Tomoyuki Sato

Efficacy of magnifying endoscopy in the differential diagnosis of neoplastic and non-neoplastic polyps of the large bowel

PURPOSE: We have introduced magnifying colonoscopy into clinical practice and analyzed its diagnostic efficacy, especially regarding the ability to distinguish neoplastic from non-neoplastic polyps. METHODS: The materials consisted of 923 polyps. After identifying the lesions during normal colonoscopy, a dye was sprayed, and then the zoom apparatus of the colonoscope was used to make a magnified observation at a maximum 100 times magnification. We classified the crypt orifices into six categories and labeled them A to F as follows: A, a medium round appearance; B, an asteroid appearance; C, an elliptic appearance; D, a small, round appearance; E, a cerebriform appearance; F, no apparent structural appearance. RESULTS: Forty-two of 923 polyps did not reveal any clear images of crypt patterns. The percentage of histologically neoplastic change in the lesions classified as A, B, C, D, E, and F were 10, 15.9, 93.7, 100, 94.8, and 87.5 percent, respectively. When we considered types A and B to represent a crypt pattern of non-neoplastic lesions, and types C, D, E, and F to represent neoplastic lesions, and when the lesions that did not show any clear images were classified as a misjudgment, the diagnostic accuracy of neoplastic lesions (sensitivity) was 92 percent and that of non-neoplastic lesions (specificity) was 73.3 percent. Overall, the diagnostic accuracy in differentiating neoplastic from non-neoplastic lesions was 88.4 percent. Twenty-three neoplastic lesions that were misjudged to be non-neoplastic were histologically adenoma with mild atypia in 22 and adenoma with moderate atypia in 1. CONCLUSION: Magnifying colonoscopy was considered to be useful in determining the indications for colonoscopic removal.

Predictive factors for detecting colorectal carcinomas in surveillance colonoscopy after colorectal cancer surgery

PURPOSE: The aim of this study was to identify the high-risk groups for metachronous colorectal carcinoma among patients who undergo colorectal cancer surgery. METHODS: Three hundred forty-one patients undergoing colorectal cancer surgery who had undergone surveillance colonoscopy at least twice during a period of more than three years were analyzed. A metachronous colorectal carcinoma was defined as a new colorectal carcinoma detected by surveillance colonoscopy after surgery. RESULTS: Surveillance colonoscopy was performed 4.6 times per patient during an average of 6.2 years. Twenty-two metachronous colorectal carcinomas in 19 patients were detected, and 14 (64 percent) of 22 were detected within five years of surgery. The cumulative incidence of developing colorectal carcinomas during a five-year period was 5.3 percent. Seventeen (77 percent) of 22 carcinomas were 10 mm or less in size. Ten (71 percent) of the 14 carcinomas in early stages showed a flat appearance. Univariate analysis showed that extracolonic malignancy, coexistence of adenoma, and synchronous multiple colorectal carcinoma were significant predictive factors for detecting colorectal carcinomas in surveillance colonoscopy and that family history of colorectal carcinoma was a possible predictive factor. Multivariate analysis performed with Cox proportional hazards regression model showed that extracolonic malignancy and the coexistence of adenoma were significant predictive factors. CONCLUSION: We recommend that patients with the above predictive factors receive surveillance colonoscopy meticulously and regularly.

Variations in motor evoked potential latencies in the anal sphincter system with sacral magnetic stimulation

PURPOSE: The anal sphincter system of the skeletal musculature consists of various parts but functions as a single unit. The motor latencies measured at the puborectalis, deep external anal sphincter, superficial external anal sphincter, and subcutaneous external anal sphincter have yet to be clearly elucidated. This study was designed to measure the motor latencies of these sphincters separately and to investigate the electrophysiologic heterogeneity of the anal sphincter system. METHODS: In 20 preoperative patients with colon cancer without either neurologic or anorectal diseases, motor evoked potentials were taken separately bilaterally at levels measuring approximately 5, 3.8, 2.6, and 1.5 cm from the perineal skin using a concentric needle electrode after magnetic stimulation on the sacral region. These latencies were considered to be separately measured at the puborectalis, deep, superficial, and subcutaneous external anal sphincter. RESULTS: The motor latencies (median (95 percent confidence interval)) were 4.33 (4.1–4.93; right) and 4.24 (3.97–5.22; left) ms at the 5 cm level; 5.96 (5.45–7.32; right) and 6.44 (5.49–8.20; left) ms at the 3.8 cm level; 9.28 (7.99–11.21; right) and 8.88 (7.68–10.93; left) ms at the 2.6 cm level; and 11.06 (9.69–14.13; right) and 9.18 (8.09–10.31; left) ms at the 1.5 cm level. Significant differences were seen in the latencies between the 5 cm level and the other levels and between the 3.8 cm level and the other levels. CONCLUSIONS: The motor latencies in the anal sphincter system significantly varied depending on the distance from the skin. The latency may be shortest in the puborectalis and increasingly longer in the deep, superficial, and subcutaneous EAS, in that order.

Anal sphincter reconstruction with a pudendal nerve anastomosis following abdominoperineal resection: report of a case.

PURPOSE AND METHODS: We report herein a case of a patient with rectal carcinoma in whom a new anus was constructed following an abdominoperineal resection of the anorectum. This is the first reported case in which reconstruction of the anal sphincter was performed using the lower part of the gluteus maximus muscle with a pudendal nerve anastomosis. The pudendal nerve anastomosis maneuver was designed to achieve proper innervation and function of the external anal sphincter. This newly reconstructed sphincter was physiologically evaluated after surgery. RESULTS: The patients defunctioning colostomy was not closed following his initial surgery because part of the transposed muscle was devitalized by infection following blood flow damage. However, purposeful contraction of the new sphincter was easy to achieve without special training. The patients rectal sensation for the desire to defecate was satisfactory. Electromyographic studies demonstrated that the newly reconstructed anal sphincter had characteristics of the original external anal sphincter. CONCLUSIONS: This method is a promising procedure for reconstructing the anal sphincter.

Pelvic floor disturbance after childbirth

PURPOSE: Vaginal delivery disturbs pelvic floor innervation, which has previously been studied as a single mechanism. The effects of childbirth on innervation at different levels of the anal sphincter system were studied after childbirth. METHODS: Both anal manometry and motor latencies were measured in 67 females. Twenty-nine females (30.8±4.4 years) were examined four days after vaginal delivery. Eleven of these 29 females were re-examined five months after vaginal delivery. Nineteen females (33.6±4.6 years) who were examined five to nine days after undergoing an elective cesarean section and 19 asymptomatic, nonpregnant females (26.8±6.9 years) served as controls. Motor latencies were bilaterally measured within the anal sphincter system at 5, 3.8, 2.6, and 1.5 cm from the perineal skin by using a concentric needle electrode after sacral magnetic stimulation. Means of the bilateral latencies were analyzed. RESULTS: In postpartum females who gave birth vaginally, motor latencies at 5 and 3.8 cm, although not those at 2.6 and 1.5 cm, from the perineal skin were significantly prolonged, and anal pressure monitored by maximum resting and squeeze pressures was significantly decreased compared with that in control females. The decreased anal pressure normalized spontaneously. The prolonged motor latencies at the upper two levels of the anal sphincter system persisted in these females for five months after vaginal delivery. CONCLUSIONS: The disturbance of innervation of the upper anal sphincter system after vaginal delivery may last for a long time, whereas the decreased anal pressure normalizes in a short time. The protracted disturbance of innervation of the upper anal sphincter system may be associated with later development of fecal incontinence.

Prospective observation of small "flat" tumors in the colon through colonoscopy.

PURPOSE: No prospective observations of “flat” tumors of the colon have yet been reported. The purpose of this study was to investigate the progression of small flat tumors by prospective observations using colonoscopy. METHODS: The shapes of flat tumors were classified into three types, including slightly elevated lesions with a flat top (flat-top type), slightly elevated lesions with a wide depression in the center (wide-depressed type), and slightly elevated lesions with a slit-like depression in the center (slit-depressed type). A total of 14 flat tumors of the colon in 13 patients (2 women; median age, 58; range, 46–72 years) were examined in this project. All cases were followed up prospectively using colonoscopy, and all underwent a resection using the submucosal saline injection and snaring technique. RESULTS: Because two patients were eventually dropped from the follow-up, only 12 lesions were studied. The observation period ranged from 11 to 26 (median, 19) months. At the time the observations started, the diameter of the tumors varied from 2 to 6 (median, 4) mm, and the shapes were flat-top type in five lesions, wide-depressed type in three lesions, and slit-depressed type in four lesions. Of the 12 flat tumors, 8 showed various changes in their shape. However, only two lesions demonstrated an increase in diameter of the tumor from 2 to 4 mm. In the other ten tumors any change in size was less than 2 mm. No lesions were carcinomas according to the final histologic diagnosis, but all were adenomas. CONCLUSIONS: Flat tumors of the colon did not rapidly progress when they measured approximately 5 mm in diameter. Such flat tumors did tend to change their shapes; however, such changes did not indicate invasion to the submucosal layer.

Sacral Magnetic Stimulation for Pain Relief from Pudendal Neuralgia and Sciatica

AbstractINTRODUCTION: Magnetic stimulation of the sacral nerve roots is used for neurologic examination. However, no one has reported therapeutic efficacy of pain relief from pudendal neuralgia with sacral magnetic stimulation. METHODS: Five patients with pudendal neuralgia or sciatica received 30 to 50 pulsed magnetic stimuli of the sacral nerve roots. The median age of the patients was 59 (range, 28–69) years; there were 3 females. RESULTS: Sacral magnetic stimulation immediately eliminated the pain. The pain relief lasted between 30 minutes and 56 days (median, 24 hours). Adverse effects were not observed. CONCLUSIONS: This pilot study indicates that magnetic stimulation of the sacral nerve roots may be a promising therapeutic modality for pain relief from pudendal neuralgia and sciatica. Further studies should be performed to determine the appropriate intensity and frequency, as well as the utility of a second course, of magnetic stimulation treatment.

Pudendal nerve "complete" motor latencies at four different levels in the anal sphincter system in young adults.

AbstractPURPOSE: Pudendal nerve complete motor latency, or the sum of the conduction time from the root of the sacral nerve to the end of the pudendal nerve and the synaptic delay, varied in length (from shortest to longest) in the puborectalis, the deep external anal sphincter, and the superficial/subcutaneous external anal sphincter, in that order, for middle-aged people. The aim of this study was to elucidate whether such a phenomenon was physiologic or pathologic. METHODS: In 20 young adults (21.9 ± 1.37 years old, 10 females), pudendal nerve complete motor latencies were measured after magnetic stimulation to the sacral region. Electromyographic recordings were taken at depths of 5, 3.8, 2.6, and 1.5 cm from the perineal skin using a needle electrode and at 3 cm from the anal verge using surface electrodes within the anal canal. The data were compared with the data of the middle-aged cohort (65.4 ± 7.70 years old) in our previous study. RESULTS: The pudendal nerve complete motor latencies were 3.85 ± 1.24 ms at 5 cm, 3.97 ± 1.25 ms at 3.8 cm, 5.41 ± 2.42 ms at 2.6 cm, 9.98 ± 4.01 ms at 1.5 cm, and 3.45 ± 0.52 ms while using surface electrodes. The pudendal nerve complete motor latencies at 5, 3.8, and 2.6 cm were significantly shorter in the young adults than in the middle-aged subjects. The pudendal nerve complete motor latency using surface electrodes was significantly shorter than the pudendal nerve complete motor latency at 2.6 and 1.5 cm (mean ± standard deviation). CONCLUSIONS: Because pudendal nerve complete motor latency was progressively longer at 5, 3.8, 2.6, and 1.5 cm, in that order, in young adults as well as in middle-aged people, this phenomenon was considered to be physiologic and may be mechanically reasonable and safe in shutting the anal canal and might be useful for milking the residual mucus out of the anal canal to prevent soiling. Aging disturbed the innervation of the upper three levels of the anal sphincter system. Pudendal nerve complete motor latency using intra-anal surface electrodes approximated that at the highest of the anal sphincters.

Muscle change after anal sphincter reinnervation by a normal somatic peripheral nerve

INTRODUCTION: Pudendal neuropathy causes idiopathic fecal incontinence. We thus designed a new operation for idiopathic fecal incontinence based on the hypothesis that a conversion from innervation by the neuropathic pudendal nerve to that by the normal somatic peripheral nerve innervating a larger skeletal muscle might enable the anal sphincter to recover from neuropathic muscular atrophy. This study was undertaken to investigate the muscular change of the external anal sphincter after such an operation. METHODS: On 14 sides of eight dogs, the transected proximal end of the nerve innervating the biceps femoris muscle was microsurgically cross-transferred to the distal end of the transected pudendal nerve. The external anal sphincter was analyzed by electromyography and adenosine 5′-triphosphatase staining at three months after surgery. RESULTS: On 13 of 14 sides, the external anal sphincter was well preserved and the evoked potential was clearly recorded. The external anal sphincter in these dogs, however, had neither any basal electrical activity nor any increased electrical activity. The percentage of Type 1 muscle fibers of the external anal sphincter innervated by the nerve to the biceps femoris muscle (30.9±9.8 percent) was significantly higher than that of the normal external anal sphincter (15.2±8.5 percent;P<0.001) and also significantly lower than that of the normal biceps femoris muscle (38.5±7.5 percent;P=0.006). The diameter of the muscle fibers (Types 1 and 2) of the external anal sphincter (expressed as mean ± standard deviation) innervated by the nerve to the biceps femoris muscle (32.9±6.2 µm) was also significantly larger than that of the normal external anal sphincter (29.9±5.1 µm;P=0.021) and significantly smaller than that of the normal biceps femoris muscle (36.1±6.1 µm;P=0.028). CONCLUSIONS: The cross-nerve transfer procedure in a dog model was found to prevent muscular atrophy of the external anal sphincter when performed immediately after pudendal nerve transection.

Hirschsprung's disease in an adult patient with familial occurrence: report of a case.

Hirschsprung’s disease is almost always associated with newborns or infants; however, we report herein the unusual case of a 46-year-old woman in whom the symptoms of Hirschsprung’s disease emerged late in adult life. The involved rectosigmoid region was successfully removed by performing Duhamel’s operation with a diverting colostomy. After the colostomy was closed, she regained normal defecatory function. She had one male child affected by Hirschsprung’s disease of the total colon type who was operated on as a 12-month-old baby. The genetic predisposition of Hirschsprung’s disease has been reported, but its mode of inheritance has not yet been clarified. Moreover, most papers on the familial occurrence of this disease have reported that siblings were affected. Our patient was unique for the definite occurrence of the disease in successive generations. The features of Hirschsprung’s disease in adults and the familial occurrence are discussed with a review of the literature.