Obturator hernia: current diagnosis and treatment.

BACKGROUND: Obturator hernia is a rare pelvic hernia for which both diagnosis and therapy are difficult. Because symptoms are nonspecific and specific physical findings are often obscure, diagnosis of obturator hernia is often delayed until laparotomy for bowel obstruction. Strangulation is frequent, and mortality remains high (25%). Primary closure of the hernia defect is difficult because adjacent tissues are not easily mobilized. Although a variety of techniques have been described, surgical repair has not been standardized. METHODS: We report a case of bilateral obturator hernia with incarceration in association with bilateral femoral hernia in which these problems were satisfactorily addressed. RESULTS: The hernias were diagnosed by computed tomography (CT) scan and repaired with synthetic mesh placed in the preperioneal space. This technique is well suited to unilateral and bilateral combinations of obturator, inguinal, and femoral hernias. CT scan in the work-up of severe gastrointestinal symptoms with weight loss may lead to a diagnosis of occult hernia, thereby allowing elective repair and, hopefully, a reduction in mortality risk. CONCLUSIONS: We recommend CT scan for suspected obturator hernia and preperitoneal mesh repair of noninfected cases.

Treatment of intra-abdominal infections is appropriate with single-agent or combination antibiotic therapy.

In a prospective, randomized, single-blind trial, we studied 112 adults with intra-abdominal infections and compared antibiotic therapy with cefoxitin plus placebo to therapy with tobramycin plus clindamycin. Seventy-five percent of patients receiving tobramycin-clindamycin and 71% of those receiving cefoxitin-placebo had either shock, bacteremia, malnutrition, alcoholism, rapidly or ultimately fatal underlying disease, infection originating from the distal small bowel or colon, or had had failed therapy before treatment ("high-risk" group). One third of the patients in both groups grew bacteria in the initial culture resistant to the antibiotic regimen used. Ten patients receiving cefoxitin-placebo (17%) and 11 receiving tobramycin-clindamycin (21%) had recurrence of infection or died of infection (clinical failures). Nineteen failures occurred in high-risk patients (p less than 0.05) and 17 were in patients that had antibiotic-resistant bacteria in the initial culture (p less than 0.01). Adverse effects were rare and remitted after antibiotics were stopped. Our results suggest that both cefoxitin and tobramycin-clindamycin are appropriate antibiotic regimens to treat intra-abdominal infections. Clinical failure is more common in high-risk patients and when antibiotic-resistant organisms are isolated from initial cultures.

The risk of infection after colon injury.

We reviewed 137 patients with colon injury and applied multiple regression analysis to determine the influence of various parameters on colon-related infection. The complications of intra-abdominal abscess, wound infection, and peristomal abscess occurred in 25% of patients. The mortality rate was 3.6%, and four of five late deaths were caused by infection. Multiple regression analysis identified the amount of blood transfused, patient age, number of associated injuries, and injury to the spleen as significantly associated with infection (p less than 0.05). In the absence of these risk factors, the likelihood of infection is low, suggesting that primary repair or resection and anastomosis are safe methods of management for colon injury. When these factors are present, the risk of infection is high, and colostomy is the preferred method of management.

Urinary adenosine excretion in patients receiving amphotericin B.

BACKGROUND: Intravenous amphotericin B (AMB) administration in animals causes renal vasoconstriction, ischemia, and oliguria that may result in irreversible renal injury; the mechanism of AMB nephrotoxicity may be similar in human beings. Adenosine is excreted in urine by the ischemic kidney. We hypothesized that adenosine excretion and oliguria would be a marker for patients who later would manifest AMB-associated renal insufficiency and that pre-AMB saline administration (which ameliorates AMB nephrotoxicity) would negate the change in adenosine excretion and urine output. METHODS: Twenty hospitalized patients being treated at the direction of their attending physician and who were receiving AMB (15 to 75 mg intravenously) had urine collected for 1 hour before and for 2 hours during AMB infusion. Eleven patients received normal saline solution (500 ml intravenously) before the AMB infusion; the other nine formed the comparator group. An aliquot of each urine collection was precipitated with perchloric acid to remove protein and cellular elements and centrifuged, and the supernatant was assayed for adenosine by using high-pressure liquid chromatography. RESULTS: Infusion of AMB was associated with a decrease in mean urine output both in patients who received saline solution (245 before versus 149 ml/hr during AMB infusion, p = 0.04) and in patients in comparator group (139 versus 89 ml/hr, p = 0.027). The mean urinary adenosine excretion was unchanged in the saline-loaded group (0.1354 before versus 0.1255 mmol/hr during drug infusion, p = 0.25) and was decreased in the comparator group (0.2276 versus 0.1127 mmol/hr, p = 0.01). Development of renal insufficiency did not correlate with the change in urine output or adenosine excretion. CONCLUSIONS: AMB infusion in human beings results in decreased urine output and decreased adenosine excretion. The latter effect is prevented by a pre-AMB saline load. The changes in urine output and adenosine excretion are not predictive of the development of renal insufficiency.

Hypothesis: compartmentalization of cytokines in intraabdominal infection.

BACKGROUND: Although the proximal role of systemic cytokines in the infectious-inflammatory cascades is well recognized, the magnitude and meaning of its intraperitoneal levels in peritonitis have received little attention. We hypothesized that in peritonitis a significant and clinically relevant cytokine-mediated inflammatory response is compartmentalized in the peritoneal cavity. METHODS: MEDLINE was used to search the literature for all articles dealing with experimental, primary, and secondary bacterial peritonitis and cytokines. RESULTS: Bacterial peritonitis is associated with an immense intraperitoneally compartmentalized cytokine response, with plasma levels of cytokines representing only the tip of the iceberg. Although certain amount of cytokines may be beneficial to the peritoneal defense mechanisms, higher levels correlate with adverse outcome. Thus it is plausible to look at acute peritonitis as initially a combined infective (microorganism) and inflammatory (cytokines) process. The clinical significance of the distinction between peritoneal inflammation and infection and the relevance of our findings to the stratification and treatment of peritonitis are discussed. CONCLUSIONS: Current surgical and antibiotic therapy for peritonitis is able to clear the peritoneal cavity of infective concentration of bacteria, but many patients continue to die of an uncontrolled activation of the inflammatory cascade. We suggest that one potential venue for therapeutic progress is the modulation of the compartmentalized peritoneal inflammatory response.

Prospective trial of proximal gastric vagotomy.

Forty men who were to have elective operation for nonobstructive duodenal or pyloric channel ulcer were randomized prospectively to undergo either proximal gastric vagotomy without drainage (PGV, n = 18) or selective vagotomy, antrectomy, and gastroduodenostomy (SVA, n = 22). Gastric acid analyses were accomplished before and 3 and 12 months after operation. Clinical interviews were conducted yearly. Thirty-nine patients were evaluable at 2 years, 25 at 4 years, and 15 at 5 years. No operative deaths occurred. Recovery was more rapid and the incidence of serious operative morbidity was lower after PGV than after SVA. Reduction of basal and stimulated gastric secretion was greater after SVA than PGV. Significant long-term sequelae other than recurrent ulcer were less frequent after PGV compared to SVA. Recurrent ulcer may occur more often after PGV; 3-month gastric secretory studies may be helpful in anticipating recurrence. Patients who undergo PGV have a particularly increased risk of developing pyloric channel ulcer disease, and low secretory values indicating an adequate vagotomy do not assure future protection from pyloric channel ulcer recurrence. Long-term sequelae after SVA, particularly dumping, do not have dependable reoperative options, whereas antrectomy should be a reliable reoperative solution to ulcer recurrence after PGV. PGV, performed correctly with a 5 to 7 cm vagal-esophageal separation, is preferable to vagotomy and resection for elective treatment of nonobstructing duodenal ulcer disease.

Intestinal motility changes in experimental large bowel obstruction.

Bipolar electrodes for recording electrical discharges of colon smooth muscle and strain gages for recording associated contractions of circular muscle were implanted in six rhesus monkeys. After recovery, baseline records were made. The animals then had an obstruction device implanted in sigmoid colon which resulted in progressive compromise of the lumen terminating in complete obstruction after 13 +/- 2 days. Recording were made daily during development of obstruction. As obstruction became more complete, contraction frequency decreased in right colon, increased in left colon proximal to the obstruction, and was unchanged in left colon distal to the obstruction. The frequency of distentions increased in colon proximal to the obstruction but was unchanged distally. Simultaneous mass actions, a complex of nonperistaltic high amplitude contractions and distentions occurring nearly simultaneously throughout the colon which is not seen in normal colon, appeared in colon both proximal and distal to the obstruction and became more frequent as the degree of obstruction progressed. Colon obstruction results in abnormal motility complexes, but not in hyperperistalsis. Mass actions probably are the basis for colic and rushing bowel sounds noted clinically in colon obstruction.

Effects of halothane, enflurane, and nitrous oxide on colon motility.

Previous work from this laboratory has demonstrated that the colon, particularly the left colon, is the major site of persistent postoperative ileus after both minimal and more extensive abdominal operations. Inhalation anesthetics have been implicated in the past as a possible cause of altered postoperative bowel function, but direct evidence of such a role in postoperative ileus is lacking. In this investigation, the effects of three inhalation anesthetic agents, halothane, enflurane, and nitrous oxide, on contractile function of the right and left colon were investigated in monkeys. Enflurane and halothane administration caused cessation of contractions in both the left and right colon; suppression of motor activity continued throughout the period of anesthetic administration. Recovery of normal contractile function occurred relatively promptly after cessation of anesthesia with these drugs. Return of normal contractions was more prompt in the right than in the left colon. Administration of nitrous oxide was not associated with significant suppression of contractile function of either the the right or left colon. None of the three agents studied appear to have any role in typical postoperative ileus.

Influence of sleep deprivation on learning among surgical house staff and medical students.

BACKGROUND: Sleep deprivation as a result of in-house night call may alter capacity to learn. Surgical residents and medical students, in both sleep-deprived and rested states, read surgical journal articles and later answered questions regarding their content as a measure of ability to learn while participating in scheduled night call. METHODS: Medical students (n = 35) and residents (n = 21) rotating on surgical services kept logs of hours slept during a 4-week study period. Subjects read six selected articles at separate early morning sittings during weeks 1 and 3. A multiple choice test was given 1 week after each session to assess short-term recall, and all tests were given again 3 months later to assess retention of information over the longer term. Scores were compared with the sleep data. Subjective measures of fatigue and motivation elicited from subjects also were evaluated. RESULTS: Sleep deprivation (4 hours or less uninterrupted sleep per night) resulted in increased fatigue and decreased motivation among medical students and residents (p < 0.05, t test). Objective scores on tests administered 1 week and 3 months after reading did not show an effect attributable to sleep deprivation (p > 0.05, t test). CONCLUSIONS: Sleep deprivation leads to subjective feelings of increased fatigue and decreased motivation. Residents and medical students, however, whether sleep deprived or not, obtain comparable scores on objective tests measuring both short-term and long-term retention of newly learned material. The ability to learn medically relevant information does not appear to be significantly altered by the degree of sleep deprivation associated with clinical rotations on surgical services.

Effects of adrenergic agents on colonic motility.

Sympathetic hyperactivity has been implicated as an etiologic factor in postoperative ileus. The effects of methoxamine (alpha-agonist) and isoproterenol (beta-agonist) on colon contractions and blood flow were studied in nine monkeys. Phentolamine (alpha-antagonist) and propranolol (beta-antagonist) were used to block the effects of the appropriate agonist. Methoxamine caused a dose-related inhibition of colon contractions and a decrease in inferior mesenteric artery (IMA) blood flow. Isoproterenol caused a dose-related inhibition of colon contractions and an increase in IMA blood flow. The contractile and blood flow effects of methoxamine were blocked by phentolamine and those of isoproterenol by propranolol. Mechanical reduction of IMA blood flow by an amount equivalent to that observed with the highest dose of methoxamine caused no change in contractions in the segment of colon supplied by the IMA. Both alpha- and beta-agonists inhibit colon contractions and have the expected effects on IMA blood flow. The contractile and blood flow responses of the agonists can be blocked by appropriate antagonists. The blood flow changes are not responsible for the contractile changes. These results indicate that sympathetic hyperactivity may play a role in postoperative ileus.

The effect of whole-gut lavage on colon motility and gastrocolic response in a monkey.

The effects of thorough colon lavage on fasting electrical control and response activities, as well as on muscular contractions, were recorded from the right, transverse, mid, and left colon of four conditioned monkeys. The gastrocolic response of monkeys to feeding is most prominent in the right and transverse colon in both duration and frequency of contractions. The response is reduced in midcolon and is just discernible in the left colon in fasted but otherwise unprepared animals. After lavage of the colon, a gastrocolic response to feeding is vigorously present throughout the colon. The removal of colonic content by lavage also leads to an increase in the duration of the gastrocolic response. These experimental observations are consistent with the results noted in humans in similar although less systematic experiments. Although the mechanism is unknown, the presence of stool in the lumen appears to blunt the contractile gastrocolic response of the colon to feeding.

Surgical sepsis: constancy of antibiotic susceptibility of causative organisms.

BACKGROUND: It is well documented that antibiotic therapy exerts selective pressure on bacteria. Conversion of bacteria from susceptible to resistant to antibiotics has been observed often during antimicrobial therapy. It has been postulated that human intestinal reservoirs facilitate communication of transposons that can transfer resistance determinants among various bacterial species. METHODS: This study examined the susceptibilities of organisms isolated from infected abdomens to a number of antibiotic agents during a 12-year time interval. Analysis included 1102 isolates recovered from 255 specimens, representing the following genera: Bacteroides, Clostridium, Gemella, Fusobacterium, Peptostreptococcus, Porphyromonas, Prevotella, Enterococcus, Staphylococcus, Streptococcus, Pseudomonas, and Enterobacteriaceae. Strains were tested against beta-lactam agents, beta-lactams in combination with beta-lactamase inhibitors, first, second, and third generation cephalosporins, aminoglycosides, clindamycin, metronidazole, chloramphenicol, and imipenem. RESULTS: The results indicated that during a time period of more than a decade essentially no change occurred in the antibiotic susceptible fraction of all species tested. CONCLUSIONS: Abdominal sepsis is caused by leakage of endogenous intestinal flora. This study suggests that the intestinal flora is not permanently affected by short-term antibiotic therapy and that older antibiotics are appropriate first-line therapeutic agents for community-acquired infections caused by normal intestinal flora.

Postoperative ileus: a colonic problem?

Postoperative electromechanical activity of the gastric antrum, small bowel, right colon, and sigmoid colon was recorded in stumptail monkeys in response to retroperitoneal dissection and transient clamping of the renal pedicle. Bipolar silver electrodes and extraluminal bonded strain gauge transducers were used to record slow-wave and spike discharges and contractions of intestinal smooth muscle. After operation myoelectric activity was decreased transiently in the antrum and for only a few hours in the small bowel. Right colon contractile activity was decreased significantly for 24 hours and that of the sigmoid colon for 72 hours. Postoperative inhibition of bowel motility appears to be most profound and persistent in the colon.

Effect of ascorbic acid on rectal polyps of patients with familial polyposis.

Evidence for dehydrogenation by fecal bacteria in the genesis of colon cancer suggested that an antioxidant might modify these mechanisms. Ascorbic acid, 3 Gm. daily, was given to five patients who had active rectal adenomatous polyp formation long after ileorectal anastomosis for familial polyposis. During a 4 to 13 month study, rectal polyps disappeared in two, regressed partially in two, and increased in one. Among three additional treated patients with rectal polyps, one had a reduction in polyps and two were unaffected.

Proximal gastric vagotomy versus selective vagotomy with antrectomy: results of a prospective, randomized clinical trial after four to twelve years.

This prospective, randomized study of selective vagotomy with antrectomy (SVA) versus proximal gastric vagotomy (PGV) for patients with duodenal ulcer compares the incidence of recurrent duodenal ulcer and postoperative morbidity during a 4- to 12-year follow-up period. In 46 patients with SVA there were no recurrent ulcers, but 26% of these individuals had serious digestive problems that were not amenable to medical treatment. The 40 patients with PGV had eight recurrent ulcers (20%), but five of these were found in the first 15 patients (33%) compared with three in the 25 patients (12%) who had operations after the need for extensive periesophageal denervation was discovered in the mid-1970s. Most recurrent ulcers were amenable to medical treatment, but 5% of the patients who had PGV had postoperative dysphagia that required periodic bougienage. The data are consistent with several interpretations, depending on the bias of the individual. However, based upon the fact that recurrent ulcers could be managed nonoperatively after PGV versus the lack of effective treatments for postgastrectomy complaints after SVA, it is reasonable to consider wider use of PGV. There are reasons to believe that the variable ulcer recurrence rates after PGV can be explained by subtle differences in operative technique, including those based upon use of the Congo red test for completeness of vagotomy. Unlike SVA, PGV remains an operative procedure in evolution that requires further clinical investigation. At this time either operation can be applied if both the surgeon and the patient have a clear understanding of the possible effects.

A comparison of prosthetic materials used to repair abdominal wall defects.

A large abdominal wall hernia, not amenable to primary closure, may require insertion of a prosthesis. The ideal prosthesis maintains strength, is incorporated by surrounding tissues, and does not stimulate adhesions. These qualities vary among available synthetic prostheses. We tested tensile strength, bursting strength, and adhesion formation in response to six materials used in repair of abdominal wall hernias. Adult Sprague-Dawley rats (196) were randomly divided into a control group and six experimental groups. A 4 by 4 cm full-thickness resection of abdominal wall was closed with patches of polypropylene mesh (Marlex), polyglactin 910 mesh (Vicryl), expanded polytetrafluoroethylene (Gore-tex), Dacron-reinforced silicone rubber (Silastic), preserved human dura (PHD), or polypropylene mesh overlying gelatin film (Marlex and Gelfilm, respectively). In controls the 4 cm longitudinal full-thickness incisions were closed primarily. Seven rats randomly selected from each group were sacrificed after 1, 2, 4, and 8 weeks; bursting and tensile strength (tensiometer) and adhesion formation were assessed. There were no differences in bursting strength among the experimental groups at each testing period. Although bursting strength increased linearly with time it was significantly weaker than in controls at 1 and 8 weeks (P less than 0.05). Tensiometric data were inconclusive due to wide variability within the experimental groups. Adhesion formation was moderate to maximal at all evaluation periods for Marlex and Gore-tex. Early adhesion formation was minimal to moderate for both PHD and Vicryl, but later increased with PHD and decreased with Vicryl as this prosthesis was absorbed. No adhesions formed with Marlex and Gelfilm until the gelatin dissolved (1 week), after which the adhesion response was similar to that with Marlex alone. No adhesions formed after Silastic implantation, but graft extrusion and evisceration were common (75%). Controls had no adhesions at all evaluation periods. Wound strength was similar for all prosthetic materials. Absorbable prosthetic Vicryl provided the best long-term protection against adhesions.

Inguinal hernia repair before and after prostatic resection.

From 1976 through 1981, 864 men had inguinal hernia repairs and 328 had prostatic resections at our Veterans Administration Hospital. Forty-four patients had symptomatic prostatic obstruction that required either transurethral or open prostatic resection within 12 months of hernia repair. Twenty-seven patients had prostatectomy prior to hernia repair, 16 had hernia repair before prostatic resection, and one had simultaneous procedures. There were no urinary tract infections (UTIs) after hernia repair in patients who had had prostatectomy first, while five patients who had hernia repair before prostatectomy developed UTI after hernia repair (P less than 0.01). The incidence of UTI after hernia repair correlated with the need for and duration of bladder catheterization as a result of prostatic obstruction. Complications after prostatectomy were similar regardless of the order of operation. There were no episodes of incarceration or strangulation in patients awaiting hernia repair after prostatectomy. These results suggest that, when an inguinal hernia and symptomatic prostatic obstruction occur together, the performance of prostectomy before hernia repair lowers the risk of morbidity by decreasing the incidence of UTI after hernia repair. This approach does not expose the patient to any additional risk related to the inguinal hernia.

Relationship of duration of postoperative ileus to extent and site of operative dissection.

Postoperative ileus has been thought to be related to intraoperative manipulation of the intestines and to the duration of operative procedures. In order to study the effect of these variables on the postoperative myoelectrical activity of the intestine, six stumptailed monkeys had strain-gauge force transducers and bipolar electrodes placed on gastric antrum, mid-small bowel, right colon, and sigmoid colon. The animals were then subjected to three operations in random order varying in extent and site of dissection: (1) midline incisions, mobilization of right colon and kidney, clamping of renal pedicle, and extensive blunt dissection of right retroperitoneum; (2) the same operation but done on the left side; and (3) midline incision and gentle digital manipulation of the intestines. The first two procedures involved much more intestinal handling and dissection and took five to six times longer than the minimal laparotomy procedure. Postoperative inhibition of bowel motility was most profound and persistent in the colon. The duration and pattern of postoperative ileus in these experiments were independent of the extent, site, and duration of the operative procedure.

Factors influencing the risk of early and late serious infection in adults after splenectomy for trauma.

We reviewed the clinical course of 245 adults who underwent splenectomy for trauma to assess the risk of both early and late serious infection. Twenty-one patients (9%) had an early serious infection (sepsis) during hospitalization for splenectomy. The mortality rate was 62% in patients with early sepsis, and encapsulated bacteria were isolated from the blood of 43% of patients with sepsis. Only one of 58 patients with isolated splenic injury had sepsis (2%), and the risk of early sepsis increased when three or more concomitant injuries were present (p less than 0.05). Stepwise multiple regression analysis revealed that patients with injuries to the pancreas, colon, or central nervous system or with extremity fractures had an increased risk of sepsis (p less than 0.05). The risk of sepsis was not influenced by age, the type of injury, delay in operation, use of drains, or other individual injuries. Sufficient information was available to assess the risk of late serious infection for 140 surviving patients (63%). Follow-up ranged from 2 to 277 months. Three late infections occurred at 2, 8, and 15 years after splenectomy; two were due to Streptococcus pneumoniae. None of these patients died. There were no identifiable factors influencing the risk of late infection. These results suggest that the risk of early serious infection in adults after splenectomy for trauma is low when isolated splenic injury is present but that this risk is increased by both the degree of injury and the presence of certain associated injuries. Encapsulated bacteria are frequent pathogens in both early and late infections. The mortality rate related to an early septic episode is high, but the risk of late serious infection is low and is not related to identifiable factors that decrease host defenses.

Effects of vagal cryo-interruption on colon contractions in monkeys.

The influence of the vagus nerve on normal colon contractions, and the distal extent of this influence along the colon, is unknown. It is generally thought that the vagus nerve has little, if any, influence on normal colon contractions, and if there is any effect, it is limited to the proximal colon. The technique of reversible truncal vagotomy by cooling (vagal cryo-interruption) was used to explore the influence, and extent of any influence, of the vagus nerve on contractions of the colon in unanesthetized monkeys. Each monkey was subjected to vagal cryo-interruption in the fasted and fed states. In both states this caused a significant decrease in contractions in the proximal, middle, and distal portions of the colon, compared with baseline control and recovery periods. These studies indicate that the vagus nerve plays a role in normal contractions of the intra-abdominal colon in both the fasted and the fed states and that it also plays a role in the gastrocolic response.