Recording forces exerted on the bowel wall during colonoscopy: in vitro evaluation

A novel system for distributed force measurement between the bowel wall and the shaft of a colonoscope is presented. The system, based on the piezoresistive method, involves the integration of soft miniature transducers to a colonoscope to enable a wide range of forces to be sensed. The attached sensing sheath does not restrict the propulsion of the colonoscope nor notably alter its flexibility. The addition of the sensor sheath increases the colonoscope diameter by 15-20% depending on the type of the colonoscope (adult or paediatric). The transducer's accuracy is +/-20 grammes if it is not subjected to extensive static forces. Under large static force conditions the errors may increase to +/-50 grammes. The tactile force measuring sensors have provided preliminary results from experiments on a model of the large bowel. The force measurements confirm the predictions on the location and magnitude of the forces and that most of the forces are exerted whilst the instrument is looping.     

Perforation of acquired small bowel diverticulum

A 77-year old woman was seen with an unusual pathologic entity after emergent abdominal exploration--a ruptured small bowel diverticulum. This patient had a known previous history of colonic diverticulosis when she had acute onset of severe abdominal pain. The patient underwent an exploratory laparotomy with resection of representative segments of small and large bowel. The large bowel had evidence of diverticulosis, while the small bowel resected segment had evidence of diverticulitis with rupture. An extensive review of the literature revealed a very small number of reported cases in the world literature (less than 150 cases). We reviewed the history of reported cases of ruptured and nonruptured small bowel diverticular disease, as well as this case.     

Perforation through small bowel malignant tumors

Data on 19 patients (6 women and 13 men) with malignancy perforation through small bowel tissue were retrospectively reviewed. The median patient age was 57 years (range, 41–81 years). The histopathology included lymphoma (seven patients), leiomyosarcoma (two patients), gastrointestinal stromal tumor (one patient), adenocarcinoma (one patient), metastatic carcinomas with unknown primary tumor (four patients), metastatic adenocarcinoma from the lung (one patient), and metastatic carcinomas from the hypopharynx (one patient), cervix (one patient), and lung (one patient). Resection of a segment of perforated bowel with primary anastomosis was performed in 16 patients, wedge resection of perforated lesion with plication in two patients, and loop ileostomy in one patient. Postoperative deaths occurred in 10 (52.6%) patients, owing to sepsis and organ functional failure. Seven patients died from the primary malignancy at a median follow-up of 6.5 months (range, 5 months to 1 year 9 months) after surgery. Moreover, two patients with small bowel lymphoma were alive with disease at 4 years 8 months and 7 years 1 month after surgery. In conclusion, perforation through small bowel malignant tumors had a high postoperative mortality rate. High index of suspicion of the disease with early surgical treatment may improve treatment outcomes. Supported by Chang Gung Memorial Hospital, Taiwan, under contract No. BMRP072.     

Changes in colonic motility during the development of chronic large bowel obstruction

The effect of chronic progressive distal large bowel obstruction on colonic motility was studied in six mini-pigs. Motility was detected in vivo during the development of obstruction with chronically implanted Ag/AgCl electrodes using an impedance technique. When the obstruction was complete the segments of bowel were resected and spontaneous contractile activity and response to cholinergic stimulation were studied in an organ bath. Any hypermotility resulting from obstruction was shortlived and a gradual state of hypomotility supervened proximal to the obstruction. Decompression of the bowel did not result in the immediate return of motility and the resected bowel was unresponsive to carbachol. These results suggest that spontaneous resolution of large bowel obstruction is unlikely and that motility disturbances are unlikely to be a cause of anastomotic dehiscence.     

Changes in intestinal blood flow during the development of chronic large bowel obstruction

The effect of chronic progressive distal large bowel obstruction on intestinal blood flow was studied in 12 mini-pigs. Blood flow was measured by the techniques of xenon133 clearance and intracardiac injections of radiolabelled microspheres. Intestinal blood flow was increased in the left colon and ileum but decreased in the caecum. Blood was shunted from the mucosa to the muscle layers. The results suggest that primary anastomosis of the obstructed left colon is not contraindicated by haemodynamic considerations.     

Injuries of the large bowel

An analysis of 120 patients with colonic injuries showed that minor injuries, especially if caused by penetrating trauma, can be treated satisfactorily by suturing without resorting to colostomy.     

Mechanical small bowel obstruction precipitated by colonoscopy

Mechanical small bowel obstruction (SBO) is rare complication of colonoscopy. We present a patient who developed SBO 24 h after surveillance colonoscopy. Four years prior to this procedure, he had undergone augmentation cecocystoplasty with continent ileal conduit. He subsequently underwent laparotomy and lysis of a band adhesion that caused extrinsic compression of the ileum proximal to ileotransverse colostomy. We further review the literature, describe the salient features of colononoscopy-induced bowel obstruction, and identify the risk factors for this unusual complication.