Sarcopenia and outcomes in ventral hernia repair: a preliminary review.

PURPOSE: Sarcopenia, or loss of muscle mass, is associated with increased morbidity and mortality in oncologic resections and several other major surgeries. Complex ventral hernia repairs (VHRs) and abdominal wall reconstruction are often performed in patients at high risk for morbidity and recurrence, though limited data exist on outcomes related to sarcopenia. We aimed to determine if sarcopenia is associated with worse outcomes in patients undergoing VHR. METHODS: We reviewed patients undergoing VHRs from 2014 to 2015. Preoperative CT images were analyzed for cross-sectional muscle mass. Patients with and without sarcopenia underwent statistical analysis to evaluate differences in perioperative morbidity and hernia recurrence. Muscle indices were analyzed independently for outcomes. RESULTS: 135 patients underwent VHR with/without fistula takedown, staged repairs or other concomitant procedures. 27% had sarcopenia (age 34-84, BMI 27-33, 62% male). Postoperative complications occurred in 43% of sarcopenic patients and 47% of non-sarcopenic patients (p = 0.70). Surgical site infections (SSI) were seen in 16% of sarcopenic patients compared to 29% without sarcopenia (p = 0.14). There was no difference in hernia recurrence between groups (p = 0.90). However, after adjusting for diabetes and BMI, a 10 cm2/m2 decrease in muscle index had 1.44 OR of postoperative complications (p < 0.05). CONCLUSIONS: Though prevalent in our population, sarcopenia was not associated with an increase in postoperative complications, surgical site occurences/infections,  or hernia recurrence when previously published oncologic sarcopenia cutoffs were utilized. Previously established sarcopenia outcomes in malignancy may be attributable to an altered metabolic state that is not present in hernia repair patients. Larger-scale studies are recommended to establish new sarcopenia cutoffs for VHRs.

Guidelines for nutrition therapy in critical illness: are not they all the same?

In general, clinical guidelines identify, summarize, and evaluate the most current data concerning prevention, diagnosis, prognosis, therapy and cost for a specific patient population. This paper will briefly describe the authors' point of view regarding controversial aspects of adult critical care nutrition therapy guidelines published by preeminent professional societies in the United States (US), Canada, and Europe. The US guidelines were developed by subject matter experts to offer recommendations for specialized nutrition therapy that are supported by review and analysis of the pertinent current literature, other national and international guidelines, and by a blend of expert opinion and clinical practicality. A similar strategy was used to compile all three guideline publications resulting in many areas of common agreement, but disparate substantive recommendations do exist regarding: indirect calorimetry versus predictive equations, prokinetics in the intensive care unit (ICU), arginine use in the ICU, probiotic use in the ICU, and acceptable gastric residual volumes in the ICU patient. All of the guidelines are based on high quality studies in patients with critical illness, but like any other therapeutic modality for an ICU patient, nutritional interventions require a multidisciplinary approach that incorporates institutional best practices, individual patient considerations, and above all, clinical judgment.

The increased incidence of intraabdominal infections in laparoscopic procedures: potential causes, postoperative management, and prospective innovations.

We conducted a review of the literature to identify some potential causes for the increased incidence of intraabdominal infections seen after laparoscopic procedures. We also discuss the postoperative management of this condition and provide a prospective overview of innovations that may be helpful in such cases in the future.

Cloning and functional characterization of a new subtype of the amino acid transport system N.

We have cloned a new subtype of the amino acid transport system N2 (SN2 or second subtype of system N) from rat brain. Rat SN2 consists of 471 amino acids and belongs to the recently identified glutamine transporter gene family that consists of system N and system A. Rat SN2 exhibits 63% identity with rat SN1. It also shows considerable sequence identity (50-56%) with the members of the amino acid transporter A subfamily. In the rat, SN2 mRNA is most abundant in the liver but is detectable in the brain, lung, stomach, kidney, testis, and spleen. When expressed in Xenopus laevis oocytes and in mammalian cells, rat SN2 mediates Na(+)-dependent transport of several neutral amino acids, including glycine, asparagine, alanine, serine, glutamine, and histidine. The transport process is electrogenic, Li(+) tolerant, and pH sensitive. The transport mechanism involves the influx of Na(+) and amino acids coupled to the efflux of H(+), resulting in intracellular alkalization. Proline, alpha-(methylamino)isobutyric acid, and anionic and cationic amino acids are not recognized by rat SN2.

Differential influence of cAMP on the expression of the three subtypes (ATA1, ATA2, and ATA3) of the amino acid transport system A.

Treatment of HepG2 cells with forskolin led to 60-100% stimulation of system A activity, measured as the Na+-dependent uptake of alpha-(methylamino)isobutyric acid. The stimulation was reproducible with cholera toxin and dibutyryl cAMP, and inhibitable by H7, a non-specific protein kinase inhibitor. The stimulatory effect was eliminated by cycloheximide and actinomycin D. The forskolin effect was associated with an increase in the maximal velocity of the transport system, with no change in substrate affinity. These cells express three different subtypes of system A (ATA1, ATA2, and ATA3). Treatment with forskolin increased the steady-state levels of ATA1 and ATA2 mRNAs, but decreased that of ATA3 mRNA.

Solitary fibrous tumors arising in abdominal wall hernia sacs.

Solitary fibrous tumor (SFT) of the peritoneum is an unusual spindle-cell neoplasm. SFT was originally described in the pleura; however it is now diagnosed in multiple extrathoracic sites. Most believe that the tumor is of mesenchymal origin and should be classified as a variant of fibroma. SFT of the pleura and peritoneum have also been called fibrous mesothelioma, and the cell of origin is felt to be a pluripotential submesothelial mesenchymal cell. Primary tumors arising in hernia sacs are rare, and we report on two patients with hernia SFT. The first is a 67-year-old man who had a diffusely thickened distal left inguinal hernia sac. Within the sac was copious myxoid material mimicking pseudomyxoma peritonei. Herniorrhaphy and orchiectomy were performed. The second is a 44-year-old woman with a midepigastric mass attached to a ventral hernia. Wide local excision was performed. Both tumors demonstrated plump spindle cells, one with myxoid background and the other with keloidal collagen. Calretinin immunostaining was positive in both tumors, whereas CD34 was negative. This suggests tumor origin from a submesothial pluripotential cell that maintains potential for mesothelial differentiation. Surgical excision is the treatment of choice with the degree of resectability being a powerful predictor of outcome.

Typical versus atypical presentation of obturator hernia.

Although it is a rare occurrence among all pelvic hernias diagnosed the obturator hernia continues to be a diagnostic challenge for surgeons today. These patients, who often have multiple concurrent medical problems, are subject to high morbidity and mortality rates resulting from late presentation and delayed surgical intervention. The vast majority of patients with obturator hernias are admitted with signs and symptoms of intestinal obstruction, namely anorexia, nausea, vomiting, constipation, and distension of 2 to 3 days' duration. In this paper, however, we highlight a small subset of obturator hernia patients who present without obstructive symptoms and do well after elective repair. The case reports that follow serve to compare and contrast two very different presentations of this surgical problem.

Structure, function, and tissue expression pattern of human SN2, a subtype of the amino acid transport system N.

We have cloned a new subtype of the amino acid transport system N from a human liver cell line. This transporter, designated SN2, consists of 472 amino acids and exhibits 62% identity with human SN1 at the level of amino acid sequence. SN2-specific transcripts are expressed predominantly in the stomach, brain, liver, lung, and intestinal tract. The sizes of the transcripts vary in different tissues, indicating tissue-specific alternative splicing of the SN2 mRNA. In contrast, SN1 is expressed primarily in the brain and liver and there is no evidence for the presence of multiple transcripts of varying size for SN1. When expressed in mammalian cells, the cloned human SN2 mediates Na(+)-coupled transport of system N-specific amino acid substrates (glutamine, asparagine, and histidine). In addition, SN2 also transports serine, alanine, and glycine. Anionic amino acids, cationic amino acids, imino acids, and N-alkylated amino acids are not recognized as substrates by human SN2. The SN2-mediated transport process is Li(+)-tolerant and highly pH-dependent. The Michaelis-Menten constant for histidine uptake via human SN2 is 0.6 +/- 0.1 mM. The gene coding for SN2 is located on human chromosome Xp11.23. Successful cloning of SN2 provides the first molecular evidence for the existence of subtypes within the amino acid transport system N in mammalian tissues.

Structure and function of ATA3, a new subtype of amino acid transport system A, primarily expressed in the liver and skeletal muscle.

To date, two different transporters that are capable of transporting alpha-(methylamino)isobutyric acid, the specific substrate for amino acid transport system A, have been cloned. These two transporters are known as ATA1 and ATA2. We have cloned a third transporter that is able to transport the system A-specific substrate. This new transporter, cloned from rat skeletal muscle and designated rATA3, consists of 547 amino acids and has a high degree of homology to rat ATA1 (47% identity) and rat ATA2 (57% identity). rATA3 mRNA is present only in the liver and skeletal muscle. When expressed in Xenopus laevis oocytes, rATA3 mediates the transport of alpha-[(14)C](methylamino)isobutyric acid and [(3)H]alanine. With the two-microelectrode voltage clamp technique, we have shown that exposure of rATA3-expressing oocytes to neutral, short-chain aliphatic amino acids induces inward currents. The amino acid-induced current is Na(+)-dependent and pH-dependent. Analysis of the currents with alanine as the substrate has shown that the K(0. 5) for alanine (i.e., concentration of the amino acid yielding half-maximal current) is 4.2+/-0.1 mM and that the Na(+):alanine stoichiometry is 1:1.

Glutamine and the gastrointestinal tract.

The amino acid glutamine has become one of the most intensively studied nutrients in the field of nutrition and metabolic support. A variety of studies in cell culture systems, animal models of gut mucosal atrophy, injury/repair and adaptation and a limited number of clinical trials demonstrate trophic and cytoprotective effects of glutamine in small bowel and colonic mucosal cells. Although the routine clinical use of glutamine-enriched parenteral and enteral nutrient solutions remains controversial, available data demonstrate both the safety and metabolic and clinical efficacy of glutamine treatment in selected patient groups. Basic investigations are elucidating underlying mechanisms of glutamine action in intestinal cells. These will inform preclinical and clinical investigations designed to determine glutamine efficacy in selected gastrointestinal disorders. Emerging clinical trials will further define the utility of adjunctive glutamine supplementation as a component of specialized nutrition support in gastrointestinal disease.

Timing of percutaneous endoscopic gastrostomy tube placement in head and neck cancer patients.

Percutaneous endoscopic gastrostomy (PEG) is an effective method for providing alimentation in patients with upper aerodigestive tract carcinoma. Multiple complications of this procedure have been reported, ranging from leakage around the tube to tumor seeding of the abdominal cavity. This study was undertaken to determine whether the timing of PEG tube placement with respect to primary tumor extirpation led to a difference in the number and severity of observed complications. The medical records of 43 patients with head and neck carcinoma who had PEG tubes placed from 1995 to 1996 were retrospectively reviewed. Comparisons of timing of PEG tube placement, complication, location, and stage of the primary tumor were performed. In addition, the use of adjuvant therapy with respect to the time of PEG tube placement and complications was evaluated. Of these, 23% were done before and 30% during surgery at the time of primary tumor resection (9 of 13 were after primary removal). One patient had an intraabdominal abscess. Minor complications occurred in 15 of 43 patients (35%) and included granulation tissue at the PEG site, leakage, and tube displacement. Eight of the 9 patients who underwent intraoperative PEG after tumor resection had no complications. Patients who underwent PEG during or after surgery had significantly fewer complications than those who underwent preoperative PEG or had unresectable tumors (P = 0.038). The largest number of complications occurred in patients who underwent preoperative PEG (57%) followed by patients whose tumors were unresectable (31%). There was no statistical difference with regard to tumor location or postoperative x-ray therapy in PEG complications. This study demonstrates that PEG tube placement after tumor resection has the lowest incidence of postoperative complications. Performing PEGs intraoperatively after tumor resection can prevent the need for additional anesthesia to provide alimentation in patients with upper aerodigestive tract carcinoma.

Infection in surgical patients: effects on mortality, hospitalization, and postdischarge care.

In-hospital mortality, length of stay (LOS), and level of postdischarge care in infected and noninfected surgical patients were studied. An analysis was conducted of a database that included diagnostic, procedure, and drug data collected when surgical patients were discharged from the hospital. Hospitals consisted of 90 nongovernment, nonspecialty, teaching, and nonteaching acute care hospitals of more than 100 beds. Patients in the database included 288,906 patients of all ages hospitalized between July and September 1994. Patients selected of those who had undergone procedures likely to pose a moderate to high risk of infection. Of the 288,906 patients, 12,384 had undergone a moderate- to high-risk procedure; of these, 1,479 (11.9%) had had an infection during their hospitalization. Infection rates ranged from 1.9% to 25.4%, depending on the procedure. The in-hospital mortality rate in infected patients was 14.5%, versus 1.8% for noninfected patients. Similarly, LOS in infected patients (median, 14 days) was substantially greater than in noninfected patients (4 days). About 24% of infected patients required additional professional care after discharge, compared with 7% of noninfected patients. Infection occurs in a substantial portion of surgical patients and is associated with a higher death rate, longer hospitalization, and more intense postdischarge care.

The adverse effects of octreotide on wound healing in rats.

Octreotide acetate is a long-acting somatostatin analogue with protean physiologic effects. It is used primarily as an inhibitory paracrine hormone to treat a variety of medical and surgical disorders, including endocrine tumors and several gastrointestinal hypersecretory states. Because of octreotide's known inhibition of multiple trophic and anabolic hormones, we suspected that it may have deleterious effects on wound healing. Twenty-four rats were randomized to one of three groups: control, steroid (a negative control), or octreotide. Dorsal midline incisions were made and closed primarily. Wound-breaking strength measurements were performed 7 days later. The mean peak load (+/- standard error of the mean) for each group was calculated: control = 754 +/- 89 g; steroid = 378 +/- 32 g; and octreotide = 427 +/- 41 g. The difference between the control group and each of the other groups was statistically significant with P < 0.030. We conclude that octreotide has significant adverse effects on wound healing in the rat model and that these effects are comparable in magnitude to those caused by steroids.

The effects of octreotide on healing of small bowel anastomosis.

Octreotide (OCT) is a somatostatin analog used for its inhibitory action on multiple GI functions. Although octreotide has numerous clinical benefits, it has also been shown to inhibit postresectional hyperplasia of small bowel and hepatic regeneration. Because octreotide inhibits both trophic and anabolic hormones, we hypothesize that the use of octreotide may be detrimental in patients with a recent bowel anastomosis. To test this hypothesis, 60 male rats were randomized to four equal groups following small bowel anastomosis. Group I = control; Group II = 10 mg/day of hydrocortisone succinate; Group III = 2.5 micrograms/kg/day octreotide (equivalent of a clinical dose); Group IV = 25 micrograms/kg/day octreotide. Hydrocortisone was used as a negative control because it is known to have inhibitory effects on small bowel anastomotic healing. On postoperative Day 7, bursting pressures were measured. Serum T-kininogen levels, as a marker for systemic inflammation, and hydroxyproline content from the anastomotic segments were obtained. These results indicate that in the rat small bowel model, octreotide did not have any deleterious effect on anastomotic strength, systemic inflammation, and collagen content, even at high doses. Hydrocortisone, as expected, showed significant detrimental effects on bursting strength, as well as decreasing systemic inflammation. These findings have significant clinical implications, as octreotide could be used without jeopardizing the intestinal anastomosis.

The clear liquid diet is no longer a necessity in the routine postoperative management of surgical patients.

The reinstitution of oral intake in patients who have undergone intra-abdominal surgery has traditionally progressed in a stepwise fashion. Various retrospective studies and anecdotal reports have suggested that a "regular" diet as the first postoperative meal is well tolerated. Although clear liquids are accepted as the standard first postoperative meal, there appears to be little scientific data to support their use. The current study was undertaken to determine whether there is any difference in tolerance to clear liquids versus a regular diet as the first postoperative oral intake. This study is not intended to suggest that clear liquid diets harm patients but to attempt to support our hypothesis that a regular diet as the first postoperative meal is not associated with and increased morbidity. A total of 241 patients undergoing abdominal operations were prospectively randomized to receive either routine clear liquids (N=135) or regular diet (N=106) as the first oral intake. They were followed for any symptoms or signs of dietary intolerance. The group receiving a regular diet was not found to have any statistically significant increase in dietary intolerance in comparison with the clear liquid group. Nutritional data collected in a subset of patients revealed a higher caloric intake in those assigned to a regular diet. These results suggest that the routine use of clear liquids as the initial postoperative diet may be unnecessary and nutritionally suboptimal when compared with a regular diet.

Laparoscopic gastrostomy using four-point fixation.

Percutaneous endoscopic gastrostomy (PEG) has become an effective alternative to surgical gastrostomy in patients who require enteral access or gastric decompression. Technical considerations, however, limit the application of PEG in selected patients and those who have contraindications to PEG. Laparoscopic gastrostomy tube placement has been introduced as an alternative to PEG. A technique for laparoscopic gastrostomy tube placement that emphasizes four-point fixation of the anterior gastric wall is presented.