Laparoscopic mesh hiatoplasty for paraesophageal hernias and fundoplications: a critical analysis of the available literature

BACKGROUND

Little grade A medical evidence exists to support the use of prosthetic material for hiatal closure. Therefore, the authors compiled and analyzed all the available literature to determine whether the use of prosthetic mesh in hiatoplasty for routine laparoscopic fundoplications (LF) or for the repair of large (>5 cm) paraesophageal hernias (PEH) would decrease recurrence.

METHODS

A literature search was performed using an inclusive list of relevant search terms via Medline/PubMed to identify papers (n = 19) describing the use of prosthetic material to repair the crura of patients undergoing laparoscopic PEH reduction, LF, or both.

RESULTS

Case series (n = 5), retrospective reviews (n = 6), and prospective randomized (n = 4) and nonrandomized (n = 4) trials were identified. Laparoscopic procedures (n = 1,368) were performed for PEH, gastroesophageal reflux disease (GERD), hiatal hernia, or a combination of the three. Group A (n = 729) had primary suture repair of the crura, and group B (n = 639) had repair with either interposition of mesh to close the hiatus or onlay of prosthetic material after hiatal or crural closure. The use of mesh was associated with fewer recurrences than primary suture repair in both the LF and PEH groups. The mean follow-up period did not differ between the groups (20.7 months for group A vs. 19.2 months for group B). None of the papers cited any instance of prosthetic erosion into the gastrointestinal tract.

CONCLUSIONS

The current data tend to support the use of prosthetic materials for hiatal repair in both routine LF and the repair of large PEHs. Longer and more stringent follow-up evaluation is necessary to delineate better the safety profile of mesh hiatoplasty. Future randomized trials are needed to confirm that mesh repair is superior to simple crural closure.

Postoperative complications are not increased in super-super obese patients who undergo laparoscopic Roux-en-Y gastric bypass

BACKGROUND

It has been suggested that super-super obesity (body mass index [BMI] > or =60 kg/m2) increases the risk of complications after laparoscopic Roux-en-Y gastric bypass (LapRYGB). We hypothesized that a higher BMI does not increase risk the morbidity or mortality rate.

METHODS

Complication rates for patients with a BMI > or =60 kg/m2 were compared to those for patients with a BMI <60 kg/m2 who underwent LapRYGB during the same time period. Differences between the groups were analyzed by Fisher's exact test, t-tests, and analysis of variance.

RESULTS

Forty-five patients with a BMI > or =60 kg/m2 and 640 patients with a BMI <60 kg/m2 underwent LapRYGB. There were no statistically significant differences between the two groups in the complication or mortality rates. Excess weight loss was less, but actual weight lost was greater in the BMI > or =60 kg/m2 group.

CONCLUSIONS

The complication and mortality rates are not increased in super-super obese patients who undergo LapRYGB. Acceptable weight loss can be achieved safely in these patients.

Optimal management of the morbidly obese patient SAGES appropriateness conference statement

BACKGROUND

Obesity is a growing health problem that contributes to numerous life-threatening or disabling disorders, including coronary artery disease, hypertension, type 2 diabetes mellitus, hyperlipidemia, degenerative joint disease, and obstructive sleep apnea. Significant weight reduction in the morbidly obese improves or reverses associated illness and benefits well-being. The purpose of the SAGES Appropriateness Conference was to summarize the state of the art for open and laparoscopic operations for the morbidly obese.

METHODS

The English literature comparing bariatric procedures was reviewed and grouped by level of evidence by three surgeons (BS, LV, and CC). From more than 1,500 articles, all conference participants were provided with reprints and table summaries of no less than 50 selected manuscripts. Ten experts were requested to present reviews and make evidence-based arguments for and against the open and laparoscopic approaches in written format. An expert panel of six surgeons, including an ethicist and patient, commented on implications of data presented. The finalized statement was e-mailed to all participants for approval and comment.

RESULTS

Consensus statements were achieved on various aspects of morbid obesity, including indications for surgery, resolution of comorbid illnesses with significant weight loss, and the importance of committed bariatric program. Our panel of experts agreed, in general, to the advantages of laparoscopic approaches compared to open operations in skilled hands.

CONCLUSIONS

Laparoscopic Roux-en-Y gastric bypass (RYGB) affords improved short-term recovery compared to open gastric bypass. Laparoscopic adjustable banding can be performed with lower average mortality than either RYGB or any of the malabsorptive operations, and it produces variable degrees of short-term weight loss. Prospective randomized trials are needed to compare gastric bypass, malabsorptive, and restrictive procedures.

Experience with over 3,000 open and laparoscopic bariatric procedures: multivariate analysis of factors related to leak and resultant mortality

BACKGROUND

Intestinal leak is a potentially lethal complication of Roux en-Y gastric bypass (GBP). Identification of patients at high risk for leak may reduce complication rates of surgeons early in the procedure learning curve.

METHODS

A total of 3073 patients who underwent GBP were analyzed using univariate and multivariate logistic regression analyses of the following preoperative factors: hypertension (HTN), diabetes mellitus (DM), sleep apnea (SA), age, gender, weight, body mass index (BMI), and surgery type. Multivariate logistic regression analysis was performed for each procedure type.

RESULTS

There were 48 (1.5%) deaths. Independent risk factors for death included leak, weight, procedure type, and HTN. A total of 102 (3.2%) leaks were found. Independent factors for leak included age, male gender, SA, and procedure type.

CONCLUSION

The data suggests that older, heavier male patients with multiple comorbid conditions are at increased risk for leak and mortality. Surgeons early in their learning curve should avoid these high-risk patients to reduce complications.

Training the novice in laparoscopy. More challenge is better

BACKGROUND

Virtual reality simulation is effective in training the novice to perform basic laparoscopic skills.

METHODS

Using the Minimally Invasive Surgery Training--Virtual Reality (MIST-VR) trainer, 27 honors high school students were tested at the easy level, prospectively randomized to eight training sessions at the easy (group A, n = 14) or medium (group B, n = 13) level, then retested at the easy level.

RESULTS

Both groups were statistically similar at baseline. All scores improved significantly (50.1% to 81.3%) over the period of training (p < 0.05). Although the group A scores were significantly better than the group B scores throughout training (p < 0.05), on final testing at the easy level, group B surpassed group A for all the tasks except TransferPlace (p = 0.054).

CONCLUSIONS

Virtual simulation is an effective laparoscopic training method for the novice, providing significant improvement in skill levels over a relatively short period. More challenging training seems to predict greater improvement over time and better final skill levels.

Hand-assisted laparoscopic gastric bypass does not improve outcome and increases costs when compared to open gastric bypass for the surgical treatment of obesity

BACKGROUND

Hand-assisted laparoscopic Roux-en-Y gastric bypass (Hand-Lap GB) has been adopted by some surgeons to treat morbid obesity because it is easier to perform than the total laparoscopic procedure, but to date no study has compared the outcomes of patients undergoing the Hand-Lap GB to those obtained with the open procedure (Open GB). We hypothesized that patients undergoing Hand-Lap GB would lose a similar amount of weight when compared to Open GB patients, while experiencing no increase in complications, a shorter hospital stay, and lower overall costs of care, in part as a result of fewer incisional hernias requiring subsequent surgery.

METHODS

Nonrandomized, prospective data were collected on all patients undergoing proximal GB via Hand-Lap or open approaches between May 1998 and July 1999. Our first 25 Hand-Lap GB procedures, performed in selected patients (with no extensive previous abdominal surgery) referred to two of us (E.J.D, M.A.S), were compared to all other (n = 62) concurrent open proximal GB performed by the group during this period of time in patients with body mass index (BMI) <50 kg/m2.

RESULTS

Preoperatively, Hand-Lap GB patients did not differ from Open GB patients in age (40 +/- 11 vs 43 +/- 11 years), gender (92% female vs 81% female), incidence or type of preoperative comorbid conditions, preoperative weight (282 +/- 33 vs 280 +/- 37 lb), or BMI (45.5 +/- 5.4 vs 44.1 +/- 3.3 kg/m2). (Data given as mean +/- standard deviation). Although length of hospital stay did not differ between groups (3.6 +/- 1.3 vs 4.2 +/- 4.6 days), total hospital costs were significantly higher for Hand-Lap GB ($14,725 +/- 3089 vs. $10,281 +/- 3687, p <0.01 ANOVA). One patient in the Open GB group developed an anastomotic leak from the gastrojejunostomy. Follow-up revealed that Hand-Lap GB patients had a similar risk of postoperative complications as the Open GB group, including marginal ulcer (16% vs 14.5%), stomal stenosis (24% vs 23%), and, most notably, incisional hernia (20% vs 27%). There were no major wound infections or deaths in either group. One patient in each group developed a postoperative small bowel obstruction. Loss of excess weight in Hand-Lap GB patients at 12 months postoperatively was 66 +/- 14% vs 77 +/- 14% in the Open GB group.

CONCLUSIONS

The Hand-Lap GB yielded good weight reduction in a population of morbidly obese patients, but at a higher cost for hospital care than Open GB. There was no decrease in the incidence of incisional hernias with the Hand-Lap GB procedure. Although Hand-Lap GB appears to be safe and effective, its failure to provide a decrease in hospital stay or risk of incisional hernia requiring subsequent surgical repair is significant. The primary role for the Hand-Lap GB procedure should therefore be to aid surgeons in developing skills to climb the steep learning curve for total laparoscopic gastric bypass, since Hand-Lap GB does not improve patient outcome and increases cost in comparison to the open GB procedure.

Laparoscopic adjustable silicone gastric banding

Laparoscopic adjustable silicone gastric banding (LASGB) is a relatively new surgical procedure for the treatment of morbid obesity The most popular banding procedure is the vertical banded gastroplasty, however, there are risks involved in this procedure, including staple-line disruption and postoperative intractable vomiting. This article presents the advantages of using the LASGB device over former types of gastric banding.

Risks and benefits of gastric bypass in morbidly obese patients with severe venous stasis disease

OBJECTIVE

To determine the risks and benefits of gastric bypass-induced weight loss on severe venous stasis disease in morbid obesity.

SUMMARY BACKGROUND DATA

Severe obesity is associated with a risk of lower extremity venous stasis disease, pretibial ulceration, cellulitis, and bronze edema.

METHODS

The GBP database was queried for venous stasis disease including pretibial venous stasis ulcers, bronze edema, and cellulitis.

RESULTS

Of 1,976 patients undergoing GBP, 64 (45% female) met the criteria. Mean age was 44 +/- 10 years. Thirty-seven patients had pretibial venous stasis ulcers, 4 had bronze edema, 23 had both, and 17 had recurrent cellulitis. All had 2 to 4+ pitting pretibial edema. Mean preoperative body mass index (BMI) was 61 +/- 12 kg/m(2) and weight was 179 +/- 39 kg (270 +/- 51% ideal body weight), significantly greater than in patients who underwent GBP without venous stasis disease. Two patients had a pulmonary embolus and four had Greenfield filters in the remote past. Additional comorbidities included obesity hypoventilation syndrome, sleep apnea syndrome, hypertension, gastroesophageal reflux, degenerative joint disease symptoms, type 2 diabetes mellitus, pseudotumor cerebri, and urinary incontinence. Comorbidities were significantly more frequent in the patients with venous stasis disease than for those without. At 3.9 +/- 4 years after surgery, patients lost 55 +/- 21 % of excess weight, 62 +/- 33 kg, reaching 40 +/- 9 kg/m(2) BMI or 176 +/- 41% ideal body weight. Venous stasis ulcers resolved in all but three patients. Complications included anastomotic leaks with peritonitis and death, fatal pulmonary embolism, fatal respiratory arrest, wound infections or seromas, staple line disruptions, marginal ulcerations treated with acid suppression, stomal stenoses treated with endoscopic dilatation, late small bowel obstructions, and incisional hernias. There were six other late deaths.

CONCLUSIONS

Severe venous stasis disease was associated with a significantly greater weight, BMI, male sex, age, comorbidity, and surgical risk (pulmonary embolus, leak, death, incisional hernia) than in other patients who underwent GBP. Surgically induced weight loss corrected the venous stasis disease in almost all patients as well as their other obesity-related problems.

High failure rate after laparoscopic adjustable silicone gastric banding for treatment of morbid obesity

OBJECTIVE

To report the results from one of the eight original U.S. centers performing laparoscopic adjustable silicone gastric banding (LASGB), a new minimally invasive surgical technique for treatment of morbid obesity.

SUMMARY BACKGROUND DATA

Laparoscopic adjustable silicone gastric banding is under evaluation by the Food & Drug Administration in the United States in an initial cohort of 300 patients.

METHODS

Of 37 patients undergoing laparoscopic placement of the LASGB device, successful placement occurred in 36 from March 1996 to May 1998. Patients have been followed up for up to 4 years.

RESULTS

Five patients (14%) have been lost to follow-up for more than 2 years but at last available follow-up (3-18 months after surgery) had achieved only 18% (range 5-38%) excess weight loss. African American patients had poor weight loss after LASGB compared with whites. The LASGB devices were removed in 15 (41%) patients 10 days to 42 months after surgery. Four patients underwent simple removal; 11 were converted to gastric bypass. The most common reason for removal was inadequate weight loss in the presence of a functioning band. The primary reasons for removal in others were infection, leakage from the inflatable silicone ring causing inadequate weight loss, or band slippage. The patients with band slippage had concomitant poor weight loss. Bands were removed in two others as a result of symptoms related to esophageal dilatation. In 18 of 25 patients (71%) who underwent preoperative and long-term postoperative contrast evaluation, a significantly increased esophageal diameter developed; of these, 13 (72%) had prominent dysphagia, vomiting, or reflux symptoms. Of the remaining 21 patients with bands, 8 currently desire removal and conversion to gastric bypass for inadequate weight loss. Six of the remaining patients have persistent morbid obesity at least 2 years after surgery but refuse to undergo further surgery or claim to be satisfied with the results. Overall, only four patients achieved a body-mass index of less than 35 and/or at least a 50% reduction in excess weight. Thus, the overall need for band removal and conversion to GBP in this series will ultimately exceed 50%.

CONCLUSIONS

The authors did not find LASGB to be an effective procedure for the surgical treatment of morbid obesity. Complications after LASGB include esophageal dilatation, band leakage, infection, erosion, and slippage. Inadequate weight loss is common, particularly in African American patients. More study is required to determine the long-term efficacy of the LASGB

Intrathoracic herniation and perforation 18 years after open Nissen fundoplication

Nissen fundoplication is the most commonly performed surgical procedure in the management of gastroesophageal reflux disease. Esophageal and gastric perforations most commonly occur in the perioperative period and carry significant morbidity. We describe a unique case of intrathoracic gastric wrap perforation and its suspected pathophysiology almost two decades after the original procedure.

Ileal pouch anal anastomosis without ileal diversion

OBJECTIVE

To evaluate continued experience with a one-stage stapled ileoanal pouch procedure without temporary ileostomy diversion.

SUMMARY BACKGROUND DATA

Most centers perform colectomy, proctectomy, and ileal pouch anal anastomoses (IPAA) with a protective ileostomy. Following a previous report, the authors performed 126 additional stapled IPAA procedures for ulcerative colitis and familial adenomatous polyposis, of which all but 2 were without an ileostomy. Outcomes in these patients question the need for temporary ileal diversion, with its complications and need for subsequent surgical closure.

METHODS

Two hundred one patients underwent a stapled IPAA since May 1989, 192 as a one-stage procedure without ileostomy, and 1 with a concurrent Whipple procedure for duodenal adenocarcinoma. Patient charts were reviewed or patients were contacted by phone to evaluate their clinical status at least 1 year after their surgery.

RESULTS

Among the patients who underwent the one-stage procedure, 178 had ulcerative colitis (38 fulminant), 5 had Crohn's disease (diagnosed after IPAA), 1 had indeterminate colitis, and 8 had familial adenomatous polyposis. The mean age was 38 +/- 7 (range 7--70) years; there were 98 male patients and 94 female patients. The average amount of diseased tissue between the dentate line and the anastomosis was 0.9 +/- 0.1 cm, with 35% of the anastomoses at the dentate line. With 89% follow-up at 1 year or more (mean 5.1 +/- 2.4 years) after surgery, the average 24-hour stool frequency was 7.1 +/- 3.3, of which 0.9 +/- 1.4 were at night. Daytime stool control was 95% and night-time control was 90%. Only 2.3% needed to wear a perineal pad. Average length of hospital stay was 10 +/- 0.3 days, with 1.5 +/- 0.5 days readmission for complications. Abscesses or enteric leaks occurred in 23 patients; IPAA function was excellent in 19 of these patients (2 have permanent ileostomies). In patients taking steroids, there was no significant difference in leak rate with duration of use (29 +/- 8 with vs. 22 +/- 2 months without leak) or dose (32 +/- 13 mg with vs. 35 +/- 3 mg without leak). Two (1%) patients died (myocardial infarction, mesenteric infarction).

CONCLUSIONS

The triple-stapled IPAA without temporary ileal diversion has a relatively low complication rate and a low rate of small bowel obstruction, provides excellent fecal control, permits an early return to a functional life, and can be performed in morbidly obese and older patients.

Laparoscopic closure of mesenteric defects after Roux-en-Y gastric bypass

Two case reports are presented of incarcerated small-bowel internal hernias through mesenteric defects following Roux-en-Y gastric bypass surgery (one case each of open and laparoscopic). Both patients first presented to physicians unfamiliar with bariatric surgery complaining of vague, cramping midabdominal pain, and the correct diagnosis was not revealed until laparoscopic surgery was performed. Treatment then resulted in quick recoveries. This type of hernia can evade radiologic testing. Prompt clinical recognition and treatment is necessary to prevent small-bowel infarction.

Complementary roles of laparoscopic abdominal exploration and diagnostic peritoneal lavage for evaluating abdominal stab wounds: a prospective study

PURPOSE

To determine the roles of laparoscopic abdominal exploration (LE) and diagnostic peritoneal lavage (DPL) in the evaluation of abdominal stab wounds, we prospectively compared LE with mandatory celiotomy (MC) in 76 patients having anterior abdominal stab wounds penetrating the fascia over a 22-month period.

PATIENTS AND METHODS

Twenty-two patients underwent emergency celiotomy. The remaining patients were subjected to DPL and assigned to treatment by either celiotomy or initial LE with subsequent conversion to open exploration at the discretion of the attending surgeon.

RESULTS

Laparotomy was avoided in 55% of the 31 patients undergoing initial laparoscopy, and this group demonstrated a significant decrease in the incidence of nontherapeutic celiotomy, from 19% to 57% (P < 0.05), as well as decreased length of hospital stay (4 +/- 0.6 v 5.9 +/- 0.4 days; P < 0.05), and total hospital cost ($6119 +/- 756 v $8312 +/- 627; P < 0.05). There were no missed intraabdominal injuries or morbidity from laparoscopy identified in follow-up. The DPL (N = 36) was positive in 11 of the 12 patients with injury requiring surgical repair and was negative in 16 of the 25 patients not requiring repair. The sensitivity and specificity of DPL were 0.91 and 0.64 compared with 1.0 and 0.74 for laparoscopy.

CONCLUSIONS

An algorithm to evaluate stable patients with anterior abdominal stab wounds and minimize overall costs of care, incidence of nontherapeutic celiotomy, and rate of missed injuries is suggested consisting of DPL followed by observation in patients with negative DPL and by laparoscopy in patients with positive DPL. Wounds to the thoracoabdominal region may be best evaluated by initial LE, as diaphragmatic wounds may result in a false-negative DPL.

Laparoscopic intraperitoneal polytetrafluoroethylene (PTFE) prosthetic patch repair of ventral hernia. Prospective comparison to open prefascial polypropylene mesh repair

BACKGROUND

The purpose of this study was to determine whether laparoscopic intraperitoneal polytetrafluoroethylene (PTFE) prosthetic patch (LIPP) repair of a ventral hernia is superior to open prefascial polypropylene mesh (OPPM) repair in a tertiary care university hospital in an urban environment.

METHODS

Data on 39 consecutive patients undergoing either LIPP repair (n = 21) or OPPM repair (n = 18) were compared.

RESULTS

Findings showed that LIPP repair is characterized by less painful recovery and shorter hospital stay, with 90% of patients treated successfully as outpatients as compared with 7% in the OPPM group. The total facility costs for the LIPP repair ($8,273+/-$2,950) was significantly lower than for the OPPM repair ($12,461+/-$5,987) (p<0.05). Two serious delayed complications in the LIPP group were treated by reoperation (colocutaneous fistula, mesh infection), but the higher readmission costs in this group did not negate the overall cost advantage for LIPP repair. In the follow-up evaluation, 1 hernia recurrence was found in the LIPP repair group, and none in the OPPM group.

CONCLUSIONS

Initial experience suggests that LIPP repair has advantages over OPPM repair in terms of decreased hospitalization, postoperative pain, and disability. Refinements in the technique to reduce complications may make LIPP repair the procedure of choice for repair of ventral hernias.

Feasibility of 23-hour hospitalization after laparoscopic fundoplication

PURPOSE

In order to reduce the costs of laparoscopic fundoplication, a pilot program for outpatient surgery was instituted in 1995. The risks and benefits of reducing postoperative hospitalization to < or =23 hours were assessed.

PATIENTS AND METHODS

Patients in ASA grade I or II (N = 22) with refractory gastroesophageal reflux disease underwent laparoscopic fundoplication over a 21-month period in a hospital-affiliated outpatient facility. The results were compared with those of a similar group of 16 patients whose surgery was performed on an inpatient basis.

RESULTS

Seventeen patients (77%) were discharged within 23 hours of surgery. The maximum length of stay was 3 days. There were no deaths. Nineteen patients (86%) reported excellent results. The average facility cost declined from $7,169 for the inpatient group to $4,588 for patients on operated under the outpatient protocol. The decrease resulted from a reduction in the cost of room, operating suite, supplies, and anesthesia.

CONCLUSION

Laparoscopic fundoplication can be performed safely in a hospital-affiliated outpatient setting, resulting in a significant reduction in procedure costs.

Cholesterol enhances membrane-damaging properties of model bile by increasing the intervesicular-intermixed micellar concentration of hydrophobic bile salts

Bile salts are potent detergents that, at concentrations attained in bile and intestine, can disrupt cell membranes. Hepatic secretion of vesicles containing lecithin and cholesterol appears to be critical in preventing bile salt damage to hepatobiliary epithelia. We hypothesize that the protective effect of biliary lipids results from lowering of the bile salt intervesicular intermixed micellar bile salt concentration (IMMC) to which epithelial membranes are exposed. We further hypothesize that increases in biliary cholesterol, by reducing association of bile salts with vesicles and mixed micelles, may increase bile toxicity by raising the bile salt IMMC.

METHOD

Large unilamellar lecithin vesicles (100 nm) with varying cholesterol:lecithin molar ratios (C:L) of 0, 0.5, and 1 were added to taurochenodeoxycholate (TCDCA), taurocholate (TCA), or taurodeoxycholate (TDCA) in Tris-buffered saline, pH 7.4. Human erythrocyte ghosts (model target membrane), prepared by osmotic hemolysis and resealed with [14C]inulin trapped inside, were added and incubated at 37 degrees C for 30 min and 4 h. Plasma membrane disruption was quantified by [14C]inulin release and bile salt IMMC was determined by ultrafiltration.

RESULTS

Membrane disruption started at a concentration of 0.5 mM for TDCA, 1 mM for TCDCA, and 2 mM for TCA and was complete within 4 h at concentrations of 1, 2, and 4 mM, respectively. Addition of 2 mM lecithin to 2 mM TDCA, 4 mM TCDCA, or 5 mM TCA reduced or eliminated membrane leakage and lowered the IMMC. For TDCA and TCDCA, the protective effect of vesicles was entirely attributable to reduction in IMMC; in contrast for TCA, the protective effect exceeded that which would have been expected based solely on reduction of the IMMC. Inclusion of cholesterol attenuated the binding of bile salts to vesicles and raised the IMMC, thereby reducing the protective effect of lecithin over the time course of these studies. Although there was loss of phospholipid and cholesterol from the erythrocyte membranes on addition of bile acids even in the presence of vesicles, the ratio of cholesterol to phospholipid in the erythrocyte membrane did not change.

CONCLUSION

Lecithin protects against membrane disruption by hydrophobic bile salts by lowering the IMMC. Cholesterol added to lecithin raises the bile salt IMMC and reduces or eliminates this protective effect. This mechanism of potentiation of bile salt toxicity by cholesterol may be an important contributor to the pathogenesis of gallbladder disease in cholesterol cholelithiasis.

Gastric surgery for pseudotumor cerebri associated with severe obesity

OBJECTIVE

To study the efficacy of gastric surgery-induced weight loss for the treatment of pseudotumor cerebri (PTC).

SUMMARY BACKGROUND DATA

Pseudotumor cerebri (also called idiopathic intracranial hypertension), a known complication of severe obesity, is associated with severe headaches, pulsatile tinnitus, elevated cerebrospinal fluid (CSF) pressures, and normal brain imaging. The authors have found in previous clinical and animal studies that PTC in obese persons is probably secondary to a chronic increase in intraabdominal pressure leading to increased intrathoracic pressure. CSF-peritoneal shunts have a high failure rate, probably because they involve shunting from a high-pressure system to another high-pressure zone. In an earlier study of gastric bypass surgery in eight patients, CSF pressure decreased from 353+/-35 to 168+/-12 mm H2O at 34+/-8 months after surgery, with resolution of headaches in all.

METHODS

Twenty-four severely obese women underwent bariatric surgery--23 gastric bypasses and one laparoscopic adjustable gastric banding--62+/-52 months ago for the control of severe obesity associated with PTC. CSF pressures were 324+/-83 mm H2O. Additional PTC central nervous system and cranial nerve problems included peripheral visual field loss, trigeminal neuralgia, recurrent Bell's palsy, and pulsatile tinnitus. Spontaneous CSF rhinorrhea occurred in one patient, and hemiplegia with homonymous hemianopsia developed as a complication of ventriculoperitoneal shunt placement in another. There were two occluded lumboperitoneal shunts and another functional but ineffective lumboperitoneal shunt. Additional obesity comorbidity in these patients included degenerative joint disease, gastroesophageal reflux disease, hypertension, urinary stress incontinence, sleep apnea, obesity hypoventilation, and type II diabetes mellitus.

RESULTS

At 1 year after bariatric surgery, 19 patients lost an average of 45+/-12 kg, which was 71+/-18% of their excess weight. Their body mass index and percentage of ideal body weight had fallen to 30+/-5 kg/m2 and 133+/-22%, respectively. In four patients, less than 1 year had elapsed since surgery. Five patients were lost to follow-up. Surgically induced weight loss was associated with resolution of headache and pulsatile tinnitus in all but one patient within 4 months of the procedure. The cranial nerve dysfunctions resolved in all patients. The patient with CSF rhinorrhea had resolution within 4 weeks of gastric bypass. Of the 19 patients not lost to follow-up, 2 regained weight, with recurrence of headache and pulsatile tinnitus. Additional resolved associated comorbidities were 6/14 degenerative joint disease, 9/10 gastroesophageal reflux disorder, 2/6 hypertension, and all with sleep apnea, hypoventilation, type II diabetes mellitus, and urinary incontinence.

CONCLUSIONS

Bariatric surgery is the long-term procedure of choice for severely obese patients with PTC and is shown to have a much higher rate of success than CSF-peritoneal shunting reported in the literature, as well as providing resolution of additional obesity comorbidity. Increased intraabdominal pressure associated with central obesity is the probable etiology of PTC, a condition that should no longer be considered idiopathic.

Lecithin protects against plasma membrane disruption by bile salts

INTRODUCTION

Detergent disruption of epithelial plasma membranes by bile salts may contribute to pathogenesis of cholestasis and gastroesophageal reflux disease. Bile, despite containing high concentrations of bile salts, normally is not toxic to biliary or intestinal epithelia. We hypothesize that lecithin in bile may protect cell membranes from disruption by bile salts.

METHODS

We studied the interactions of taurine conjugates of ursodeoxycholate (TUDCA), cholate (TCA), chenodeoxycholate (TCDCA), and deoxycholate (TDCA) with erythrocyte plasma membranes with or without large unilamellar egg lecithin vesicles for various times at 23 degreesC. Release of hemoglobin was quantified spectrophotometrically. The concentration of bile salt monomers and simple micelles in the intermixed micellar aqueous phase (IMMC) was determined by centrifugal ultrafiltration.

RESULTS

The degree of hemolysis depended on the hydrophobicity of the bile salts and was progressive over time. Addition of lecithin reduced the hemolytic effects of 20 mM TCA or 2 mM TDCA in a concentration-dependent manner at both 30 min and 4 h. Increasing the concentration of lecithin progressively reduced the IMMC of TDCA. Hemolysis following addition of lecithin to 2 mM TDCA was comparable to hemolysis produced by lecithin-free TDCA solutions when diluted to similar IMMC values.

CONCLUSION

We conclude that lecithin reduces plasma membrane disruption by hydrophobic bile salts. This protection may be attributable to association of bile salts with vesicles and mixed micelles, reducing the concentration of bile salt monomers and simple micelles available to interact with cell membranes. Lecithin may play a key role in preventing bile salt injury of biliary and gastrointestinal epithelia.

Laparoscopic hernia repair of an incisional hernia secondary to placement of an implantable cardioverter defibrillator

We present the laparoscopic repair of a large incisional hernia secondary to placement of a subcostal ICD pulse generator. Laparoscopic repair of large incisional hernias provides a unique and technically feasible form of repair in the 2%-13% of patients who will develop an incisional hernia following an abdominal surgery. This form of hernia repair is associated with minimal morbidity and prompt resumption of patient activities and work.

Adjustable laparoscopic gastric band for the treatment of morbid obesity: radiologic evaluation

OBJECTIVE

This article describes the radiographic appearance of a recently developed laparoscopically placed adjustable gastric band for the treatment of morbid obesity. The optimal technique for contrast evaluation of the device, complications associated with its use, and the technique for stoma adjustments are also discussed.

SUBJECTS AND METHODS

Between May and December 1996, 23 patients at our institution underwent laparoscopic placement of adjustable silicone gastric bands for treatment of morbid obesity. All patients underwent a barium upper gastrointestinal series before surgery, 1 day after band placement, at variable intervals when each patient returned for band adjustment, and at 1 year.

RESULTS

Unlike the case in other gastric weight loss procedures, the optimal patient position for contrast evaluation of gastric bands was anteroposterior or slightly right posterior oblique. Twenty-one of 23 patients had no complications shown on the postoperative upper gastrointestinal series. Stoma size was approximately 3-8 mm, and most patients showed delayed esophageal emptying without obstruction. Two patients had herniation of the stomach through the gastric band with pouch enlargement, resulting in obstruction and the need for additional surgery. We saw no leaks or band erosions. Nineteen stoma adjustments were performed in 13 patients. One patient had an inverted port that could not be accessed for adjustment.

CONCLUSION

As adjustable gastric bands become more widely used, radiologists need to be familiar with the radiographic appearance of the devices, the complications associated with their use, and the optimal patient positioning for contrast evaluation. Radiologists may also be involved with band adjustment to decrease or increase the stoma size and therefore need to understand the technique and potential difficulties of adjusting the stoma.

Initial results of a prospective trial of outpatient laparoscopic cholecystectomy

BACKGROUND

Whether or not laparoscopic cholecystectomy may be performed safely as an outpatient procedure is controversial. In 1993, a protocol for outpatient laparoscopic cholecystectomy was instituted to determine the benefits and safety of discharging patients within several hours of surgery.

METHODS

The initial 60 outpatient laparoscopic cholecystectomies performed by one surgeon in a hospital-based outpatient teaching facility between February 1993 to June 1996 were prospectively studied.

RESULTS

Fifty-eight (97%) patients were discharged successfully after an average stay in the recovery room of 3 h. There were no deaths. Two patients required overnight observation and three patients required readmission. Two patients (3%) had cystic duct leak. The average hospital stay for all patients undergoing laparoscopic cholecystectomy at the institution (inpatient and outpatient) decreased from 3.2 to 1.5 days and the average hospital cost decreased from $7,800 to $4,600 during this period.

CONCLUSION

Laparoscopic cholecystectomy in an outpatient setting is safe and cost-effective in healthy patients.

Conversion of proximal to distal gastric bypass for failed gastric bypass for superobesity

The purpose of this study was to analyze outcome following malabsorptive distal gastric bypass (D-GBP) in superobese patients who were reoperated for recurrent obesity comorbidity after a failed standard gastric bypass (S-GBP). Twenty-seven formerly superobese patients with a failed S-GBP converted to a D-GBP were studied. The small bowel was anastomosed 250 cm from the ileocecal valve to the disconnected Roux limb; the bypassed small intestine was connected to the ileum 50 cm from the ileocecal valve in five patients between 1985 and 1986 and 150 cm from the ileocecal valve in 22 patients thereafter. Comorbidity was reassessed yearly following conversion to D-GBP. Malnutrition occurred in all five patients with a 50 cm "common tract"; all required further revision and two died of hepatic failure. Three of 22 patients with a 150 cm common tract were reoperated with bowel lengthening because of malnutrition. Initial body mass index was 57+/-2 kg/m2 and fell from 46+/-2 kg/m2 before revision to 37+/-2 kg/m2 at 1 year and 32+/-2 kg/m2 at 5 years after revision; the percentage of excess weight lost went from 30+/-4% to 61+/-4% at 1 year and 69+/-5% at 5 years after revision. Preoperative comorbidity in patients undergoing revision included 14 with insulin-dependent type II diabetes mellitus, 11 with sleep apnea, 14 with hypoventilation, 13 with hypertension, and two with venous stasis ulcers. Obesity comorbidity was corrected within 1 year in all but two patients with hypertension and remained stable in all patients followed for 5 years. Revision of a failed S-GBP to a 150 cm common tract D-GBP corrects failed weight loss and severe obesity comorbidity but requires nutritional support to prevent protein-calorie malnutrition, iron and fat-soluble vitamin deficiencies, and further revision in some patients to correct malnutrition. A 50 cm common tract has an unacceptable morbidity and mortality.

Increased intra-abdominal pressure and cardiac filling pressures in obesity-associated pseudotumor cerebri

OBJECTIVES

To determine whether intra-abdominal pressure (as estimated from urinary bladder pressure) is elevated in patients with central obesity (as measured by sagittal abdominal diameter) and pseudotumor cerebri and whether this increased intra-abdominal pressure is associated with increased pleural pressure and cardiac filling pressure, implying a resistance to venous return from the brain.

DESIGN

Nonrandomized, prospective.

SETTING

University hospital, operating room.

MAIN OUTCOME MEASUREMENTS

Intracranial pressure, urinary bladder pressure, sagittal abdominal diameter, transesophageal pleural pressure, central venous pressure, pulmonary artery pressure, and pulmonary artery occlusion pressure.

SUBJECTS

Six women with pseudotumor cerebri (one with CSF leak, one with lumboperitoneal shunt).

RESULTS

Urinary bladder pressure (22 +/- 3 cm H2O) and sagittal abdominal diameter (29 +/- 3 cm) were significantly elevated in these patients with elevated intracranial pressure (293 +/- 80 mm H2O) compared with a previously reported group of nonobese control patients. The transesophageal pleural pressure (15 +/- 10 mm Hg), central venous pressure (20 +/- 6 mm Hg), mean pulmonary artery pressure (31 +/- 6 mm Hg), and pulmonary artery occlusion pressure (21 +/- 7 mm Hg) were all markedly elevated compared with published normal values and with previous data from obese patients without pseudotumor cerebri.

CONCLUSIONS

These data support the hypothesis that central obesity raises intra-abdominal pressure, which increases pleural pressure and cardiac filling pressure, which impede venous return from the brain, leading to increased intracranial venous pressure and increased intracranial pressure associated with pseudotumor cerebri.

Laparoscopic Nissen fundoplication for severe gastroesophageal reflux disease: pros and cons

The advent of the laparoscopic approach to Nissen fundoplication has led to a resurgence in enthusiasm for the surgical treatment of gastroesophageal reflux disease (GERD). However, controversy exists as to which subgroups of GERD patients are best treated surgically. The relative success of treatment with medical and surgical intervention in terms of both symptom control and objective resolution of esophageal injury must be weighed against the relative costs of each therapeutic strategy in both the short and long term, given that GERD tends to be a lifelong disorder. The following is the transcribed text of a debate held at the Medical College of Virginia as part of a continuing medical education program in which the statement "Laparoscopic antireflux surgery is superior to medical treatment for severe gastroesophageal reflux disease" was contested. Representatives from the departments of surgery and gastroenterology provided arguments supporting their respective sides of this issue. The purpose was not to promote polarization in treatment selection, but to review the available data in a forum that could promote development of a rational algorithm for clinical decision-making in patients with GERD who might benefit from antireflux surgery. Final comments from the authors are provided in an attempt to synthesize the arguments into a reasonable strategy for individual case management.

Lactic acidosis during sepsis is related to increased pyruvate production, not deficits in tissue oxygen availability

OBJECTIVE

The purpose of this study was to quantitate the derangements in intermediary carbohydrate metabolism and oxygen use in severely septic patients in comparison with healthy volunteers.

SUMMARY BACKGROUND DATA

It commonly has been assumed that the development of lactic acidosis during sepsis results from a deficit in tissue oxygen availability. Dichloroacetate (DCA), which is known to increase pyruvate oxidation but only when tissue oxygen is available, provides a means to assess the role of hypoxia in lactate production.

METHODS

Stable isotope tracer methodology and indirect calorimetry was used to determine the rates of intermediary carbohydrate metabolism and oxygen use in five severely septic patients with lactic acidosis and six healthy volunteers before and after administration of DCA.

RESULTS

Oxygen consumption and the rates of glucose and pyruvate production and oxidation were substantially greater (p < 0.05) in the septic patient compared with healthy volunteers. Administration of DCA resulted in a further increase in oxygen consumption and the percentage of glucose and pyruvate directed toward oxidation. Dichloroacetate also decreased glucose and pyruvate production, with a corresponding decrease in plasma lactate concentration.

CONCLUSIONS

These findings clearly indicate that the accumulation of lactate during sepsis is not the result of limitations in tissue oxygenation, but is a sequelae to the markedly increased rate of pyruvate production. Furthermore, the substantially higher rate of pyruvate oxidation in the septic patients refutes the notion of a sepsis-induced impairment in pyruvate dehydrogenase activity.

Surgically placed gastro-jejunostomy tubes have fewer complications compared to feeding jejunostomy tubes

OBJECTIVE

During laparotomy, jejunostomy tubes (J tubes) are often placed to provide access for enteral nutrition in the immediate postoperative period. However, the placement of such tubes may be associated with potentially devastating intra-abdominal complications possibly related to the tenuous security of a tube through the small bowel wall. An alternative method for enteral nutrition access is to surgically place a "PEG-J" tube (i.e., surgical G/J tube) thus providing for jejunal feedings via a gastrotomy without a jejunotomy. The purpose of this study is to assess whether surgically placed G/J tubes reduce the postoperative complications in comparison to feeding J tubes.

METHODS

Over the past 18 months, 92 J tubes and 56 G/J tubes were placed during laparotomy at a single institution and the method chosen by surgeons' preference. The frequency of complications associated with each tube was determined by review of the postoperative medical records.

RESULTS

There was no enteric leakage in those patient given G/J tubes (p < 0.05). Furthermore 10% of the patients receiving J tubes required operative repair of a J tube complication while no patient with an access complication following G/J tube placement required surgical repair (p < 0.05).

CONCLUSIONS

These results demonstrate that operative positioning of a jejunal feeding tube through a gastrostomy tube (surgical G/J tube) provides a safer route for enteral nutrition than does direct tube placement via the jejunal wall, by significantly reducing both the incidence of enteric leakage and the requirement for operative repair.

Conversion of failed or complicated vertical banded gastroplasty to gastric bypass in morbid obesity

BACKGROUND

Previous studies have documented a significantly better we weight loss for gastric bypass (GBP) than for vertical banded gastroplasty (VGB). Additional problems associated with VBG include intractable vomiting or gastroesophageal (GE) reflux, intragastric migration of the polypropylene band, staple line disruption, or inadequate weight loss due to excessive ingestion of high-calorie liquid or soft carbohydrates.

PATIENTS AND METHODS

Fifty-eight morbidly obese patients underwent conversion from VBG to GBP for either weight-loss failure (15) or complications of VBG (43), including 2 who where referred with anastomotic leaks and peritonitis, 3 with band erosion, 15 with staple line disruption, and 23 with stomal stenosis, of whom 6 had severe GE reflux, with a Barrett's esophagus in 1.

RESULTS

Percentage of excess weight loss in the 53 patients followed up for at least 1 year after conversion increased from 36% +/- 24% to 67% +/- 18%, and in the 15 "sweets eaters" from 20% +/- 19% to 70% +/- 19% (both P <0.001), was equal to weight loss after primary GBP, and was reasonably constant over 8 years in those patients who could be contacted for follow-up, although average follow-up after 5 years was only 45% All patients had resolution of GE reflux symptoms immediately after surgery and for at least 1 year or at last contact. Complications of conversion included 2 anastomotic leaks with major wound infections (1 in a referred patient requiring emergency subtotal gastrectomy following a VBG leak), 3 staple line disruptions (2 subclinical), 3 small-bowel obstructions, and 20 marginal ulcers or stomal stenoses (all responded to endoscopic balloon dilation or acid reduction therapy). Hemoglobin, calcium, and vitamin B12 levels remained within normal levels with prophylactic supplementation in patients who returned for follow-up evaluation.

CONCLUSIONS

These data support the efficacy of conversion to GBP in morbidly obese patients with a failed or complicated VBG.

Greater risk of incisional hernia with morbidly obese than steroid-dependent patients and low recurrence with prefascial polypropylene mesh

BACKGROUND

Incisional hernia is a serious complication of abdominal surgery. We compared incisional hernia frequency following gastric bypass (GBP) for morbid obesity versus total abdominal colectomy and ileal pouch-anal anastomosis (IPAA) for ulcerative colitis. A prefascial polypropylene mesh repair was also evaluated.

PATIENTS AND METHODS

All patients had midline incisions, xiphoid to umbilicus in GBP patients and midepigastrium to pubis in IPAA patients. Fascia were closed with running No. 2 polyglycolic acid suture. Ninety-eight patients underwent prefascial polypropylene mesh repair; 80 were GBP patients, 46 had 1 previous repair, and 17 had 2 to 9 previous repairs (6 with properitoneal mesh).

RESULTS

Incisional hernia occurred in 20% (198/968) of GBP patients (19% without versus 41% with a previous hernia, P < 0.001) versus 4% (7/171) of the IPAA patients (P < 0.001), of whom 102 (60%) were taking prednisone (32 +/- 2 mg/d) and 5 were quite obese (body mass index > or = 30 kg/m2). Additional risk factors for hernia in GBP patients included wound infection, diabetes, sleep apnea, and obesity hypoventilation. For the 98 patients who underwent prefascial polypropylene mesh repair, the mean follow-up was 20 +/- 2 months (range 6 to 104), and complications occurred in 35% of patients, including minor wound infection (12%), major wound infection (5%), seroma (5%), hematoma (3%), chronic pain (6%), and recurrent hernia (4%).

CONCLUSIONS

Severe obesity is a greater risk factor for incisional hernia and hernia recurrence than chronic steroid use in nonobese colitis patients. A prefascial polypropylene mesh repair minimizes recurrence.

Treatment of increasing intracranial pressure secondary to the acute abdominal compartment syndrome in a patient with combined abdominal and head trauma

Acute abdominal compartment syndrome has recently been shown to raise intracranial pressure (ICP). This may increase the risk of ischemic neuronal damage by decreasing cerebral perfusion pressure. We report the successful management of a patient with severe multisystem injury in whom abdominal decompression dramatically reduced high ICP unresponsive to medical measures.

Except for alanine, muscle protein catabolism is not influenced by alterations in glucose metabolism during sepsis

OBJECTIVE

To assess any relationship between hyperglycemia and muscle protein catabolism associated with critical illness.

DESIGN

Cohort analytic study.

SETTING

Clinical research center and intensive care unit of a university hospital.

PARTICIPANTS

Six healthy volunteers and five patients with severe sepsis.

INTERVENTIONS

Study subjects were given infusions of 6,6,d2 glucose and 15N lysine for 6 hours. After infusion of the stable isotopes for 2 hours (basal period), dichloroacetate, which accelerates pyruvate oxidation, was given (dichloroacetate period). Leg blood flow was measured by indocyanine green dye dilution, and femoral artery and vein substrate concentrations were quantitated.

MAIN OUTCOME MEASURES

The metabolic rates of glucose production, oxidation, and clearance; the whole-body protein breakdown rate; and the net efflux of amino acids from the leg were determined.

RESULTS

In comparison with the healthy volunteers, septic patients had significant elevations in glucose production, oxidation, and clearance, accelerated protein catabolism, and greater net peripheral efflux of amino acids. Dichloroacetate significantly decreased glucose production and increased the percentage of glucose directed toward oxidation in both healthy volunteers and septic patients. However, this dichloroacetate-induced perturbation of glucose utilization had no significant effect on whole-body protein breakdown or the efflux of specific amino acids from the leg except for alanine, whose net efflux doubled (P < or = .05).

CONCLUSIONS

The findings of this study demonstrate a universal acceleration in the metabolic rates of both intermediary glucose metabolism and protein/amino acid catabolism during sepsis. Except for alanine, however, there appears to be no coupling between these two physiologic responses to sepsis.

Decreased splanchnic perfusion measured by duplex ultrasound in humans undergoing small volume hemorrhage

OBJECTIVES

To quantitate duplex Doppler measurements of splanchnic perfusion to determine if these measurements are reproducible in euvolemic humans and if such measurements are sensitive to mild degrees of systemic hypovolemia.

DESIGN

Prospective, nonrandomized, controlled trial.

SETTING

Clinical research center.

PARTICIPANTS

Seven fasting, healthy male and female volunteers, ranging in age from 25 to 37 yrs and weighing 60 to 90 kg.

INTERVENTIONS

Pulse, blood pressure, hematocrit, and duplex Doppler measurements of the peak systolic velocity and time averaged velocity of the subdiaphragmatic aorta, celiac artery, and superior mesenteric artery were obtained at four time points. Time points I and II were on separate days before hemorrhage and consisted of routine blood donation of 450 mL. Time point III was immediately after blood donation. Time point IV was 24 hrs after donation. Estimated blood flow was calculated from time averaged velocity (estimated blood flow = 60[vessel cross-sectional area][time averaged velocity]).

MEASUREMENTS AND MAIN RESULTS

Vital signs and hematocrit remained without significant change at all time points. Peak systolic velocity, time averaged velocity, and estimated blood flow were also unchanged between measurements at time points I and II. However, after a mean reduction of 9.1% of total blood volume, duplex ultrasound detected significant decreases of 14.5% in celiac artery and superior mesenteric artery peak systolic velocity, as well as 15.1%, 17.3%, and 20.2% decreases in aorta, celiac artery and superior mesenteric artery time averaged velocity and estimated blood flow, respectively (all values p < .05 vs. baseline, Duncan's multiple range test). All measured variables returned to baseline 24 hrs after hemorrhage.

CONCLUSIONS

Noninvasive duplex Doppler measurements of splanchnic peak systolic velocity, time averaged velocity, and estimated blood flow are reproducible and sensitive to small changes in intravascular volume. These data suggest a potential clinical role for duplex imaging in the treatment of critically ill patients to guide therapy to optimize splanchnic perfusion.

Laparoscopic bilateral inguinal hernia repair under local anesthesia

A case report of the laparoscopic repair of bilateral inguinal hernias performed under local anesthesia with intravenous sedation is presented. The combination of nitrous oxide for peritoneal insufflation and an ultrasonically activated scalpel for dissection made the procedure feasible. It is hoped that this technique can extend laparoscopic surgery to patients who are poor candidates for general anesthesia.

The role of inflammatory cytokines in wound healing: accelerated healing in endotoxin-resistant mice

The role of cytokines in normal wound healing remains poorly defined. In vitro, tumor necrosis factor alpha (TNF-alpha) decreases collagen accumulation, perhaps by increasing collagenase activity. The current study was undertaken to test the hypothesis that cytokines impair wound healing and collagen production. Wounds in C3H/HeJ (J) mice, which are characterized by a genetic defect in macrophage production of TNF and other cytokines in response to endotoxin, were compared with wounds in normal endotoxin-sensitive C3H/HeN (N) mice.

METHODS

TNF (by murine ELISA) and collagenolytic activity (CA by in vivo labelled collagen fibril degradation assay) were measured in wound fluid from silicone reservoirs on post-wounding days 1, 3, and 5 (n = 5 per group). Hydroxyproline (HOP, nmol/mg sponge) incorporation (by HPLC) in polyvinylacohol sponges and breaking strength (BS, as determined by tensiometry) in linear wounds were assessed on days 5, 7, 10, and 14 (n = 5 per group). The data demonstrate significantly increased BS at 5 and 7 days in endotoxin-resistant J mice compared with that in endotoxin-sensitive N mice. An early, significant reduction in TNF production in J mice corresponded with a significant increase in CA on day 1, increased collagen production at day 7, and increased procollagen gene transcription at early time points. Conclusion. The reduced production of inflammatory cytokines including TNF in the wound fluid of J mice corresponded with an early improvement in wound tensile strength. An accelerated accumulation of collagen in the wounds of J mice, perhaps resulting from a significant decrease in collagenolytic activity or increased collagen production, are potential mechanisms. The data suggest that cytokines produced in normal healing of clean wounds may contribute to a delay in increased tensile strength.

Decreased lactate in endotoxin-resistant mice undergoing hemorrhage is independent of tumor necrosis factor availability

Although C3H/HeJ mice, characterized by a genetic deficiency in macrophage cytokine release in response to endotoxin, have been studied extensively to gain insight into the possible role of various cytokines in sepsis, few past studies have examined the physiologic response to hemorrhagic shock in this "endotoxin-resistant" strain. We utilized a fixed-volume model of hemorrhagic shock and two different levels of hemorrhage severity (50 and 67% blood volume) to compare C3H/HeJ mice to normal C3H/HeN mice. An additional group of endotoxin-sensitive C3H/HeN mice were treated with 2.5 mg/kg of anti-tumor necrosis factor (TNF) antibody to define the possible role of TNF in shock physiology. Hematocrit, circulating neutrophils, and plasma glucose and lactate concentrations were measured following hemorrhage. TNF increased significantly following hemorrhage in normal mice but did not increase in C3H/HeJ mice or in C3H/HeN mice treated with anti-TNF antibody. No difference between groups was identified in hematocrit, circulating neutrophils, or glucose. Whereas plasma lactate increased significantly by 30 min in all groups, lactate returned to baseline levels in C3H/HeJ mice at 60 min, but remained persistently elevated in C3H/HeN mice and in C3H/HeN mice treated with anti-TNF antibody. The data demonstrate attenuated lactate accumulation in C3H/HeJ mice following hemorrhage. Inhibition of circulating TNF activity with anti-TNF antibody failed to reproduce this late decrease in plasma lactate in normal mice. The data suggest that macrophage products other than TNF known to be deficient in C3H/HeJ mice contribute to anaerobic metabolism in hemorrhagic shock.

Hemorrhagic shock in endotoxin-resistant mice: improved survival unrelated to deficient production of tumor necrosis factor

Although tumor necrosis factor (TNF) has been implicated in sepsis-induced mortality, its role in the pathophysiology of hemorrhagic shock (HS) remains ill defined. We studied three groups of acutely anesthetized mice undergoing HS to determine the role of TNF in HS mortality. Shock was initiated in each group after heparinization by arterial bleeding of 4 mL/100 g body weight followed by 12 mL/100 g body weight resuscitation with normal saline at 1 hour. The C3H/HeJ mice (n = 14), characterized by a genetic defect in macrophage production of TNF and other cytokines in response to endotoxin, were compared with the closely related C3H/HeN strain (n = 18), which do produce TNF. A second group of C3H/HeN mice were passively immunized to TNF by pretreatment with 2.5 mg/kg anti-murine TNF antibody (Ab) before HS. In contrast to the high TNF levels measured following HS in C3H/HeN controls, post-HS TNF was undetectable in C3H/HeJ mice. Five-day survival rate and survival time were significantly greater in C3H/HeJ mice when compared with C3H/HeN controls. Anti-TNF Ab pretreatment of C3H/HeN mice abolished the increase in TNF but did not improve survival. The data demonstrate a striking improvement in survival of TNF-deficient C3H/HeJ mice following severe HS. However, the improved survival does not appear to result from deficient TNF production, since Ab pretreatment did not decrease HS mortality. The improved survival in C3H/HeJ mice suggests that cytokines other than TNF may play a role in the pathophysiology of HS.

Interleukin-1 receptor antagonist improves survival and preserves organ adenosine-5'-triphosphate after hemorrhagic shock

BACKGROUND

This study was designed to determine the role of interleukin-1 (IL-1) in hemorrhagic shock death.

METHODS

Pentobarbital anesthetized C3H/HeN mice (n = 59) were prepared with a femoral arterial catheter and were randomized to treatment with an IL-1 receptor antagonist (IL-1ra, 10 mg/kg, n = 29) or an equal volume of phosphate-buffered saline solution (vehicle, n = 30) by subcutaneous bolus injection at 15 minutes before hemorrhage and again at 120 minutes. Continuous posthemorrhage delivery of IL-1ra or vehicle was performed in each group (1.5 mg IL-1ra in 30 microliters/day) through a subcutaneous osmotic pump. Rapid hemorrhage of 4 ml/100 gm weight was followed by normal saline resuscitation of 12 ml/100 gm 60 minutes later.

RESULTS

Survival analysis by Wilcoxon rank sum analysis revealed a significantly improved 5-day survival in IL-1ra-treated mice (n = 15, 20%) as compared with vehicle-treated mice (n = 14, 6%, p < 0.001). To determine a possible mechanism of this survival advantage, the remaining mice in each treatment group were killed at 30 minutes to obtain blood and tissue samples from the heart, liver, and kidney for measurement of adenosine-5'-triphosphate (ATP). No difference in hematocrit, circulating neutrophils, or levels of glucose, lactate, or tumor necrosis factor was identified between groups to explain the improved outcome. IL-1ra prevented hemorrhage-induced ATP depletion observed in vital organs of vehicle-treated mice.

CONCLUSIONS

The data implicate IL-1 in shock-induced ATP depletion and suggest IL-1ra may improve hemorrhagic shock survival by preventing ATP depletion in vital organs.

Evaluation and treatment of the elderly trauma victim

This article examined issues in the care of the injured elderly patient. Past studies have documented variable potential for functional recovery in survivors of serious trauma in the elderly population, and trauma care for this subgroup uses health care resources at an exaggerated rate. Excessive health care costs arise from increased postinjury morbidity and mortality in the elderly population; factors that predict mortality include injury severity, advanced age, and complications. Recent work has focused on the frequency of preventable complications, particularly critical care management errors, in trauma patients of all ages. It appears that the impact of preventable complications on mortality may be greatest in the geriatric trauma victim. Current recommendations for care of these patients include aggressive treatment of all injuries according to standard trauma practice. Routine ICU admission with a low threshold for the institution of invasive monitoring to guide therapy is recommended for all geriatric trauma victims with moderate to more serious injury. The development of specialized management approaches for care of the injured elderly patient will result from ongoing study of this population, as research efforts provide more information about the physiologic and metabolic responses to injury in the elderly population.

Blunt colonic injury--a multicenter review

During the past decade there has been a shift in the management of injuries of the colon to primary repair without a protective diverting colostomy. Unfortunately, reports concerning this practice contain relatively few patients with blunt trauma and it is unclear whether the principles established for penetrating injury should be applied in the setting of blunt colon injury. A retrospective review of 54,361 major blunt trauma patients admitted to nine regional trauma centers from January 1, 1986, through December 31, 1990, was conducted. Statistical analysis of the data collected regarding 286 (0.5%) of these patients who suffered colonic injury revealed: (1) injury to the colon is found in more than 10% of patients undergoing laparotomy following blunt trauma; (2) available diagnostic modalities are unreliable in detecting isolated colonic pathology; (3) primary repair of full-thickness injuries or resection and anastomosis may be safely performed without diversion; (4) gross fecal contamination is the strongest contraindication to primary repair. Further, delay of surgery, shock, and the timing of antibiotic administration were not associated with significantly increased morbidity.

Preventable complications and death from multiple organ failure among geriatric trauma victims

We reviewed 374 consecutive trauma patients over age 65 years to determine (1) if the emergency room Trauma Score (TS) could predict mortality, thereby improving ICU triage, and (2) the frequency of preventable complications in patients who died (n = 31). Fifty-two percent of deaths (n = 16) occurred in patients with TS = 15 or 16. Multiple organ failure/sepsis (MOF/S) was the most common cause of death overall (42%) and was also the most frequent cause of death in patients with a TS = 15-16 (63%). Nonsurvivors in the TS = 15-16 subgroup were older (80.9 +/- 2.0 vs. 74.9 +/- 0.5 years, p less than 0.02) and had greater ISSs (15.8 +/- 3.7 vs. 8.0 +/- 0.4, p = 0.001) than survivors. Patients with a TS less than 15 suffered high overall mortality (45%). Preventable complications contributed to mortality in 32% of all deaths and in 62% of MOF/S deaths. Aggressive care to prevent avoidable complications may improve survival in elderly trauma victims.

Coronary vasomotor dysfunction following hemorrhagic shock

Myocardial dysfunction and subendocardial ischemia have been described during hemorrhagic shock, but technical limitations have precluded the in vitro examination of coronary reactivity following hemorrhage. We tested the hypothesis that in vitro coronary artery contraction and relaxation are impaired by hemorrhagic shock (HS). HS was produced in awake rats (n = 6) 24 hr after surgery for arterial cannulation, by bleeding to a mean arterial pressure of 50 mm Hg for 2 hr followed by reinfusion of shed blood. Using a small vessel myograph, reactivity of coronary arterial ring segments from three groups of rats not undergoing HS were compared to coronaries harvested from rats after HS (Group 4). The three nonshock treatments included normal rats without pretreatment (Group 1), rats undergoing prior surgical cannulation alone (Group 2), and rats undergoing prior surgical cannulation followed by nonhypotensive hemorrhage (Group 3). Responses to 125 mM potassium (KCl) and to 10(-6) M serotonin (STN) determined smooth muscle contraction. Acetylcholine administration determined endothelium-mediated smooth muscle relaxation, whereas acetylcholine plus nitroprusside combined determined maximum smooth muscle relaxation. Rats following HS demonstrated impaired coronary arterial smooth muscle contraction to KCl when compared to normal rats, but the response to STN did not differ among groups. Maximum smooth muscle relaxation was significantly lower in rats following HS as compared to rats in Groups 1 and 2. Endothelium-dependent relaxation was significantly impaired when compared to each of the three nonshock groups. Thus, in coronary arteries isolated from neurohumoral influences, HS was associated with diminished smooth muscle contraction and relaxation as well as impaired endothelium-mediated relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of patients with indeterminate diagnostic peritoneal lavage results following blunt trauma

The management of blunt trauma victims with indeterminate diagnostic peritoneal lavage (DPL) findings remains controversial. We reviewed 1,196 patients undergoing DPL to identify patients with indeterminate DPL (red cell counts of 20,000 to 99,999 rbc/mm3). Only 4% (48%) had indeterminate DPL results. Repeat DPL (R-DPL) was performed in 31 patients. Six repeat DPLs produced positive results (greater than 100,000 rbc/mm3), 15 produced indeterminate results, and 10 produced negative results (less than 20,000 rbc/mm3). A review of the nine laparotomies performed in this group revealed only two operations that were therapeutic. Twelve patients had abdominal CT scans following indeterminate DPL. Six patients had negative CT scans and were successfully managed without operation. The findings were positive on six other CT scans. Four patients with positive CT scans, including two splenic injuries, one liver injury, and one renal laceration, were managed successfully without surgery. The remaining two patients with positive CT scans underwent laparotomy. The first had a renovascular injury diagnosed from the CT scan after negative findings on repeat DPL. The second had a minor splenic injury diagnosed from the CT scan. A subsequent repeat DPL produced a positive result prompting a nontherapeutic operation. Eleven patients were observed without repeat DPL or CT scanning. Of these, four eventually underwent laparotomy on the basis of clinical suspicion alone. Only one of these patients required therapeutic intervention at the time of laparotomy. Intra-abdominal injury was common in patients with indeterminate DPL results, however, only four (8%) of the patients required a therapeutic operation. Both negative repeat DPL results or negative findings on CT scans predicted successful nonoperative management.(ABSTRACT TRUNCATED AT 250 WORDS)

Trauma care for the elderly?

The enormous consumption of health-care resources by bluntly injured elderly patients can be justified if their outcome after trauma is good. In this series, 89% of injured elderly patients ultimately returned to their homes, either independent of (57%) or dependent on (32%) outside help. Factors contributing to increased mortality in such patients included age, injury severity, and the presence or absence of cardiac and septic complications. A Geriatric Trauma Survival Score (GTSS) was devised that predicted the likelihood of mortality in these patients. Finally, study of reimbursement indicated that Medicare does not adequately reimburse hospitals for the enormous cost of providing elderly trauma care.

Continuous measurement of atrial volume with an impedance catheter during positive pressure ventilation and volume expansion

Right atrial volume (RAV) and other hemodynamic parameters were measured in ten anesthetized swine with an impedance catheter in the right atrium during ventilation and increasing levels of positive end-expiratory pressure (PEEP) to determine the effects of PEEP on right atrial dynamics. RAV and cardiac output (CO) decreased progressively during ventilation with 5, 10 and 15 centimeters of water PEEP, whereas central venous pressure and pulmonary capillary wedge pressure increased. Despite this decrease in RAV, atrial ejection fraction increased significantly and active atrial output (AAO equals stroke volume times heart rate) was maintained. Thus, the decrease in CO resulted from a decrease in the passive component of ventricular filling. Compensatory increases in AAO helped to minimize the fall in CO in some swine (r = 0.73, p less than 0.01). Peripheral adenocorticotropin (ACTH) increased from 14.0 +/- 4.5 picograms per milliliter at zero centimeters of water PEEP to 46.8 +/- 18.3 picograms per milliliter at 10 centimeters of water PEEP (p less than 0.05). Volume expansion that restored CO to control levels despite PEEP led to a significant increase in RAV and in passive ventricular filling, as well as a decrease in ACTH to 11.2 +/- 1.5 picograms per milliliter (p less than 0.05). Changes in the ACTH levels correlated with changes in the RAV (r = 0.58, p less than 0.05), but did not correlate with changes in CO, arterial pressure or central venous pressure. The data herein suggest that the decrease in CO with PEEP results from decreased venous return, RAV and passive ventricular filling, whereas a compensatory increase in right atrial contractility helps to maintain CO. Ventilation with PEEP stimulates hormonal secretion that can be terminated by adequate volume expansion.

Aldosterone secretion following non-hypotensive hemorrhage is potentiated by prior blood loss

Aldosterone is a major regulator of fluid and electrolyte balance after hemorrhage and is released from the adrenal cortex by the action of adrenocorticotropin (ACTH) and angiotensin II (AII). Past work has shown that the hemorrhage-induced release of ACTH and cortisol is potentiated by prior hemorrhage. We therefore studied the response of adrenal aldosterone secretion to repeated hemorrhage and its control by ACTH and AII. Six awake dogs with chronic lumboadrenal vein catheters were bled 10% of measured blood volume (H1) with reinfusion at 30 minutes. The hemorrhage was repeated 5 hours later (H2). Adrenal presentation rates for AII (AII-PR) and ACTH (ACTH-PR) were calculated for each sample. Control hormonal and hemodynamic parameters before each hemorrhage were not different; hemodynamic responses to H1 and H2 did not differ. Aldosterone secretion increased significantly after each hemorrhage. The increase in aldosterone secretion after H1 was associated with an early increase in AII-PR and late increase in ACTH-PR. Aldosterone secretion following H2 was greater than that following H1 and was associated with early and larger responses of AII-PR and ACTH-PR. Aldosterone secretion following H1 correlated with the AII-PR (r = 0.75; p less than 0.001), but not with the ACTH-PR. In contrast, aldosterone secretion following H2 correlated with both the AII-PR (r = 0.54; p less than 0.01) and ACTH-PR (r = 0.71; p less than 0.001) and multiple regression analysis showed a highly significant relation with both AII and ACTH (r = 0.81; p less than 0.001). The data suggest that aldosterone secretion after initial small hemorrhage occurs as a result of increased AII, whereas both AII and ACTH may contribute to the larger aldosterone secretory response to H2. Since major trauma commonly involves at least two insults separated in time (e.g., injury followed by surgery), potentiated responses of aldosterone and other pituitary-adrenal hormones (ACTH, vasopressin, and cortisol) may have important implications for the control of fluid and electrolyte balance and metabolism in injured patients.

Potentiated cortisol response to paired hemorrhage: role of angiotensin and vasopressin

Potentiated adrenocorticotropin (ACTH) and cortisol responses occur after the second of two small hemorrhages (hems) spaced 24 h apart in the dog. To test whether increased responses of other hormones might be associated with this effect, we examined plasma renin activity (PRA), angiotensin II (ANG II), and vasopressin after paired 10% hem (H1 and H2) spaced 5 h apart in chronically prepared conscious dogs. Cortisol secretion increased after each hem, and the response to H2 was larger (P less than 0.05; H1 peak at 6.8 +/- 1.3 micrograms/min vs. H2 peak at 18.3 +/- 5.3 micrograms/min). ACTH did not change after H1 but increased after H2, and the H2 response was larger (P less than 0.01). Vasopressin increased after each hem, and the H2 response was larger (P less than 0.01). The time courses of ACTH and vasopressin responses were similar after H2 (significant increases by 8 min). PRA and ANG II increased by 4 min after each hem, and although the difference was small the early PRA and ANG II responses were greater after H2. Blood volume and hem volume did not differ between hems. Hemodynamic responses to the hems were not different. We conclude that, although the PRA and ANG II respond rapidly enough after hem to influence pituitary responses, the slightly greater responses of these factors to H2 are not responsible for greatly increased pituitary-adrenal responses to H2. On the other hand, the markedly potentiated vasopressin response to H2, which parallels that of ACTH, suggests that vasopressin may mediate the increased ACTH responses to H2.

Atrial peptide release after hemorrhage in unanesthetized swine

Hemorrhage of 14 ml/kg in 5 min was done in two groups of chronically prepared, splenectomized Yorkshire pigs. Group 1 was studied on post-operative day 4 and was conditioned behaviorally with "active restraint", whereas group 2 was studied on postoperative day 6 and was conditioned with behavioral "shaping." The peak decrease in blood volume occurred by 0.25 h after hemorrhage in both groups. However, plasma atrial natriuretic factor (ANF) as measured by radioimmunoassay did not decrease significantly until 2 h in group 1 and 0.5 h in group 2 even though the recovery of blood volume was significantly more rapid in group 1 than in group 2. The responses of ANF differed significantly between groups, suggesting that ANF release after hemorrhage is influenced by prior handling and the time for recovery from surgery. In both groups, some pigs showed increases in ANF during the 1st h after hemorrhage, and changes in ANF were unrelated to decreases in central venous pressure or absolute right atrial volume determined with a conductance catheter. In contrast, changes in ANF after hemorrhage correlated positively with several variables including atrial rate and changes in vasopressin. Multiple regression suggested that the effect of reduced atrial volume on ANF release was opposed by these latter variables or related factors. Furthermore, known actions of ANF do not appear to account for the observed hemodynamic and hormonal responses to hemorrhage.