recurrence were evaluated among 45 of 47 patients receiving neoadjuvant chemoradiation.

RESULTS

Among 70 nonirradiated patients, 19 were pathologic Stage pT3. Transrectal ultrasound correctly identified 18 of 19 patients with Stage pT3 (sensitivity, 94.7 percent). Transrectal ultrasound correctly identified 44 of 51 patients with less than pT3 disease (specificity, 86.3 percent). After preoperative chemoradiation in 45 patients with ultrasound Stage uT3 or uT4 tumors, 56 percent of them experienced a reduction in T stage. Residual nodal disease was found in 31 percent of patients. A complete pathologic response with no residual disease at operation was observed in 22 percent of patients. During a median follow-up period of 21 months after diagnosis, seven patients experienced a recurrence of their disease at a median of 12 months after diagnosis. Five of seven patients with recurrence were among a subgroup of ten patients who both failed to downstage T and had residual nodal disease at operation.

CONCLUSION

Transrectal ultrasound is an accurate modality for selecting patients for neoadjuvant treatment. Preoperative chemoradiation produced downstaging in 56 percent of patients. Factors related to early recurrence included residual nodal disease and failure to downstage T after neoadjuvant chemoradiation.

A century of progress in hereditary nonpolyposis colorectal cancer (Lynch syndrome)

One of the earliest references to heredity in colorectal cancer dates to Aldred Warthin's now-famous recollection of his seamstress' distress regarding "cancer excess" in her family history. Her prediction of an early demise secondary to cancer of the female organs, colon, or stomach proved true. The slow, arduous investigation that ensued followed a tortuous route of nearly eight decades before the implications of such family histories were widely acknowledged through the designation of hereditary nonpolyposis colorectal cancer or Lynch Syndrome Variants I and II. The story of hereditary nonpolyposis colorectal cancer is one of chance meetings, the selfless sharing of information, perseverance in the face of adversity, meticulous scientific documentation, and ultimate vindication by a scientific process that yielded molecular genetic evidence through the identification of the culprit mutations (hMSH2, hMLH1, hPMS2, and hMSH6). Our purpose is to provide a brief outline of the course charted by the study of the genetics of hereditary nonpolyposis colorectal cancer. This should be of particular interest to the readers of this Journal as we celebrate 100 years of dedication to the diagnosis and treatment of diseases of the colon, rectum, and anus through the efforts of The American Society of Colon and Rectal Surgeons.

Ileoanal pouch function and release of peptide YY

PURPOSE

This study evaluates peptide tyrosine-tyrosine (PYY), intestinal transit, fecal retention time, and anal sphincter manometry in colectomized patients with ileal pouch-anal anastomosis.

METHODS

Plasma and pouch PYY, mouth-to-pouch transit time, fecal retention time, and anal canal pressures were studied in 27 patients with ileoanal pouches a mean of 50 (range, 3-84) months after loop ileostomy closure.

RESULTS

Basal and peak postprandial plasma PYY were significantly reduced in patients with pouches compared with controls (P < 0.0001). Pouch PYY was decreased compared with control ileal PYY (P = 0.0003). No significant correlation was noted between intestinal transit and total integrated PYY response in patients with pouches (r=0.36; P=0.06). Fecal retention time was related to postprandial total integrated response of plasma PYY (r=0.43; P=0.02), mouth-to-pouch transit (r=0.87; P < 0.0001), and resting (r=0.44; P=0.02) and squeeze (r=0.62; P=0.0006) anal sphincter pressures.

CONCLUSIONS

Colectomized ileoanal patients with pouches showed decreased plasma and pouch PYY compared with controls. Intestinal transit was not significantly related to PYY release. However, prolonged pouch fecal retention was associated with greater PYY release, mouth-to-pouch transit, and anal sphincter pressures.

Colorectal and extracolonic cancer variations in MLH1/MSH2 hereditary nonpolyposis colorectal cancer kindreds and the general population

PURPOSE

This clinical case review aimed to identify phenotypic variations in colorectal and extracolonic cancer expression between hereditary nonpolyposis colorectal cancer (HNPCC) families with MLH1 and MSH2 germline mutations and the general population.

METHODS

Colorectal cancer onset and site distribution were compared among 67 members of MLH1 kindreds, 45 members of MSH2 kindreds, and 1,189 patients from the general population. Synchronous and metachronous cancer rates, tumor stage, extracolonic cancer incidence, and survival were also compared.

RESULTS

Mean ages of colorectal cancer onset were 44, 46, and 69 years for MLH1, MSH2, and the general population, respectively (P < 0.001). More proximal and fewer distal colon cancers were noted in HNPCC than the general population (P < 0.001, P = 0.04). Site distribution showed disparity of rectal cancers (8 percent MLH1 vs. 28 percent MSH2; P = 0.01) based on genotypes. Overall, synchronous colorectal cancer rates were 7.4, 6.7, and 2.4 percent for MLH1, MSH2, and the general population, respectively (P = 0.016). Annual metachronous colorectal cancer rates were 2.1, 1.7, and 0.33 percent for MLH1, MSH2, and the general population, respectively (P = 0.041). Colorectal cancer stage presentation was lower in HNPCC than the general population (P = 0.0028). Extracolonic cancers were noted in 33 percent of MSH2 patients, compared with 12 percent of MLH1 patients and 7.3 percent of the general population with colorectal cancers (P < 0.001). Combined MLH1 and MSH2 ten-year survival was 68.7 percent compared with 47.8 percent for the general population (P = 0.009 stage stratified, hazard ratio 0.57).

CONCLUSION

The presence of rectal cancer should not preclude the diagnosis of HNPCC, because the incidence of rectal cancer in MSH2 was comparable with that in the general population. Phenotypic variations, including the preponderance of extracolonic cancers in MSH2 patients, did not result in survival differences between genotypic subgroups. These phenotypic features of HNPCC genotypes may have clinical significance in the design of specific screening, surveillance, and follow-up for affected individuals.

Cumulative incidence of colorectal and extracolonic cancers in MLH1 and MSH2 mutation carriers of hereditary nonpolyposis colorectal cancer

The extracolonic tumor spectrum of hereditary nonpolyposis colorectal cancer (HNPCC) includes cancer of the endometrium, ovaries, stomach, biliary tract, and urinary tract. This study was designed to determine the penetrance of colorectal and extracolonic tumors in HNPCC mutation carriers. Forty-nine patients (22 females and 27 males) were identified with an MSH2 germline mutation, and 56 patients (28 females and 28 males) were identified with an MLH1 I mutation. Cumulative incidence by age 60 (lifetime risk) and mean age of cancer diagnosis were compared. The lifetime risk of extracolonic cancers in MSH2 and MLH1 carriers was 48% and 11%, respectively (P = 0.016). Extracolonic cancer risk in MSH2 females and males was 69% and 34%, respectively (P = 0.042). Mean age of extracolonic cancer diagnosis was significantly older for MSH2 males than females (55.4 vs. 39.0, P = 0.013). No difference was observed in colorectal cancer risk between MLH1 and MSH2 carriers (84% vs. 71%). Colorectal cancer risk was 96% in MSH2 males compared to 39% in MSH2 females (P = 0.034). No differences in colorectal and extracolonic cancer risks between MLH1 females and males were identified. The risk of extracolonic cancer by age 60 was greater in MSH2 mutation carriers than in MLH1 carriers. Gender differences in colorectal and extracolonic cancer risk were observed for MSH2 carriers only. These phenotypic features of HNPCC genotypes may have clinical significance in the design of genotype-specific screening, surveillance, and follow-up for affected individuals.

Pudendal nerve function in normal and encopretic children

BACKGROUND

Abnormal pudendal nerve function contributes to fecal retention and incontinence in adults. To determine the role of pudendal neuropathy in childhood, we prospectively evaluated pudendal nerve function in normal and encopretic children.

METHODS

We studied pudendal nerve terminal motor latency in 23 encopretic children and in an equal number of similarly aged, normal children. Anal manometry and electromyography were also obtained in all children.

RESULTS

Pudendal nerve latency in the encopretic children equaled 1.58 +/- 0.33 msec, which was the same as that in control children. Of the 75 pudendal nerves tested, latency was prolonged in only one encopretic child. In contrast, anal electromyography demonstrated nonrelaxation of the external anal sphincter in 75% of the encopretic children but in only 13% of the normal children (p < 0.001). Anorectal manometry demonstrated, on average, lower and sphincter pressures at rest and with squeezing in the encopretic children (p < 0.01), but only 17% had sphincter pressures more than two standard deviations below normal.

CONCLUSIONS

Other than poor relaxation response of the external anal sphincter during evacuation, these data reveal a paucity of functionally important abnormalities in encopretic children. In particular, we find no evidence that abnormal pudendal nerve function is important in the etiology or pathogenesis of encopresis in children.

Diagnosing anal sphincter injury with transanal ultrasound and manometry

PURPOSE

This study was undertaken to evaluate how well anorectal manometry and transanal ultrasonography diagnose anal sphincter injury.

METHODS

Anorectal manometry and transanal ultrasonography were performed in 20 asymptomatic nulliparous women and 20 asymptomatic parous women, and the results were compared with those obtained in 31 incontinent women who subsequently underwent sphincteroplasty and, thus, had operatively verified anal sphincter injury. By using computerized manometry analysis, mean maximum resting and squeeze pressures, sphincter length, and vector symmetry were determined in all women. All transanal ultrasounds were interpreted blinded as to the patient's history, physical examination, and manometry results.

RESULTS

Manometric resting and squeeze pressures were significantly higher in the asymptomatic nulliparous women than in the asymptomatic parous women, and both groups had significantly higher pressures than the incontinent women (P < 0.001). Anal sphincter length and vector symmetry index were significantly decreased in incontinent women compared with asymptomatic women (P < 0.01). Decreased resting and squeeze pressures suggestive of possible sphincter injury were found in 90 percent of incontinent women with known anal sphincter injury. Decreased anal sphincter length and vector symmetry were found in only 42 percent of women with known anal sphincter injury. Transanal ultrasound was able to identify 100 percent of the known sphincter injuries but also falsely diagnosed injury in 10 percent of the asymptomatic nulliparous women with intact anal sphincters. False identification of sphincter injury increased when transanal ultrasound scanning was performed proximal to the distal 1.5 cm of the anal canal.

CONCLUSION

Although nonspecific, decreased resting and squeeze pressures were found in 90 percent of patients with anal sphincter injury. Decreased anal sphincter length or vector symmetry index were present in only 42 percent of patients with known sphincter injury. When limited to the distal 1.5 cm of the anal canal, transanal ultrasound identified all known sphincter injuries but falsely identified injury in 10 percent of women with intact anal sphincters. Transanal ultrasound in combination with decreased anal pressures correctly identified all intact sphincters and 90 percent of known anal sphincter injuries.

Transanal ultrasound and anorectal physiology findings affecting continence after sphincteroplasty

PURPOSE

This study was undertaken to evaluate endosonographic and physiologic determinants of fecal continence after sphincteroplasty.

METHODS

Sixteen female patients with severe fecal incontinence were treated with overlapping sphincteroplasty. Mean postoperative follow-up was 12 (range, 3-48) months. All patients underwent preoperative and postoperative transanal endosonography and anal manometry. Bilateral pudendal nerve terminal motor latency determinations were performed in each patient. A physiologic continence score was used to assess stool control.

RESULTS

Postoperatively, continence was worse, unchanged, and improved in one, five, and ten patients, respectively. An inverse correlation was noted between endosonographic sphincter discontinuity postoperatively, in degrees, and the change in fecal continence after overlapping sphincteroplasty (r = -0.51; P = 0.04). Postoperative increases in sphincter resting (r = 0.6; P = 0.02) and squeeze (r = 0.54; P = 0.03) pressures correlated with improved fecal continence. Mean pudendal nerve terminal motor latency (r = -0.34; P = 0.20) and changes in anal sphincter length at rest (r = 0.41; P = 0.11) and squeeze (r = 0.33; P = 0.20) after sphincteroplasty did not significantly correlate with the change in continence. Patients with intact endosonographic anatomy postoperatively and bilateral, unilateral, or no evidence of pudendal neuropathy had a mean change in continence score of 0.5, 1.8, and 2.2, respectively (P = 0.48).

CONCLUSIONS

Endosonography after sphincteroplasty can identify residual sphincter defects that are significant in terms of fecal continence. Restoration of anal canal resting and squeeze pressures was related to improved fecal control after overlapping sphincteroplasty. Mean pudendal nerve terminal motor latency was not significantly related to poor postoperative continence. A trend toward less improvement in fecal continence was noted with bilateral pudendal neuropathy.

Operative results of House advancement anoplasty

A retrospective review of 29 patients who had an anoplasty using the sliding House advancement flap was carried out to evaluate the efficacy and safety of this new technique. Long-term symptom relief and late complications were determined by telephone interview. Indications for anoplasty were: stenosis (21 cases), ectropion (four), Bowen's disease (two), keyhole deformity (two) and perineal fistula (one). A single House flap was performed in most patients, but eight required multiple flaps. Lateral internal sphincterotomy was performed concomitantly in 16 of 21 patients with anal stenosis. Postoperative complications included donor-site separation (14), urinary retention (eight) and sepsis (four). At a median follow-up of 28 months, 26 of 29 patients had improved and 24 were completely satisfied. House flap anoplasty can be used to correct many anoderm deficiencies with a high rate of success and patient satisfaction.

Preoperative chemoradiation downstages locally advanced ultrasound-staged rectal cancer

BACKGROUND

This prospective study assessed the effect of preoperative radiation and chemotherapy on the pathologic staging of advanced rectal cancer.

METHODS

Twenty patients with rectal cancer were treated with combined chemoradiation prior to operation, after pretreatment staging of all lesions with transrectal ultrasound (TRUS). Perirectal fat invasion served as minimal criteria for preoperative neoadjuvant therapy. The pretreatment stage of these rectal lesions as defined by TRUS was then compared with the pathological stage of the surgical specimen following resection. Cancers were treated with high-dose radiation (45 to 54 Gy) in 19 of 20 patients. One patient received in excess of 60 Gy because of tumor characteristics. Chemotherapy consisted of 5-fluorouracil delivered as a continuous infusion or bolus therapy. Four to 8 weeks after neoadjuvant therapy, 13 abdominal perineal resections, 5 low anterior resections, and 2 completion proctectomies were performed.

RESULTS

Following resection, rectal cancer was downstaged in 14 of 20 patients. No tumor was present in the rectal wall in 8 of 20 patients. Complete pathological response was present in 7 of 20 patients. Local recurrence occurred in 2 of 20 patients. Disease-free survival in the remaining 17 of 20 patients ranges from 9 to 51 months (average 26).

CONCLUSIONS

Preoperative chemoradiation in the surgical management of advanced rectal cancer results in demonstrable tumor downstaging.

Simultaneous dynamic proctography and peritoneography for pelvic floor disorders

PURPOSE

We sought to evaluate a new diagnostic technique for the identification of rectal and pelvic floor pathology in patients with obstructed defecation, pelvic fullness/prolapse, and/or chronic intermittent pelvic floor pain.

METHODS

Thirteen symptomatic women with either a nondiagnostic physical examination or nondiagnostic dynamic proctography (DPG) were studied. After placement of intraperitoneal and intrarectal contrast material, resting and straining pelvic x-rays were obtained in all patients, and defecation was videotaped using fluoroscopy.

RESULTS

Simultaneous DPG and peritoneography identified clinically suspected and unsuspected enteroceles in 10 of the 13 patients studied. An enterocele or other pelvic floor hernia was ruled out by the technique in three of the women studied. Rectoceles and rectal prolapse that were identified during physical examination were confirmed by DPG with peritoneography. Simultaneous DPG and peritoneography also gave a qualitative assessment of the severity and clinical significance of the identified pelvic floor disorders. Results of simultaneous DPG and peritoneography affected operative treatment planning in 85 percent of patients studied.

CONCLUSION

Simultaneous DPG and peritoneography identifies both rectal and pelvic floor pathology and provides a qualitative assessment of pelvic floor pathology severity, which allows for better treatment planning in selected patients with obstructed defecation and pelvic prolapse.

Rectal cancer after prolonged sulindac chemoprevention. A case report

BACKGROUND

Sulindac is reported to induce regression of colonic adenomas. However, its role as a chemoprophylactic agent for people with familial adenomatous polyposis (FAP) is under consideration.

METHODS

This case report describes a patient with FAP in whom rectal adenocarcinoma developed 37 years after prophylactic colectomy and 15 months after beginning a course of sulindac. She received endoscopic follow-ups every 3 months during 15 months of 150-mg twice-daily sulindac administration. At 12 months, an endoscopic examination was unremarkable; at 15 months, endoscopic examination revealed several polyps and a flat ulcerated lesion.

RESULTS

Rectal carcinoma developed in a patient 15 months after beginning chemoprophylaxis: there was metastatic adenocarcinoma in 6 of 20 perirectal lymph nodes. In addition to the carcinoma, rectal mucosa contained two adenomas and multiple foci of adenomatous changes in flat mucosa.

CONCLUSION

Sulindac may not alter the pathogenesis of FAP. Patients undergoing sulindac chemoprevention must be monitored closely, including endoscopic examination. Endoscopic surveillance should include an aggressive biopsy approach because the absence of polyps does not prove the absence of neoplastic change.

Patterns of male fecal incontinence

PURPOSE

This study sought to identify clinical and manometric characteristics of male fecal incontinence.

METHOD

Clinical charts of 25 men with a chief complaint of fecal incontinence were retrospectively reviewed. Their anorectal physiology test results were compared with those from a group of 20 healthy men.

RESULTS

Fourteen men (56 percent) were "leakers," who complained of loss of liquid or solid stool smears that stained their underclothes. Eleven men (44 percent) had true incontinence, with loss of control over gas, liquid, and/or solid stool. Leakers had lower anal sphincter pressures than normal men (P < 0.05) but higher pressures than incontinent men (P < 0.05). In leakers the anal sphincter length at rest was longer than in incontinent (P < 0.01) and normal men (P < 0.05). All incontinent men had decreased manometric pressures, abnormal anorectal sensation or prolonged pudendal nerve terminal motor latencies, whereas only one-half of the leakers had physiologic abnormalities. Treatment using dietary manipulation, constipating agents or cleansing enemas was successful in nearly 90 percent of incontinent men but only 55 percent of the leakers.

CONCLUSIONS

Whereas true incontinence in men is caused by a short, low pressure sphincter with altered sensation or innervation, leakage is associated with a long, intermediate pressure sphincter that frequently has normal sensation and innervation. This long, intermediate pressure sphincter may predispose these men to leakage. Treatment of leakers is less successful than treatment of incontinent men. Leakers and incontinent men have unique clinical and physiologic profiles that should be identified to help guide treatment and determine prognosis.

Rectal cancer after prolonged sulindac chemoprevention. A case report

BACKGROUND

Sulindac is reported to induce regression of colonic adenomas. However, its role as a chemoprophylactic agent for people with familial adenomatous polyposis (FAP) is under consideration.

METHODS

This case report describes a patient with FAP in whom rectal adenocarcinoma developed 37 years after prophylactic colectomy and 15 months after beginning a course of sulindac. She received endoscopic follow-ups every 3 months during 15 months of 150-mg twice-daily sulindac administration. At 12 months, an endoscopic examination was unremarkable; at 15 months, endoscopic examination revealed several polyps and a flat ulcerated lesion.

RESULTS

Rectal carcinoma developed in a patient 15 months after beginning chemoprophylaxis: there was metastatic adenocarcinoma in 6 of 20 perirectal lymph nodes. In addition to the carcinoma, rectal mucosa contained two adenomas and multiple foci of adenomatous changes in flat mucosa.

CONCLUSION

Sulindac may not alter the pathogenesis of FAP. Patients undergoing sulindac chemoprevention must be monitored closely, including endoscopic examination. Endoscopic surveillance should include an aggressive biopsy approach because the absence of polyps does not prove the absence of neoplastic change.

Transanal ultrasound and manometry in the evaluation of fecal incontinence

PURPOSE

This preliminary study was undertaken to clarify the role of ultrasonography of anal sphincters in the colorectal laboratory.

METHODS

Twenty-eight parous female patients with fecal incontinence were evaluated with transanal ultrasonography (TAUS), anal manometry, and pudendal nerve terminal motor latency (PNTML). Ultrasound images were recorded and labeled in centimeters from the anal verge. The continuity of the internal anal sphincter (IAS) was identified as either intact or disrupted. The separation of the external anal sphincter (EAS) was measured at the 1.5-cm level and below. TAUS findings were then compared with anal manometric pressures. Clinical data were obtained by patient interview and examination during TAUS.

RESULTS

Evidence of IAS disruption was associated with significantly decreased mean maximum resting pressures (P = 0.023). EAS separation was inversely proportional to mean maximum squeezing pressures (r = -0.61). In the group of patients offered sphincteroplasty, the IAS was disrupted more often (P = 0.016), mean maximum resting pressures were significantly lower (P = 0.023), mean EAS separation was significantly greater (P = 0.022), and mean PNTML was significantly faster (P = 0.004). Twenty-five percent of patients with normal clinical examinations had significant muscular injury by TAUS requiring sphincteroplasty.

CONCLUSIONS

Manometric findings correlate significantly with anal sphincter defects visualized by TAUS. TAUS is useful in the evaluation and management of patients with fecal incontinence.

Positron emission tomography for preoperative staging of colorectal carcinoma

PURPOSE

Positron emission tomography (PET) is an imaging technique based on in vivo cellular metabolism. Increased glucose metabolism in neoplastic cells is detected by using fluorine-18 deoxyglucose. In an ongoing pilot study to determine the usefulness of this technique, PET is compared with computerized tomography (CT) for the preoperative staging of colorectal carcinoma.

METHODS

Sixteen patients were evaluated with both PET and CT of the abdomen and pelvis. Results were compared with operative and histopathologic findings. Fifteen malignant lesions were found in 16 patients by histology. PET had a positive predictive value of 93 percent and a negative predictive value of 50 percent. By comparison CT had a positive predictive value of 100 percent and a negative predictive value of 27 percent.

CONCLUSIONS

These preliminary results indicate that PET has increased sensitivity for staging colorectal carcinoma, whereas CT has higher specificity. The predictive value of a positive PET compares favorably with CT. Furthermore, the predictive accuracy for detection of colorectal carcinoma is 83 percent for PET and 56 percent for CT.

Colonic anastomoses: bursting strength after corticosteroid treatment

PURPOSE

This study was designed to determine the effect of corticosteroids on healing colonic anastomoses.

METHODS

Bursting pressure measurements were performed on 108 male albino rats receiving corticosteroid treatment. Twelve animals were sacrificed at time zero to determine the bursting pressure of nonoperated, nonsteroid-treated colon. The remaining 96 animals underwent division and reanastomosis of their midtransverse colon. They were then separated into four groups of 24 each. Twelve animals in each group received steroid treatment while the remaining 12 acted as controls. The groups were sacrificed at 4, 6, 8, and 20 days. The bursting pressures of the anastomoses were then noted.

RESULTS

There was no significant difference in bursting strength between treated animals and controls at four days (P = 0.27). A significant difference occurred at 6, 8, and 20 days (P = 0.01, 0.003, 0.009, respectively). The colonic bursting pressure of operated controls returned to that of a normal, nonoperated colon by 20 days.

CONCLUSION

This study demonstrates that steroids do have an adverse effect on colonic anastomotic healing.

Effect of prostaglandin E1 and steroid on healing colonic anastomoses

PURPOSE

The effect of prostaglandin E1 (PGE1) and corticosteroids alone and in combination were studied in the healing rat colon to determine whether PGE1 could not only improve healing but reverse the negative effect of steroids on colonic wound healing.

METHODS

Colonic anastomoses were performed in 144 male Sprague-Dawley rats divided into four groups. The control group (I) received no further treatment. The steroid group (II) received cortisone acetate (5 mg/kg/day) beginning six days preoperatively and continuing until sacrifice. The PGE1 group (III) received 2 micrograms of PGE1 intra-aortically at surgery and for three days postoperatively. The combination PGE1/steroid group (IV) received both drugs in the same doses as those in Groups II and III. Animals were sacrificed on postoperative days 6, 10, and 14. Wound healing was evaluated by hydroxyproline content, bursting pressures, and histology.

RESULTS

The hydroxyproline assay at day 10 revealed that steroid-treated rats have significantly lower levels than any other group. The PGE1 group (III) had the highest level of significance in comparison to the steroid group (II) (P = 0.001). The addition of PGE1 to steroid (Group IV) appeared to abolish the negative effect of the steroid as measured by hydroxyproline content on day 10 (P = 0.038). When measuring bursting pressures, the PGE1 group (III) had significantly higher pressures than any other group at day 10. However, no amelioration of the steroid effect on bursting pressures was seen. Histologic evaluation of the anastomosis did not reveal any significant differences among the four groups.

CONCLUSIONS

PGE1 reverses the negative effect of the steroid on hydroxyproline levels at day 10. Furthermore, using bursting pressure as a parameter of wound healing, administration of PGE1 results in significantly improved anastomotic healing at day 10.

Transrectal ultrasound of rectal tumors

Since preoperative staging of rectal tumors is important in planning treatment, we evaluated transrectal ultrasound (TRUS) staging of rectal neoplasms. In 35 consecutive rectal tumors, we compared TRUS staging results with final pathologic staging. TRUS predicted the degree of tumor invasion in 19 of 24 patients (79%) and the presence or absence of lymph node metastasis in 11 of 15 patients (73%). TRUS overestimated the degree of tumor invasion in four patients (17%) and underestimated invasion in one patient (4%). The depth of tumor invasion was correctly predicted in all 14 tumors located within 6 cm from the anal verge, but, beyond 6 cm, only 5 of 10 tumors (50%) were staged correctly (p = 0.005). In the group of 11 patients who underwent preoperative radiotherapy, pretreatment TRUS predicted the depth of tumor invasion in only six patients (55%) and overestimated tumor invasion in five patients (45%), suggesting that nearly half of these tumors were downstaged by radiotherapy. TRUS accurately predicts the degree of tumor invasion, especially in tumors closer to the anal verge, allowing for better treatment planning in patients with low to middle rectal neoplasms.

Cumulative incidence of metachronous colorectal cancer

The incidence of metachronous colorectal cancer has most often been reported as a crude rate: second cancers/index cancers. The reported incidence varies between 0.5 percent and 3.6 percent. However, these calculations do not take into account factors such as length of survival and length of follow-up. The cumulative incidence more accurately reflects the risk for developing a metachronous cancer and was determined in a retrospective analysis of 5,476 patients who were diagnosed with colon or rectal cancer between 1965 and 1985. The cumulative probability was calculated by determining the number of patients developing a metachronous colon cancer vs. the number remaining at risk at that point in time. The calculated annual incidence for metachronous tumors was 0.35 percent per year. The cumulative incidence at 18 years was 6.3 percent. Analysis also demonstrated that metachronous cancers were diagnosed at earlier stages than were index cancers (P = 0.03). Subgroup analysis was performed on patients diagnosed with metachronous cancer before and after 1980. There was a difference in the incidence of metachronous cancers between these two groups (P = 0.04).

Laparoscopic colectomy: a critical appraisal

A multicenter retrospective study was undertaken to assess the efficacy and safety of laparoscopy in colon and rectal surgery. To minimize potential bias in interpretation of the results, all data were registered with an independent observer, who did not participate in any of the surgical procedures. Sixty-six patients underwent a laparoscopic procedure. Operations performed included sigmoid colectomy (19), right hemicolectomy (15), low anterior resection (6), colectomy with ileal pouch-anal anastomosis (IPAA) (5), and abdominoperineal resection (APR) (3). The conversion rate from laparoscopic colectomy to celiotomy was 41 percent. Major morbidity and mortality were 24 percent and 0 percent, respectively. Length of stay, hospital costs, and lymph node harvest were compared between the sigmoid resection and right hemicolectomy subgroups. Data from traditional sigmoid colectomies and right hemicolectomies were obtained from the same institutions for comparison. Mean postoperative stay for laparoscopically completed sigmoid and right colectomies was significantly less than that for either the converted or the traditional groups (P < 0.02). Total hospital cost for traditional right hemicolectomy was significantly less than that for the converted group (P < 0.05) but not the laparoscopic group. Laparoscopic sigmoid resection showed no significant total hospital cost difference among traditional, converted, and laparoscopic groups. Lymph node harvest in resections for carcinoma was comparable in all groups. These preliminary data suggest that laparoscopic colon and rectal surgery can be accomplished with acceptable morbidity and mortality when performed by trained surgeons. Length of stay is shorter, but there is no proven total hospital cost benefit. Appropriate registries will be necessary to adequately assess long-term outcome.

Normal variation in anorectal manometry

A study was performed to define the normal range of values for anorectal manometry. Normal volunteers were divided according to gender and parity. There were 20 males, 21 nulliparous females, and 18 multiparous females among the 59 subjects. Anorectal manometry using a radial eight-port catheter was performed during resting and squeezing maneuvers of the anal sphincter. Computerized data analysis and three-dimensional imaging were used to calculate sphincter length at rest and squeeze, mean maximum resting and squeeze pressures, and vector symmetry index. The sphincter length at rest and with squeezing in males was significantly greater compared with the two female groups (P < 0.007). Mean maximum squeeze pressures were also significantly elevated in the male group compared with the female groups (P = 0). Mean maximum resting pressures were significantly higher in nulliparous women than in multiparous women (P = 0.04). However, no difference in resting pressures was found between males and nulliparous females. A comparison of the symmetry of the anal canal revealed no differences among the three groups. Ranges for normal anorectal manometry are definable. Normal ranges are distinct for subgroups of patients, particularly with regard to gender and parity. Patients must be compared with their normal subgroups to correctly identify manometric abnormalities.

"House" advancement pedicle flap for anal stenosis

Long strictures of the anal canal, extending from the dentate line to the perianal skin, have challenged surgeons for many years. Numerous techniques have been devised to treat anal strictures. A technique to relieve an anal stenosis that involves the entire circumference and the length of the anal canal from the dentate line onto the perianal skin is described. It has two principal advantages: 1) it provides a broad skin flap for the entire length of the involved anal canal; and 2) it provides primary closure of the donor site. In addition, it avoids extensive mobilization of tissue, the flap maintains good blood supply with minimal tension, and there is no small tip prone to necrosis.

Manometric diagnosis of anal sphincter injuries

A manometric technique of anal pressure vectography has been developed for the detection of anal sphincter injuries. Manometric symmetry of the anal sphincter can be visualized on the pressure vectorgram and quantified as a vector symmetry index. The mean vector symmetry index in asymptomatic women was 0.76, compared with 0.33 in incontinent women with a known sphincter injury (p = 0.0001). Among women who were incontinent without having a recognized sphincter injury, nearly half of those who had a previous episiotomy had subnormal (less than 0.60) vector symmetry indices (p = 0.0003). The values were in the same range as those from known injuries, suggesting the presence of an occult sphincter injury. In contrast, normal symmetry indices were found in all those who had never had an episiotomy or who presented with outlet constipation. We conclude that the vector symmetry index can expose occult anal sphincter injuries and may have a role in the selection of patients for sphincter repair.

Office colonoscopy--a safe procedure in selected patients

Colonoscopy is a common procedure, usually performed in a hospital setting. Hospital backup is desirable for high-risk patients, but the cost to benefit ratio may be unnecessarily high for low-risk patients. The demand for colonoscopic examinations is escalating, and cost containment has become an important issue. One way to reduce the cost is to eliminate the hospital component by performing the examination in the office. Over the past two and a half years, colonoscopy was performed on selected patients in the authors' office. Five hundred fifty-four office colonoscopies were performed to date, including biopsy or polypectomy in 348. Basic principles of safe intravenous sedation and colonoscopy were followed strictly. The cecum was reached in 92 percent of cases, and no significant complications were encountered. Office colonoscopy is a safe alternative to hospital colonoscopy. It confers significant cost savings to the patient and allows more efficient use of the physician's time.

Rectopexy without resection for rectal prolapse

Forty-three patients underwent simple posterior suture rectopexy for repair of rectal prolapse. Follow-up was obtained in 42 patients (mean 28 months). The recurrence rate was 2 percent (one patient). Postoperative morbidity and mortality were 20 percent and 0, respectively. The proportion of continent patients increased from 36 percent preoperatively to 74 percent postoperatively. Constipation increased after suture rectopexy but was managed conservatively. We believe that simple suture rectopexy offers a safe and effective alternative to other, more complex procedures for the treatment of rectal prolapse.

Rectal prolapse: rational therapy without foreign material

A number of operations are available for the correction of rectal prolapse. Rational judgement is required for the selection of the most appropriate procedure for each patient. Perineal rectosigmoidectomy offers a reasonable alternative to an abdominal procedure in patients who are elderly and debilitated. Simple suture rectopexy is our procedure of choice for an abdominal prolapse repair. We believe that simple rectopexy offers comparable results with less risk than procedures utilizing resection or foreign material. Colon resection should be reserved for those patients who require surveillance for colon polyps or have a history of diverticulitis.

Repair of simple rectovaginal fistulas. Influence of previous repairs

The results of 81 endorectal flap advancements for simple rectovaginal fistulas are reported. Simple fistulas are defined as less than 2.5 cm in diameter, low or mid vaginal septum in location, and infectious or traumatic in origin. Essentially, the technique is advancement of a flap of mucosa, submucosa, and circular muscle over midline approximation of internal sphincter muscle. The mean patient age was 34 years old (range, 18 to 76 years). The causes were obstetrical injury (74 percent), perineal infection (10 percent), operative trauma (7 percent), and unknown (8 percent). Overall, the repair was successful in 83 percent of patients. Success correlated with the number of previous repairs, i.e., none: 88 percent success; one: 85 percent success; two: 55 percent success. There were 25 concomitant overlapping sphincteroplasty procedures. Only minor complications ensued, with no mortality. This repair is recommended for patients with no or one previous repair because of its lack of mortality, minimal morbidity, ease of concomitant sphincteroplasty, and avoidance of a colostomy. For patients with two or more earlier repairs, a muscle interposition should be considered.

Primary squamous cell carcinoma of the colon arising in a villous adenoma

The first case of pure squamous cell carcinoma arising in a villous adenoma of the cecum is reported, and the literature of squamous cell carcinoma of the colon is reviewed. The possible origin of this neoplasm in adenomas of the colon, similar to that of adenocarcinoma, is discussed, and the site distributions of adenocarcinoma and squamous cell carcinoma are compared. The distribution of primary colonic squamous cell carcinoma is found to be predominantly right-sided in comparison to adenocarcinoma (p less than 0.05). Although this result does not preclude adenomas as the origin of most squamous cell carcinomas, it suggests the influence of as yet unknown site-asymmetric factors that are different from those for adenocarcinoma.

Metachronous colorectal cancer. Time interval to presentation of a metachronous cancer

A retrospective review of 1888 colorectal cancer patients demonstrated 37 metachronous cancers in 30 patients for a metachronous cancer rate of 1.6 percent. Evaluation of the index cancers consisted of the traditional single-contrast barium enema and proctoscopic evaluation. Forty percent of the metachronous cancers appeared within two years of the index cancer. If the minimum length of the polyp-cancer sequence is three to five years, then this represents a failure of a traditional preoperative evaluation. A more sensitive evaluation potentially could decrease the metachronous cancer rate. Colonoscopy, which has been found to be more accurate in detecting synchronous neoplasms, should be included in the evaluation of all patients with colorectal cancers.