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Biomedical subjects

R R Dozois

Publications and source records attributed to R R Dozois.

At least 145 records · Page 8Linked to original sources
PubMed1982

Prostaglandin generation from gastroduodenal mucosa: regional and species differences.

Regional and species differences in prostaglandin synthesis from gastroduodenal mucosa were assessed radiometrically. In the presence of excess added arachidonic acid substrate, corporal mucosa generated more prostanoid product per DNA than did antral or duodenal mucosa whether the whole homogenate or the microsomal fraction was used as an enzyme source. This appeared to be secondary to variability in cyclooxygenase activity and could not be explained by regional differences in the activity of enzymes competing for arachidonic acid substrate, in free endogenous arachidonic acid levels, in prostaglandin catabolizing activity, or in homogenate inhibitors. The qualitative product profile differed between species but not between regions within a species.

Animals↗
PubMed1982

Endorectal ileoanal anastomosis.

In 1933, Nissen performed the first ileoanal anastomosis. Since then, ileoanal anastomosis has enjoyed only periodic popularity because numerous postoperative problems, primarily as a result of infection and incontinence, plagued the procedure. In recent reports, however, better postoperative results have been detailed which stem not only from improved surgical technique and better selection of patients but also from increased understanding of the physiologic mechanisms by which fecal continence is achieved. At operation, meticulous hemostasis and asepsis, accurate en bloc mucosal dissection and effective drainage each contribute to good functional results and the minimization of complications. In addition, patients who manifest evidence of dysfunction of anal sphincters, who are elderly or obese or who have Crohn's disease should not be candidates for ileoanal anastomosis. Finally, if the anal sphincters are intact, reliable ileal reservoir function, achieved by passive dilation, balloon distention or surgical construction of a pouch, may be the most important determinate of excellent clinical results after ileoanal anastomosis.

Adult↗
PubMed1982

Primary closure and continuous irrigation of the perineal wound after proctectomy.

The aim was to assess the success of primary closure and continuous irrigation of the perineal wound in achieving wound healing after proctectomy. The frequency and degree of primary healing (dry wound within 30 days after removal of irrigation catheters) and the factors affecting the rate of healing were determined in 152 patients undergoing proctectomy for carcinoma (31 patients), Crohn's colitis (32 patients), or ulcerative colitis (89 patients). All patients were followed for at least 2 years. Primary healing occurred in 64.5% of patients, whereas it was delayed (dry wound by 90 days) or failed to occur in 30.2% and 5.3%, respectively. Of those with carcinoma, 87% had healing by 30 days, whereas only 61% and 50% of those with either ulcerative colitis or Crohn's disease, respectively, had healing in that time (P less than 0.02). Females had primary healing more often than males (70% versus 45%, P less than 0.01), and the incidence of persistent perineal sinus was greater in men (28%) than in women (13%) (P less than 0.05). Primary healing was adversely affected in men when drains exited centrally through the wound (31% healed primarily) as opposed to when they exited laterally (65% healed primarily, P less than 0.04). We conclude that primary closure with irrigation of the perineal wound is safe and provides satisfactory healing in most patients.

Adolescent↗
PubMed1982

Ileoanal anastomosis in the adult.

Of 50 adults with chronic ulcerative colitis, familial polyposis or Crohn's disease undergoing colectomy, excision of the rectal mucosa, endorectal ileoanal anastomosis and protective proximal ileostomy, 42 subsequently had restoration of fecal continuity. Observation for six to 36 months revealed that anastomotic strictures or fecal urgency and frequency developed in 13 of the 42 patients. Most of these patients had undergone operation early in the series. All 13 patients required abandonment of the neorectum. Thirty of 39 evaluable patients were continent, averaged eight bowel movements per day and could distinguish between gas and stool. Thirty patients preferred life with an ileoanal anastomosis to that with an ileostomy. We concluded that ileoanal anastomosis is a viable alternative for some adults requiring proctocolectomy.

Adult↗
PubMed1981

Factors affecting revision rate after continent ileostomy.

Our aim was to determine factors that may predispose to malfunction of a continent ileostomy. Among 299 patients who underwent continent ileostomy and were followed up for at least one year, the need for revision of the ileostomy was compared by sex, age, type of initial operation, and type of revision. Revision was required less often in females, younger patients, and patients undergoing proctocolectomy and continent ileostomy. However, the rate of subsequent revision was similar after the two types of repair (repair of old valve vs construction of new valve). Constructing a continent ileostomy in stages is not necessary; patients undergoing proctocolectomy and continent ileostomy required fewer revisions than did those who had a Brooke ileostomy prior to their continent ileostomy. Moreover, a malfunctioning valve should be revised rather than a new one created; revision was technically simpler and gave comparable results.

Adolescent↗
PubMed1981

Hartmann's procedure. Its use with complicated carcinomas of sigmoid colon and rectum.

We assessed the safety of Hartmann's procedure in terms of postoperative morbidity and mortality associated not only with the original operation, but also with reestablishment of colorectal continuity and long-term survival. We studied 107 consecutive patients in whom Hartann's procedure was performed either electively (96) or as an emergency (11) between 1970 and 1975. In 87, the resection extended below the peritoneal reflection. The mean age of the patients was 67 years. The principal indication for Hartmann's procedure was palliation (53%), obstruction (42%) either alone or with perforation, and technical difficulties (5%). Four patients died (3.7%) in the immediate postoperative period, two after elective surgery (2.1%). Complications were observed in 35 patients, including wound infection or dehiscence (22), urinary tract problems (seven), and pelvic abscess (three). Colorectal continuity was reestablished in ten patients without mortality or morbidity. The mean five-year survival for Dukes' B, C, and D lesions was 54%, 23%, and 3%. Hartmann's procedure, when performed for complicated carcinomas of sigmoid colon and rectum, including subsequent restoration of bowel continuity, is safe and can be associated with long-term survival.

Adult↗
PubMed1981

Does Peutz-Jeghers syndrome predispose to gastrointestinal malignancy? A later look.

Several reports have recently suggested an association between the development of intestinal carcinoma and the presence of Peutz-Jeghers syndrome. During the 45-year period between 1935 and 1979, 48 patients with Peutz-Jeghers syndrome were seen at the Mayo Clinic, Rochester, Minn, and followed up for a median period of 33 years. Carcinoma of the small or large intestine did not develop in any patient, with possibly one exception. Survival of patients with Peutz-Jeghers syndrome also was found to be similar to that of the general population. Therefore, skepticism continues about the premalignant potential of this rare syndrome, especially in the small intestine, and surgical conservatism should be practiced in its management.

Adult↗
PubMed1981

Interdigestive canine pancreatic juice composition and pancreatic reflux and pancreatic sphincter anatomy.

Canine and human exocrine pancreatic secretion into the duodenum during fasting is cyclical and related to intestinal motility. To characterize the composition of pure pancreatic juice during the cyclically recurring sequence of propagated motor events (interdigestive motor complex) and to establish whether pancreatic reflux occurs, dogs were prepared with three permanent indwelling duodenal catheters and a pancreatodochal cutaneous catheter. The duodenal catheters were used to record duodenal pressures and measure pancreatic secretion of trypsin, lipase, and bicarbonate, based on the recovery of a constantly perfused marker, [14C]PEG. Pancreatic duct pressures or pancreatic juice concentrations of [14C]PEG, trypsin, lipase, or bicarbonate (done separately in each of five dogs throughout one interdigestive cycle on 4 different days) were related to duodenal motor activity. Finally, the pancreatic duct orifice of freshly sacrificed dogs was examined by light and electron microscopy. During fasting, (1) pancreatic volume secretion increased 10-fold during phases II, III, and IV (P less than 0.001), and bicarbonate concentration increased during phases III and IV (P less than 0.05) compared with phase I, while trypsin and lipase concentrations did not change; (2) reflux of duodenally perfused [14C]PEG into the pancreatic duct occurred in two of five dogs and was minimal (less than 0.1%); and (3) a positive mean pressure gradient from duodenum to pancreatic duct occurred only during phase III (7.4 +/- 4.1 cm H2O). Anatomic studies of the pancreatic duct opening showed a specialized papillary mucosa and an independent crescentic sphincter muscle. We conclude that during fasting, pancreatic juice composition is intimately linked to the different phases of interdigestive intestinal motor activity and that an efficient antireflux mechanism exists.

Animals↗
PubMed1981

Radical pancreatoduodenectomy--a procedure to be abandoned?

Radical pancreatoduodenectomy, or Whipple's procedure, has gradually fallen into disrepute during the past decade. This loss of popularity has resulted from excessive postoperative mortality and morbidity due to inherent technical difficulties, the dismal long-term survival when the procedure is done for adenocarcinoma of the pancreas, and the current enthusiasm for total pancreatectomy. Our objective was to assess the technical aspects of the Whipple procedure as they relate to subsequent morbidity and mortality. Conclusions are drawn from the evaluation of 146 consecutive patients who underwent this procedure between 1970 and 1979 for either benign (10 patients) or malignant (136 patients) diseases of the pancreas and periampullary region. The postoperative mortality was 4.1%. Significant morbidity occurred in 34% of patients, and early reoperation was required in 7.5% of these patients. The median postoperative hospital stay was 19 days. The relatively low postoperative mortality indicates that inherent technical difficulties of the Whipple procedure can be overcome and supports its continued use in carefully selected patients. The persistent high morbidity and the rather poor long-term results following treatment of certain pancreatic malignancies place individual surgical judgment and technical expertise at a premium when ever this classic operation is contemplated.

Adenocarcinoma↗
PubMed1980

Inhibition of histamine-sensitive adenylate cyclase from guinea pig fundic gastric mucosa by arachidonic acid and by an analog of prostaglandin endoperoxide PGH2.

The effects of prostaglandin precursors, namely an analog of prostaglandin endoperoxide PGH2 [(15S)-hydroxy-9 alpha,11 alpha-(epoxymethano)prosta-5,13-dienoic acid] and arachidonic acid, were assessed on gastric adenylate cyclase activity from cell-free preparations of guinea pig fundic mucosa. The two precursors were tested against basal adenylate cyclase activity and that simulated by histamine (10(-4) M), by PGE2(10(-4) M), by 5

Adenylyl Cyclase Inhibitors↗
PubMed1980

Surgical management of inflammatory bowel disease.

Indications for operation in patients with inflammatory bowel disease are now standardized as a result of the vast surgicaL experience that has been accumulated during the past 40 years. The surgical indications in Crohn's disease and chronic ulcerative colitis vary minimally with the anatomic distribution of either disease, and can be recognized easily in a particular patient. Consequently, decision or judgment regarding the need for operation is rarely difficult. Delaying operation on the basis of fear of recurrence of Crohn's disease is unrealistic because (1) indications for operation are complications of the disease that have not responded or cannot be expected to respond to medical treatment, (2) conservative resection primarily removes diseased bowel that will never return to normal, (3) many patients, perhaps 50%, will never have recurrence of disease, and (4) those who have recurrence will have experienced varying periods when they were free of disease and relieved of the serious complications for which their operations were performed. The value of surgery in the treatment of patients with chronic ulcerative colitis can be stated even more positively, because recurrence of disease is never a concern after proctocolectomy.

Adult↗
PubMed1980

Improved results with continent ileostomy.

The objective of this study was to determine if recent technical modifications have improved our results with continent ileostomy (Kock pouch). The modifications were that the valve of the pouch was made at least 5 cm in length and was anchored with specially placed, nonabsorbable sutures or staples. The pouch was drained continuously for the first four postoperative weeks, after which it was only gradually allowed to expand. Results from our first 149 patients were compared to those from our last 150 patients, in whom the modified approach was used. The age, sex, indications for operation and types of operation were similar in the early and late groups. No postoperative deaths occurred, and the incidence of continence at dismissal from hospital was near 100% in both groups. However, 15 pouches were excised in the early group as opposed to only five in the late group (p < 0.01). Moreover, the need for revision of the valve by one year was 43% in the early group but only 22% in the late group (p < 0.001). Long-term follow-up showed that complete continence was present in 60% of patients in the early group and 75% of patients in the later group (p < 0.05), although only about 5% of patients in either group wore an ileostomy bag. We concluded that recent technical changes have improved the results after continent ileostomy.

Adult↗
PubMed1980

Campylobacter fetus ss. jejuni: a cause of massive lower gastrointestinal hemorrhage.

A patient is described with Campylobacter enteritis complicated by massive lower gastrointestinal bleeding from multiple mucosal ulcers in the terminal ileum and at the ileocecal valve. Repeated stool cultures and antibiotic therapy may be indicated in certain patients to diminish the morbidity arising from what may seem to be mild disease. In patients who suffer bleeding complications, arteriography before surgery is necessary to demonstrate an otherwise grossly indefinable source of bleeding.

Adult↗
PubMed1980

Proximal gastric vagotomy. Initial experience.

Proximal gastric vagotomy was performed in 223 patients with chronic duodenal ulceration between 1973 and 1977. The follow-up ranged from 6 to 78 months with a mean of 39 months. There was no operative mortality. Adverse postoperative sequelae, including delayed gastric emptying, dumping, diarrhea, and reflux gastritis, were seen in less than 3% of patients. Ulcers recurred in 11 patients (4.9%). We conclude that proximal gastric vagotomy is an effective, safe, and satisfactory operation for chronic duodenal ulcer over the short term.

Chronic Disease↗
PubMed1980

Reflux of duodenal contents into the pancreatic duct of dogs.

Previously we demonstrated that postprandial duodenal pressure transiently exceeds pancreatic duct pressure in the dog. To determine whether this presure gradient causes reflux from the duodenum into the pancreatic duct, we provided each of five dogs with a permanent pancreatodochal catheter and three indwelling duodenal cutaneous catheters. 14C-PEG was infused through the proximal duodenal catheter; intraluminal pressures were monitored through the middle catheter at the level of the pancreatic duct orifice; and 15 cm abroad, duodenal contents were recovered from the third catheter. Fifteen-minute pooled samples were collected 1 hr preprandially and 2 hr postprandially from the pancreatic duct and duodenum and were analyzed for volume, lipase activity, and marker concentration. Reflux of duodenal contents occurred only in 10.8% of fasting periods but was observed in 38% of postprandial periods (p < 0.05). The total volume of duodenal content refluxed per 15 min approximated 0.1 ml and represented between 0.5% and 1% of total pancreatic volume flow and between 0.05% and 0.07% of total duodenal volume flow. Thus we have provided evidence that small amounts of duodenal contents may reflux into the pancreatic duct of dogs in our experimental model. This finding may be relevant to the pathogenesis of pancreatitis and pancreatic cancer.

Animals↗