Shosaku Nakahara

Clinical and manometric evaluation of anorectal function following low anterior resection with low anastomotic line using an EEA stapler for rectal cancer.

Anorectal function was evaluated in eight patients who had low anterior resection of the rectum with a low anastomotic line, using an EEA™ stapler, with determination of function based on periodic manometric studies and clinical symptoms. Immediately following surgery all patients suffered from frequent bowel actions and soiling. These symptoms improved with time and most patients could enjoy almost normal daily life by the sixth postoperative month. One month after surgery, anal canal resting pressure and maximum squeeze pressure were significantly reduced and rectoanal inhibitory reflex was absent; neither showed a distinct tendency to improve thereafter. Rectal sensation and reservoir capacity, which also were seriously impaired, recovered satisfactorily by the time of the six-month examination. This suggests that an improvement of clinical symptoms following this operation is dependent upon the recovery of reservoir capacity and sensation of the neorectum, and that this operative procedure is a functionally acceptable option for low rectal cancer.

Effect of radiotherapy on anorectal function in patients with cervical cancer

PURPOSE The acute and long-term effects of pelvic radiation on defecation were studied. METHOD Anorectal function was assessed based on manometry and subjective symptoms in 31 patients with cervical cancer treated by radiotherapy alone. Sixteen of 31 patients were examined periodically before, during, and after radiotherapy (early group). Fifteen others were examined more than six months after completion of radiotherapy (late group). RESULTS One-third of patients in both groups had symptoms, mainly diarrhea and increased stool frequency. Patients in the late group also suffered from disturbed gas-stool discrimination, urgency, a sense of residual stool, and soiling. Anal canal resting pressure was significantly higher after radiotherapy (47 +/- 15.5 mmHg) than before radiotherapy (36.3 +/- 12.5 mmHg; P < 0.05). The maximum tolerable volume decreased with radiation, from 163.3 +/- 45 before to 119.2 +/- 41.4 ml during, 112.7 +/- 36.6 ml immediately after, and 94.6 +/- 34.4 ml in the late group (P < 0.01). Rectal compliance also decreased over time and was lower in the early group (before, 5.7 +/- 1.3 ml/mmHg; P < 0.01; during, 4.6 +/- 2.2 ml/mmHg, P < 0.01; after, 3.7 +/- 1.4 ml/mmHg; P < 0.05) than the late group (2.1 +/- 1.5 ml/mmHg) and lower before than after in the early group (P < 0.01). Although rectal pressure initiating continuous desire to defecate did not change, the maximum tolerable pressure was significantly higher in the late group (81 +/- 19.5 mmHg) than during (59 +/- 16.8 mmHg) or after (59.9 +/- 16.9 mmHg) radiotherapy in the early group (P < 0.05). CONCLUSION Radiation reduces the capacity of the rectal reservoir, even in asymptomatic patients. These changes develop during radiotherapy and progress over time.

Ileal adenomas in familial polyposis coli

We treated two patients with familial polyposis coli (FPC) who were found to have multiple adenomas in the ileostomy stoma, five and seven years after colectomy, respectively. These adenomas were dense and 3 to 10 mm in diameter. The adjacent ileal mucosa showed a colonic metaplasia. Ileal adenomas detected using intraoperative intestinal endoscopy at the time of colectomy were less than 2 mm in diameter and sparse in density. These findings suggest that ileal adenomas occurring after colectomy for FPC tend to increase in size and number and to resemble colonic adenomas.

COMPARISON OF BLOOD FLOW ASSESSMENT BETWEEN LASER DOPPLER VELOCIMETRY AND THE HYDROGEN GAS CLEARANCE METHOD IN ISCHEMIC INTESTINE IN DOGS

Blood flow of the colon and the ileum was measured before and after intestinal devascularization by laser Doppler velocimetry and the hydrogen gas clearance technique in 10 dogs in order to evaluate the clinical usefulness of laser Doppler velocimetry. The submucosal blood flow of the colon and the ileum measured by the hydrogen gas clearance method was significantly decreased, as was the subserosal blood flow of both sites measured by laser Doppler velocimetry. There was a linear relationship between the flow values using the two methods both in the colon (r = 0.7192, p less than 0.001) and in the ileum (r = 0.7646, p less than 0.001). These data suggested laser Doppler velocimetry may be a useful method to assess the degree of intestinal ischemia because of its noninvasiveness and good correlation with submucosal blood flow by the hydrogen gas clearance technique.

Gallstone formation and gallbladder bile composition after colectomy in dogs

A high prevalence of gallstones has been described in patients following colectomy. The aim of this study was to examine whether lithogenicity is attributed to colectomy. In the present study, changes in gallbladder bile composition and the mechanism of gallstone formation after colectomy were examined in dogs. Ten mongrel dogs underwent restorative proctocolectomy. Seven dogs which received sham operations served as controls. Over a 12-week postoperative period, samples of gallbladder bile, formed gallstones and serum were collected and analyzed. In 7 of the 10 (70%) colectomized dogs, gallstones were found in the gallbladder, while the control dogs had no stones. Macroscopically the gallstones were similar to black pigment stones observed in humans. Chemical analysis and Fourier transform-infrared spectroscopy examination revealed that the stones were composed mainly of sodium bilirubinate and proteins, with minor amounts of calcium salts and cholesterol. Significant increases in biliary pH and concentrations of ionized calcium and unconjugated bilirubin were observed in the gallbladder bile of the colectomy group compared with that of the control group. The total bile acid and total bilirubin concentrations were significantly decreased in the colectomy group. Cholesterol crystal nucleation did not occur. The inhibitory effect of gallbladder bile on calcium carbonate precipitation in anin vitro assay system was preserved even after colectomy. In conclusion, proctocolectomy increases the concentration of unconjugated bilirubin in gallbladder bile and induces pigment gallstones which are composed mainly of sodium bilirubinate and proteins since calcium ions and cholesterol are stabilized in dogs.

Regional difference in intestinal adaptation after total colectomy as judged by the changes of mucosal Na-K ATPase, cyclic AMP, and transmural potential difference.

Intestinal adaptation and its regional difference after total colectomy were investigated in dogs by measuring mucosal Na−K ATPase, cyclic AMP, and transmural electric potential difference (PD). Twenty-four weeks after the total proctocolectomy, Na−K ATPase activity and PD increased significantly in all intestinal sites, whereas cyclic AMP showed no significant changes. The regional difference in the remaining intestine was examined in the jejunum, ileum, and interposed jejunum (neorectum). Na−K ATPase activity showed no significant regional difference, but the largest increase was found to occur in the ileum. PD also increased markedly in the ileum and there was significant difference between the ileum and other intestinal sites. These facts suggest that the increased active ion transport mediated by mucosal Na−K ATPase and transmural PD in the ileum is closely related to the intestinal adaptation occurring after total colectomy and indicates a greater potential of the ileum for adaptive compensation than either jejunum or neorectum.

Bile composition after total proctocolectomy with interposed jejunal segment as neorectum

Changes of bile composition in gallbladder bile and serum chemistries were investigated in nine dogs after proctocolectomy and ileoanal anastomosis, using an interposed jejunal segment as a neorectum. A significant decrease in cholic acid and an increase in deoxycholic acid were observed 24 weeks after the operation, although there was no significant change of total bile acid and phospholipids in the bile. Concentration of cholesterol and cholesterol saturation index in bile increased after total proctocolectomy. Although serum triglyceride levels became lower compared with the nontreated control group, concentrations of total protein, serum cholesterol, total lipids, blood sugar, and electrolytes showed no significant difference. This operative procedure apparently did not impair intestinal absorption of bile acid, but did increase the biliary cholesterol saturation index.

Anorectal function after high sacrectomy with bilateral resection of S2–S5 nerves

A 19-year-old man underwent resection at the S1–S2 interspace with sacrifice of bilateral sacral nerves below S2 for a sacral tumor. The postoperative anorectal function was evaluated periodically for one year using manometry and subjective findings. The rectoanal inhibitory reflex was intact, whereas a disturbance of anorectal sensation, a loss of anal squeeze pressure, a decrease of anal canal resting pressure, urinary incontinence, and impotency were apparent. These findings suggest that sacrifice of bilateral sacral nerves below S2 leads to a feeble anal canal basal tone with the rectoanal inhibitory reflex, and that a significant impairment of anorectal function is inevitable.

Effect of peptide YY on intestinal and hepatic blood flow in dogs

Objective: To investigate the effect of peptide YY (PYY) on the flow of splanchnic blood and bile in dogs. Methods: Under general anaesthesia, the dogs received porcine PYY at doses of 100, 400, or 800 pmol/kg/h for 1.5h. Blood flow was measured in the subserosa of the jejunum, ileum, and colon as well as in the liver, using the hydrogen gas clearance method, before, during, and after PYY infusion. Choledochal bile was collected and its volume measured. Results: Colonic blood flow was significantly inhibited by 100, 400, and 800 pmol/kg/h PYY compared with the pre-infusion levels (P<0.05, P<0.05, and P<0.01, respectively). It was also inhibited by 800 pmol/kg/h PYY (P< 0.05) compared with the non-infusion group. Jejunal blood flow was significantly decreased by 800 pmol/kg/h of PYY (P<0.01), while ileal blood flow was decreased by 100pmol/kg/h of PYY (P<0.05). PYY did not change hepatic blood flow, but inhibited bile flow in a dose-dependent manner. Conclusions: These data show that PYY has an inhibitory effect on intestinal blood flow and varying regional effects. PYY does not affect hepatic blood flow; its inhibitory effect on bile flow is therefore probably not the result of decreased hepatic perfusion.

Manometric and Histologic Assessment following Proctocolectomy and Straight Enteroanal Anastomosis in Canines

Serial manometric studies were performed in mongrel dogs before and after total colectomy, mucosal proctectomy and interposed jejunoanal anastomosis without pouch. Fecal continence and body weight gain were clinically satisfactory by 28 weeks after surgery. Even at 28 weeks after the mucosal proctectomy, the mean maximal resting anal sphincter pressure was significantly lower than the preoperative level (p less than 0.001). Neorectal compliance also decreased. The rectoanal inhibitory reflexes were not observed 2 weeks after the mucosal proctectomy but atypical to typical patterns gradually appeared up to 28 weeks following the mucosal proctectomy. Histologic examination showed no injury of anal sphincter muscles. Mild inflammation was found in the neorectal mucosal layer in all animals. Meissners plexus in rectal muscular cuff was almost completely disrupted. These data suggested that there is certain limitation in restoration of anoneorectal function after mucosal protectomy and enteroanal anastomosis, though with gentle and careful operations.