Do laparoscopic colectomy techniques compromise oncologic principles?

BACKGROUND: Benefits of laparoscopic techniques over traditional open techniques in colon surgery are well recognized. Although both hand-assisted laparoscopic colectomy (HALC) and laparoscopic-assisted colectomy (LAC) can beeffective in the treatment of colon cancer, the superiority of either technique has yet to be determined for oncologic procedures. MATERIALS AND METHODS: A five-year retrospective study comparing outcomes of hand-assisted laparoscopic and laparoscopic-assisted colectomies for cancer was conducted at our community-based teaching hospital. Demographic data, tumor location and stage of the disease were analyzed. Outcomes compared between the two procedures included number of lymph nodes retrieved, presence of positive margins, operative time, length of stay, and number of early postoperative complications. RESULTS: Fifty patients underwent HALC, while 23 underwent LAC during the study period. Demographic data were similar between the two groups. Operative time was longer for LAC, compared with HALC (178 vs. 125 min., p < 0.05), however, the average number of lymph nodes retrieved was significantly higher in LAC compared with HALC (14 vs. 10, p < 0.05). No significant differences were recorded for positive margins, postoperative complications, or the length of hospital stay. CONCLUSIONS: While HALC was more prevalent at our institution and proved to be associated with decreased operative times, the number of lymph nodes retrieved was sub-optimal and compared less favorably with LAC. Above all, oncologic principles should be respected and achieved regardless of the operative technique used.

Parenteral nutrition techniques in cancer patients.

If a patient is expected to respond optimally to one or more forms of oncologic therapy, he should simultaneously be in the best possible nutritional and metabolic condition. When the alimentary tract cannot be used effectively for feeding cancer patients, parenteral nutrition can be lifesaving. Moreover, patients who are poor candidates or noncandidates for any antineoplastic therapy because of their debility or cachexia can be converted to reasonable candidates following a course of i.v. hyperalimentation. This i.v. hyperalimentation can significantly reduce the morbidity and mortality of cancer patients without stimulating tumor growth when applied conscientiously according to the established principles and techniques and when integrated with specific tumor therapy. With the use of ambulatory or home hyperalimentation techniques, normal nutritional status can be restored or maintained during prolonged periods of antineoplastic therapy on a practical and relatively economical outpatient basis. It is anticipated that specific nutrient substrate formulas and parenteral therapy techniques will be developed to maintain optimal host nutrition while adversely affecting the neoplasm.

Renal failure in surgical patients. Treatment with intravenous essential amino acids and hypertonic glucose.

Solutions containing balanced quantities of essential L-amino acids, hypertonic glucose, and other essential nutrients were administered by vein to ten patients who had acute or chronic renal failure associated with or resulting from catastrophic complications precluding use of the gastrointestinal tract for alimentation. Weight gain, wound healing, and positive nitrogen balance occurred uniformly during periods of total intravenous nutrition, while blood urea nitrogen remained stable or decreased and the signs and symptoms of azotemia resolved. Restoration of nutritional balance and achievement of protein synthesis is possible in patients who have renal failure and gastrointestinal dysfunction by the judicious administration of high biologic value diets exclusively by vein.

Effects of intravenous nutrition on tumor growth and host immunocompetence in malnourished animals.

To evaluate the effects of oral and intravenous nutritional repletion on tumor growth and host immunocompetence in malnourished animals, 60 adult purified protein derivative (PPD) positive Buffalo rats were inoculated with Morris hepatoma 5123 and were fed a regular diet for 14 days. All animals then were switched to a high carbohydrate, protein-free diet for the next 14 days, at which time only 30% of the animals remained PPD positive. Rats then were divided into three groups: group I underwent superior vena cava catheterization and received a constant infusion of 25% dextrose--4.25% amino acid solution; group II was switched to the regular protein diet orally ad libitum; and group III remained on the oral protein-free diet. PPD reactivities were measured prior to death 7 days later. Group I animals gained an average of 14 gm of body weight, and 91% of the animals were PPD positive. Group II animals lost an average of 17 gm of body weight, but 78% of the animals were PPD positive. Group III animals lost an average of 23 gm of body weight, and only 12% of the animals remained PPD positive. Absolute tumor weight and tumor weight: body weight ratios were not significantly different among the three groups of animals. Provision of adequate nutrition intravenously to malnourished tumor-bearing animals restores body weight and host immunocompetence without adversely stimulating tumor growth out of proportion to growth of the host.

Homocysteine stimulates MAP kinase in bovine aortic smooth muscle cells.

BACKGROUND: Hyperhomocysteinemia is recognized as a risk factor for atherosclerotic disease. However, the mechanism of homocysteine effects on smooth muscle cell proliferation, which is a hallmark of atherosclerosis, is unknown. The object of this study was to test the effects of homocysteine on smooth muscle cell proliferation, and to examine the mitogen-activated protein (MAP) kinases, extracellular signal-regulated protein kinase 1 and 2, that are known to be involved in cell proliferation. METHODS: For the proliferation study, bovine aortic smooth muscle cells (BASMC, 10, 000/well) were allowed to grow for 2 days before 2 mmol/L D,L -homocysteine was added for 2, 4, 6, and 8 days to simulate the clinical hyperhomocysteinemic condition. For the MAP kinase study, quiescent BASMC were exposed to 2 mmol/L D,L -homocysteine for 1.5, 5, 10, 20, 30, and 60 minutes, and the active forms of MAP kinase were detected with Western immunoblotting. The degree of phosphorylation of MAP kinase was determined by densitometry. RESULTS: D,L -homocysteine stimulated BASMC proliferation by 20% by day 8. MAP kinase phosphorylation was activated as much as six fold by D,L -homocysteine, with a peak at 30 minutes. PD98059, an inhibitor of MAP kinase phosphorylation, inhibited the homocysteine-induced MAP kinase phosphorylation and attenuated the increase in BASMC proliferation. CONCLUSIONS: These data are consistent with the hypothesis that D,L -homocysteine stimulation of BASMC proliferation involves MAP kinase activation.

Adaptation to amino acid infusion in patients undergoing operation.

Urine ketone levels were measured in patients receiving peripheral amino acid solutions, and the results were correlated with changes in nitrogen balance. Thirty well-nourished patients who were to undergo cystectomy were placed on liquid, noncarbohydrate diets 3 days before operation, and no oral intake was allowed until 7 days after operation. Crystalline amino acid (1.3 to 1.5 gm/kg/day) solutions were infused continuously from 3 days before to 7 days after operation. Blood was obtained 3 days before and 3, 7, and 10 days after operation; 24-hour urine outputs were determined daily. Qualitative urine acetone levels were determined four times daily. During the infusion period, 14 (47%) patients developed ketonuria (group I); 16 patients did not (group II). The mean serum glucose levels ranged from 99 to 107 mg/dl in group I and from 108 to 113 mg/dl in group II (P less than 0.05). The mean serum transferrin level decreased after operation to 117 mg/dl in group I and 97 mg/dl in group II. The mean cumulative adjusted nitrogen balance was -24 +/- 8 gm in group I and -47 +/- 9 gm in group II (P less than 0.05). No patient developed sepsis. Qualitative testing of urinary ketones correlated with significant alterations in blood urea nitrogen, serum glucose, transferrin, and cumulative adjusted nitrogen balance. The bedside determination of urinary ketones may be useful in assessing a patient's adaptation to peripheral amino acid infusions.

Postsplenectomy Capnocytophaga canimorsus sepsis presenting as an acute abdomen.

Patients with intra-abdominal processes that require prompt surgical intervention, including appendicitis, perforated viscus, ischemic bowel, volvulus, and bowel obstruction, often present with signs and symptoms of an acute abdomen. Several medical problems can mimic an acute abdomen. Overwhelming postsplenectomy infection is a life-threatening condition that can present with acute abdominal symptoms. The incidence of overwhelming postsplenectomy infection ranges from 1% to 25%, and is caused by Streptococcus pneumoniae in 50% of cases. Capnocytophaga canimorsus, a bacteria commonly found in dog saliva, accounts for less than 1% of cases. Overwhelming postsplenectomy infection has a rapidly deteriorating course that progresses to respiratory and renal failure, cardiovascular collapse, and death. The mortality associated with overwhelming postsplenectomy infection is 60% to 80%. Early diagnosis and institution of appropriate antibiotic therapy and supportive care is essential to improve patient outcome. A previously healthy woman who had undergone splenectomy secondary to trauma 11 years earlier presented with symptoms of an acute abdomen. A diagnosis of overwhelming postsplenectomy infection due to C canimorsus was made based on her peripheral blood smear and blood culture findings. Early aggressive care and antibiotic treatment resulted in a successful outcome for this patient with no long-term morbidity. This patient's clinical course demonstrates the importance of early diagnosis and treatment of overwhelming postsplenectomy infection.

Rapid restoration of red blood cell mass in severely anemic surgical patients who refuse transfusion.

Optimal parenteral nutritional support, concomitant with replacement doses of intravenous iron dextran injection, can be safe, effective, and lifesaving for severely anemic patients who are unable to receive blood transfusions. Six patients who had sustained massive acute blood loss and two who had severe chronic anemia received as much as 140 mL of iron dextran injection intravenously. The average initial hemoglobin level in the acute group was 5.0 g/dL (range, 2.6 to 8.4 g/dL) and increased to an average of 10.6 g/dL (range, 7.5 to 12.8 g/dL) in 23 days (range, 17 to 30 days); the hemoglobin level in the chronic group was 3.8 g/dL and increased to 10.6 g/dL over an average period of 121 days. Two total abdominal colectomies, a right transverse colectomy and fistulectomy, a pyloroplasty and vagotomy, and a highly selective vagotomy were accomplished without complications in five of the patients. There were no adverse reactions to the hematopoietic therapy.

Enteral and parenteral feeding to evaluate malabsorption in intestinal parasitism.

General evidence of malnutrition such as loss in body weight associated with intestinal parasitism has been attributed to decreased food intake, to intestinal malabsorption, and to change in host basal metabolism. To establish the relative importance of these factors in this regard, rats with trichinosis were studied. The weights of infected and uninfected animals were followed after being placed on one of three feeding regimens for 1 week--stock diet ad libitum, intraduodenal nutrition, and intravenous nutrition. Infected rats on a stock diet lost weight whereas those on the other two regimens maintained the same weight pattern as uninfected counterparts. The maintainance of body weight occurred despite alterations at the level of the intestinal brush border as indicated by a depression of intestinal disaccharidase activities (sucrase and lactase) and by reduction of monosaccharide absorption (measured as accumulation of beta-methyl glucoside) in the proximal, heavily infected region of the small intestine. There was no compensatory increase in enzyme activity nor in the absorptive capacity in the distal gut. Results support the conclusion that inadequate oral food intake rather than changes in basal metabolism or intestinal pathophysiology accounts for weight loss during the intestinal phase of infection.

Serum and antral gastrin levels in rats infected with intestinal parasites.

Serum and antral gastrin were measured in rats infected with either Trichinella spiralis or Hymenolepis diminuta as a step in testing the hypothesis that parasites change certain aspects of host physiology by altering gastrointestinal (GI) hormone levels or responses to GI hormones. Parasitism with T. spiralis was associated with inflammatory changes in the small bowel mucosa and with a significant increase in serum gastrin. Neither changes in hormone level nor inflammation were induced in tapeworm-infected rats. These results reveal the capacity of tissue penetrating parasites to alter the level of circulating gastrin. This finding coupled with considerable indirect evidence suggests that some of the pathologic changes induced in hosts by enteric parasites may be due to changes in functions that are regulated by GI hormones.

Nutritional concepts in the treatment of head and neck malignancies.

Cancer cachexia should no longer be a contraindication to adequate antineoplastic treatment. Current methods of nutritional assessment allow one to identify malnutrition and to follow the nutritional status of the patient throughout the cancer-management program. Enteral nutritional repletion and maintenance remain the ideal course of action, but the gastrointestinal tract is not always readily available or advisable for use; in such circumstances, intravenous hyperalimentation (IVH) may be indicated. The properly nourished patient better tolerates cancer therapy, experiences fewer complications of malnutrition (e.g., sepsis and poor wound healing), and has a better-functioning immune system than does his malnourished counterpart. This article reviews methods of nutritional assessment, delineates indications and techniques for nutritional repletion, and summarizes the results obtained.

Routine chest radiographs following central venous recatheterization over a wire are not justified.

BACKGROUND: Subclavian vein central venous catheterization and the subsequent exchange of subclavian catheters over a guidewire are frequently performed procedures. We hypothesized that the policy of obtaining a routine postprocedure chest radiograph to confirm appropriate catheter placement and to rule out complications after exchanging central venous catheters over a wire was no longer justifiable. METHODS: A retrospective study of 295 patients with Swan-Ganz catheters (SGC) was performed between July 1, 1994 and June 30, 1996. One hundred fourteen of these SGCs were exchanged over a guidewire for a central venous catheter (CVC). Postexchange chest radiograph and associated radiologist's report, as well as age, gender, and duration of catheter placement were all recorded. Since July 1996, this study has been extended prospectively. RESULTS: Of the 380 documented over-a-wire exchanges, none has resulted in a complication, including catheter malposition. CONCLUSION: We conclude from these data that a routine chest radiograph following the replacement of a CVC over a guidewire is not necessary when good clinical judgment and discrimination are used in a monitored setting.

The efficacy of X-rays after chest tube removal.

BACKGROUND: The insertion and subsequent removal of chest tubes are frequently performed procedures. We hypothesize that routine chest radiographs obtained after chest tube removal to confirm the absence of any post-procedure complications have little impact on clinical management. MATERIALS AND METHODS: A 5-year retrospective study of 73 patients with tube thoracotomies was performed in a level II trauma center's intensive care unit. Patients were identified from billing records for chest tube placement. Medical records and official chest x-ray film reports, both before and after removal, were reviewed, and demographic data were collected. RESULTS: Of the 73 patients examined, only 8 had postprocedure reports that differed from the preprocedure reports. Two of these 8 patients required reinsertion of a chest tube to treat the recurrence of a significant pneumothorax. However, the decision to reinsert the chest tube was based on the patient's clinical appearance rather than on the x-ray findings. CONCLUSION: Chest radiography following the removal of chest tubes should not be a routinely performed procedure, but should preferably be based on the good clinical judgement and discrimination of the surgeon.

Intravenous hyperalimentation as an adjunct to cancer chemotherapy.

A 36 per cent response rate was obtained in fifty-eight nutritionally depleted patients with cancer who would otherwise have been denied adequate antitumor therapy because of the fear of complications from malnutrition and inanition. A positive correlation between the nutritional status of the patient and the chemotherapeutic tumor response was identified. Intravenous hyperalimentation can be a valuable adjunct to cancer chemotherapy by improving the nutritional status, increasing the total deliverable dose of anticancer agent per unit of time, and reducing the incidence and severity of the toxic gastrointestinal side effects without adversely stimulating malignant cell growth or producing septic complications.

Implementation of a multidisciplinary nutritional assessment program.

Depending on the severity of malnutrition, protein depletion is associated with general debilitation, inanition, slow healing of wounds, delayed convalescence, increased susceptibility to infection, and other pathophysiologic conditions. In an effort to decrease the incidence and severity of these complications, Hermann Hospital and the University of Texas Medical School at Houston have implemented a comprehensive nutritional assessment program to identify clinical and subclinical malnutrition and to implement aggressive, effective therapy. A multidisciplinary team approach to nutritional assessment, therapy, and research can lead to an increased awareness of the importance of nutritional support and optimal nutritional care for the hospitalized patient under all conditions at all times.

Delayed hypersensitivity skin testing: response rates in a surgical population.

The results of this study indicate that skin test responses should be measured at both 24 and 48 hours post-injection and considered reactive or positive if induration of greater than or equal to 5 mm. is noted at either time. The practice of measuring responses at 48 hours only is neither appropriate nor recommended as it may produce a large percentage of false negative results. Erythema without induration was noted in a small percentage of patients. Future studies should evaluate the efficacy of erythema greater than or equal to 15 mm. in the absence of induration as a reactive response to mumps antigen. The validity of data interpretation must ultimately be based on correlations with morbidity and mortality. Streptokinase-streptodornase, mumps, and trichophyton were the three antigens with highest response rates, and this battery detected 94% of the reactive or positive responses to the five-antigen battery.

Nutritional assessment indications of postburn complications.

This study evaluates the use of nutritional assessment indexes measured on the fifth day after injury to predict subsequent wound infections, episodes of septicemia, and other infectious complications in burned patients. Nutritional assessment data collected included anthropometric measurements (weight, height, triceps skinfold, and upper-arm circumference); biochemical testing (serum albumin concentration, serum transferrin concentration, total lymphocyte count, creatinine/height index, and nitrogen balance); and recall skin antigen testing. Seventy-four adult patients (mean age of 35 years) who had burn injuries ranging from 10% to 96% total body surface were studied. Indexes predictive of imminent wound infection include serum transferrin concentrations less than 150 mg/dl (p = .0006) and anergy to the skin test battery (p = .01). Those indexes were also prognostic of the development of septicemia (p = .0002 and p = .0001, respectively). Although statistically insignificant, total lymphocyte count also showed a similar trend toward predicting complications. Serum albumin concentration (less than 3.0 gm/dl), creatinine/height index (less than 60% standard), percent ideal body weight (less than 80%), percent weight change, and nitrogen balance did not contribute to group discrimination. Severe depletion of the visceral protein compartment was documented in a large percentage of patients on the fifth postburn day. Serum transferrin concentration and recall skin antigen testing can be helpful in identifying thermally injured patients who are at high risk of infectious complications.

Past, present, and future of nutritional support.

Early rudimentary attempts to provide adequate nutrition by mouth, intestinal tube, and vein in order to reduce morbidity and mortality have advanced to strategies designed to maintain the integrity of the body cell mass. Technology has progressed geometrically in recent years with the development of organ-specific enteral and parenteral substrate mixtures; sophisticated assessment, delivery, and monitoring systems; and improved safety and efficacy. Nutritional support is rapidly evolving into the practice of clinical biochemistry, in which nutrient substrates will be formulated to enhance or maximize cellular function, not only under normal conditions, but under a wide variety of pathophysiologic conditions.

Nutritional support in liver failure.

The most important manifestations of advanced liver disease are malnutrition, encephalopathy, and hepatorenal syndrome. Appropriate and optimal nutritional and metabolic support with specially formulated solutions enriched in branched-chain amino acids, together with other advanced treatments such as plasmapheresis, hemofiltration, and continuous arteriovenous hemodialysis, can correct the most important metabolic and clinical aberrations and temporarily improve the quality of life. However, the ultimately poor prognosis of patients with severe liver failure has not been altered significantly to date by the provision of nonspecific or specifically tailored nutrient regimens. The prognosis appears to depend on the arrest, correction, or reversal of the primary pathophysiologic process.

Nutritional management of acute and chronic pancreatitis.

Acute pancreatitis often results in a catabolic state characterized by profound hemodynamic, metabolic, cardiovascular, pulmonary, hematologic, and renal aberrations. Parenteral nutrition and metabolic support are essential if morbidity and mortality are to be minimized. In chronic pancreatitis, nutritional management ranges from fundamental dietary manipulation with or without administration of appropriate digestive enzymes to enteral supplementation with modular chemically defined diets to total parenteral nutrition, depending on the stage, severity, and manifestations of the disease. In prescribing nutrient substrates in both acute and chronic pancreatitis, consideration must be given to their effects on pancreatic enzyme secretion if optimal results are to be achieved.