摘要:

&NA;Hyperplastic polyps have traditionally been regarded as nonneoplastic polyps lacking malignant potential. The demonstration of genetic alterations within these lesions indicates an underlying neoplastic cause. There is evidence that hyperplastic polyps are heterogeneous. Most are innocuous, but subsets may have malignant potential. Risk factors for neoplastic progression include multiple, large, and proximally located polyps. Aberrant methylation resulting in the silencing of cancer genes may be an important underlying mechanism, particularly in pathways progessing to tumors with DNA microsatellite instability. Lesions intermediate between hyperplastic polyp and cancer include admixed polyps and serrated adenomas. Currently, pathologists have different thresholds for diagnosing serrated adenomas, including the distinction from large hyperplastic polyps. Reasons for over looking this pathway in the past may include rapid tumor progression and the fact that proximally located hyperplastic polyps may be flat and not especially numerous. Management of the serrated pathway of colorectal neoplasia may require novel approaches to screening, early detection, and prevention.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

PURPOSE:The aim of this controlled study was to examine whether it was feasible to use magnetic stimulation as a new diagnostic tool to evaluate the motor function of the sacral roots and the pudendal nerves in patients with fecal incontinence.PATIENTS AND METHODS:Nineteen consecutive patients (17 females) with a median age of 67 (range, 36‐78) years referred for fecal incontinence and 14 healthy volunteers (six females) with a median age of 42 (range, 23‐69) years were examined. Latency times of the motor response of the external anal sphincter were measured after electric transrectal stimulation of the pudendal nerve and magnetic stimulation of the sacral roots.RESULTS:The success rates of pudendal nerve terminal motor latency and sacral root terminal motor latency measurements were 100 and 85 percent, respectively, in the control group and 94 and 81 percent, respectively, in the fecal incontinence group. Median left pudendal nerve terminal motor latency was 1.88 (range, 1.4‐2.9) milliseconds in the control group and 2.3 (range, 1.8‐4) milliseconds in the fecal incontinence group (P<0.006). Median right pudendal nerve terminal motor latency was 1.7 (range, 1.3‐3.4) milliseconds in the control group and 2.5 (range, 1.7‐6) milliseconds in the fecal incontinence group (P<0.003). Median left sacral root terminal motor latency was 3.3 (range, 2.1‐6) milliseconds in the control group and 3.7 (range, 2.8‐4.8) milliseconds in the fecal incontinence group (P<3 0.03). Median right sacral root terminal motor latency was 3 (range, 2.6‐5.8) milliseconds in the control group and 3.9 (range, 2.5‐7.2) milliseconds in the fecal incontinence group (P=0.15).CONCLUSIONS:Combined pudendal nerve terminal motor latency and sacral root terminal motor latency measurements may allow us to study both proximal and distal pudendal nerve motor function in patients with fecal incontinence. Values of sacral root terminal motor latency have to be interpreted cautiously because of the uncertainty about the exact site of magnetic stimulation and the limited magnetic field strength.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

PURPOSE:After curative surgery for rectal cancer, patients with pelvic recurrence may undergo curative surgical resection. We determined whether salvage surgery in appropriately selected patients could significantly lengthen disease‐free survival time and if so what factors predicted this outcome.METHOD:We reviewed the records of all patients treated for rectal cancer at our institution between 1980 and 1993. Of 937 patients who underwent surgery with curative intent after proctectomy or transanal local excision, 81 (8.6 percent) experienced local recurrence. During the same period 36 patients with locally recurrent rectal cancer were referred from other institutions. Logistic regression analysis was used to identify predictors of salvage surgery. The Kaplan‐Meier method was used to estimate cancer‐specific and disease‐free survival times in 43 patients who underwent salvage surgery. The Cox proportional hazard model was used to identify factors associated with these outcomes.RESULTS:Of 117 patients with locally recurrent rectal cancer, 43 (36.7 percent) underwent salvage surgery. Factors associated with higher chance of receiving salvage surgery were female gender, the first operation performed at outside institutions, and transanal local excision as the initial operation. For 43 patients who underwent salvage surgery, five‐year cancer‐specific and disease‐free survival rates were 49.7 and 32.2 percent, respectively. No factors were significantly associated with death caused by cancer. However, a trend for poor prognosis was observed in patients with recurrence diameter >3 cm and tumor fixation Degree 2.CONCLUSION:Salvage surgery for properly selected patients with locally recurrent rectal cancer allows long‐term palliation and significantly lengthens disease‐free survival.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

PURPOSE:Total abdominal colectomy with ileorectal anastomosis has been the procedure of choice for patients with the established diagnosis of colonic inertia. Previous studies with a limited follow‐up of only one to two years have shown acceptable results and a high rate of patient satisfaction. The aim of this study was to evaluate the long‐term results of total abdominal colectomy in these patients in terms of complications, bowel function, and overall patient satisfaction.METHODS:Access to the colorectal registry at the Cleveland Clinic Florida identified all patients who underwent total abdominal colectomy for colonic inertia between 1988 and 1993, with a minimum of five‐year follow‐up. Telephone interviews were designed to assess bowel function, concomitant use of any antidiarrheal medications, postoperative complications, persistence or development of preoperative symptoms such as pain or bloating, and overall satisfaction. Patients were asked to rate their outcome as excellent, good, fair, or poor.RESULTS:Fifty patients underwent total abdominal colectomy for the diagnosis of colonic inertia. Three patients died of unrelated causes and 30 (60 percent) were available for follow‐up. The mean follow‐up was 106 months, ranging from 61 to 122 months. All 30 patients reported the outcome of surgery as “excellent.” The average frequency of spontaneous bowel movements was 2.5 (range, 1‐6) per day. During the period of follow‐up, six patients (20 percent) required admission for small‐bowel obstruction, three of whom (10 percent) required laparotomy. Four patients complained of mild pelvic pain, only one of whom had the onset of pelvic pain postoperatively that persisted until the time of interview. In the other three patients the pain was present preoperatively but had decreased in intensity since the operation. Two patients (6 percent) still required assistance with bowel movements, one by laxatives and the other by enemas. Only two patients (6 percent) needed antidiarrheal medications to reduce bowel frequency.CONCLUSION:This long‐term follow‐up revealed a high degree of patient satisfaction and very good bowel habits, with an acceptable long‐term rate of bowel obstruction. Based on these results, total abdominal colectomy can be recommended to patients with well‐established colonic inertia with expectations of sustained benefit up to ten years after surgery.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BACKGROUND:Total anorectal reconstruction with dynamic graciloplasty is an alternative to a permanent colostomy; however, perfect continence cannot be achieved because of loss of sensitivity. This study was designed in dogs to determine whether monitoring of rectal electric impedance can give information about fullness or motility of the rectum.METHODS:Four adult female begale dogs underwent rectal electric impedance measurements using a bipolar electrode implanted on the rectal wall. An alternating current of 1&mgr;A at a frequency of 4 kHz was applied between the two wires. Variations of impedance (called impedance waves), defecations, and weight of stools were recorded and analyzed.RESULTS:The basal rectal impedance was 682±19 &OHgr;. During the period of observation (n=4), 84 impedance waves (amplitude, 72±2 &OHgr;; duration, 58±11 minutes) were observed and 33 defecations (weight of stools, 74±6 g) occurred. Four types of impedance waves were identified and classified into two groups: low‐amplitude or short‐duration waves (Types I, II, and III), and high‐amplitude and long‐duration waves (Type IV). Frequency of defecation was associated with the amplitude of the waves. The weight of stools was correlated with the duration of the waves (r=0.574, n=27,P=0.002). Types I, II, and III waves were correlated with eventual partial defecations, whereas Type IV waves were correlated with complete defecations. After defecation, no spontaneous new defecation occurred before recovering at least 80 percent of the basal impedance.CONCLUSIONS:Rectal impedance variations are correlated with defecation in a canine model, and single bipolar measurements provide a suitable evaluation of rectum fullness. This suggests the possible use of impedance signals to control electrostimulated graciloplasty after anorectal reconstruction.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

PURPOSE:The aim of this study was the development of a procedure which would successfully treat selected patients presenting with incapacitating urgency and fecal incontinence. Some patients presenting with urgency and fecal incontinence, with an intact anorectum but deficient sphincter mechanism, have low rectal compliance. Management is problematic, because correction of the sphincter defect does not abolish the incapacitating urgency caused by rectal hypersensitivity.METHODS:This was a prospective study of three female patients with urgency and fecal incontinence who underwent combined rectal augmentation using a segment of distal ileum and stimulated gracilis anal neosphincter. All patients had low rectal volumes and two exhibited a temporal relationship between high‐amplitude (>60 mmHg) rectal pressure waves and urgency on prolonged ambulatory anorectal manometry.RESULTS:Urgency was abolished and continence restored in all individuals. When the level of stimulation was not optimal or had been discontinued, patients experienced only passive incontinence with no urgency. Postoperative physiology revealed elevated thresholds to rectal distention and a reduction in the number of high‐amplitude rectal pressure waves in all cases.CONCLUSIONS:Combined rectal augmentation with stimulated gracilis anal neosphincter may be of benefit to some patients with distressing urgency and fecal incontinence not previously helped by current techniques.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

INTRODUCTION:Compliance is defined as the change in volume or cross‐sectional area divided by the change in pressure. Pressure‐volume measurement during distention with a compliant balloon is the most commonly used method for computation of rectal compliance. However, intraindividual and interindividual variations are large, restricting the usefulness of the method. Other methods such as rectal distention by a large, noncompliant bag and rectal impedance planimetry for assessment of pressure‐cross‐sectional‐area relations have been proposed as alternatives owing to the reduction of errors from elongation of the balloon within the rectal lumen. However,in vivoreproducibility of pressure‐volume measurement during distention with a compliant balloon, pressure‐volume measurement during rectal distention by a large, noncompliant bag, and rectal impedance planimetry have never been compared.PURPOSE:The aim of this study was to comparein vivoreproducibility of the above‐mentioned methods and to study theirin vitroreproducibility and validity.METHODS:Ten healthy volunteers (six men) aged 21‐59 years were randomized to either rectal pressure‐volume measurement with a compliant balloon or rectal impedance planimetry. After a one‐hour rest, the other procedure was performed. After two weeks, both procedures were again performed in the same order. During rectal impedance planimetry the volume of the bag used (maximum volume 450 ml; secured at both ends to the probe) was continuously registered, measuring pressure‐volume relations during rectal distention by a large, noncompliant bag. Reproducibility was tested by comparing the difference divided by the mean for each method at eight pressure steps in the range from 5 to 40 cm H2O. Furthermore, thein vitroreproducibility and validity of the three methods were studied using polyvinyl chloride tubes with known cross‐sectional areas.RESULTS:In vivoreproducibility for pressure‐volume measurement with a large, noncompliant bag and rectal impedance planimetry was significantly better than for pressure‐volume measurement with a compliant balloon (P=0.005 andP=0.019, respectively). No statistically significant difference was found between pressure‐volume measurement with a large, noncompliant bag and rectal impedance planimetry (P=0.20).In vitroreproducibility of pressure‐volume measurement with a large, noncompliant bag and rectal impedance planimetry was good, but some elongation occurred, reducing the validity of pressure‐volume measurement with a large, noncompliant bag. Coiling and elongation of the balloon within the lumen were major sources of error for pressure‐volume measurement with a compliant balloon.CONCLUSION:In vivoandin vitroreproducibility of methods used for measurement of rectal compliance can be improved by restricting the effects of elongation within the lumen either by using a large‐volume, noncompliant bag or by rectal impedance planimetry. However, pressure‐volume measurement will to some degree depend on the properties of the balloons or bags.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

PURPOSE:The need for a conversion is a problem inherent in laparoscopic surgery. The present study points up the significance of conversion for the results obtained with laparoscopic colorectal surgery and identifies the risk factors that establish the need for conversion.METHOD:The study took the form of a multicentric, prospective, observational study within the Laparoscopic Colorectal Surgery Study Group. A total of 33 institutions in Germany, Austria, and Switzerland participated. The study period was 3.5 years. Cases were documented with the aid of a standardized questionnaire.RESULTS:Within the framework of the Laparoscopic Colorectal Surgery Study Group, a total of 1,658 patients were recruited to a multicenter study over a period of three and one‐half years (from August 1, 1995 to February 1, 1999). The observed conversion rate was 5.2 percent (n=86). The patients requiring a conversion were significantly heavier (body mass index, 26.5vs.24.9) than those undergoing pure laparoscopy. Resections of the rectum were associated with a higher risk for conversion (20.9vs.13 percent). Intraoperative complications occurred significantly more frequently in the conversion group (27.9vs.3.8 percent). The duration of the operation was significantly increased after conversion in a considerable proportion of the procedures performed. Postoperative morbidity (47.7vs.26.1 percent), mortality (3.5vs.1.5 percent), recovery time, and postoperative hospital stay were all negatively influenced by conversion, in part significantly. Institutions with experience of more than 100 laparoscopic colorectal procedures proved to have a significantly lower conversion rate than those with experience of fewer than 100 such interventions (4.3vs.6.9 percent).CONCLUSION:Although, of itself, conversion is not considered to be a complication of laparoscopic surgery, it is true that the postoperative course after conversion is associated with appreciably poorer results in terms of morbidity, mortality, convalescence, blood transfusion requirement, and postoperative hospital stay. The importance of experience in laparoscopic surgery can be demonstrated on the basis of the conversion rates. Careful patient selection oriented to the experience of the surgeon is required if we are to keep the conversion, morbidity, and mortality rates of laparoscopic colorectal procedures as low as possible.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

PURPOSE:The purpose of this review was to define the learning curve for laparoscopic colorectal resections.METHODS:A prospectively accumulated, computerized database of all laparoscopic colorectal resections performed by three surgeons between April 1991 and March 1999 was reviewed.RESULTS:A total of 461 consecutive resections were evenly distributed among three surgeons (141, 155, and 165). Median operating time was 180 minutes for Cases 1 to 30 in each surgeon's experience and declined to a steady state (150‐167.5 minutes) for Cases 31 and higher. Subsequently, Cases 1 to 30 were considered “early experience,” whereas Cases 31 and higher were combined as “late experience” for statistical analysis. There were no significant differences between patients undergoing resections in the early experience and those undergoing resections in the late experience with respect to age, weight, or proportion of patients with malignancy, diverticulitis, or inflammatory bowel disease. There were greater proportions of males (42vs.54 percent,P=0.046) and rectal resections performed (14vs.32 percent,P=0.002) in the late experience. Trends toward declining rates of intraoperative complications (9vs.7 percent,P=0.70) and conversion to open surgery (13.5vs.9.7 percent,P=0.39) were observed with experience. Median operating time (180vs.160 minutes,P<0.001) and overall length of postoperative hospital stay (6.5vs.5 days,P<0.001) declined significantly with experience. There was no difference in the rate of postoperative complications between early and late experience (30vs.32 percent,P=0.827).CONCLUSIONS:The learning curve for performing colorectal resections was approximately 30 procedures in this study, based on a decline in operating time, intraoperative complications, and conversion rate. Learning was also extended to clinical care because it was appreciated that patients could be discharged to their homes more quickly.

ISSN:0012-3706    

出版商:OVID    

年代:2001

数据来源: OVID