Infrainguinal vein graft surveillance: the criteria for intervention.

In most patients, infrainguinal vein grafts are commonly performed for limb-threatening ischemia. Once limb salvage has been achieved, most clinicians agree that regular appointments with the vascular team are important to monitor graft patency. However, the timing of these appointments and what defines an adequate examination remains debatable. The following cases illustrate the natural history and interventions performed in 2 such patients. A review of the literature and a commentary on surveillance strategies is provided to elucidate the advantages and disadvantages of currently available vascular laboratory testing. Recommendations also are made for the appropriate timing of intervention to revise these grafts.

Current status of the surgical treatment of patients with carotid artery disease: the surgical management of carotid atherosclerosis.

Patients with carotid artherosclerotic disease present with a history of a neurologic event or with the presence of a bruit on physical examination. Recently, large randomized prospective studies have examined this group of patients to determine the optimal course of medical and surgical management. The data from these studies, together with the natural history of carotid disease and factors associated with stroke risk, are reviewed.

Prospective comparison of helium versus carbon dioxide pneumoperitoneum.

BACKGROUND: During prolonged laparoscopic operations with carbon dioxide (CO2) pneumoperitoneum (PP), hypercapnia with significant acidosis has been reported to occur in some patients with pulmonary dysfunction. An alternate inert insufflation gas like helium (He) could avoid this problem. METHODS: This prospective, IRB-approved study compared the cardiopulmonary response in 20 patients with both CO2 and He PP. With the minute ventilation held constant, baseline arterial blood gases and ventilatory and cardiac parameters were obtained after anesthetic induction but prior to CO2 PP. All values were repeated at 20 to 30 and 40 to 60-minute intervals after the insufflation of CO2 PP, then again during He PP. Values were compared by a paired t test analysis. RESULTS: Patients experienced significant hypercapnia during CO2 PP when compared with baseline arterial blood gases, but all values returned to baseline levels during He PP. CONCLUSIONS: He PP is an effective alternative to CO2 PP for a laparoscopic cholecystectomy avoiding CO2 retention and subsequent acidosis. Carbon dioxide retention may be dangerous in patients with pulmonary dysfunction who undergo laparoscopy.

Hyperbilirubinemia without common bile duct abnormalities and hyperamylasemia without pancreatitis in patients with gallbladder disease.

OBJECTIVE: To determine the incidence of jaundice and hyperamylasemia in the absence of common bile duct abnormalities or clinical pancreatitis in patients undergoing cholecystectomy. DESIGN: A continuous, prospective analysis of a consecutive case series was performed on all patients undergoing cholecystectomy. SETTING: An urban, tertiary care university hospital. PATIENTS: Adult patients with gallbladder disease. INTERVENTION: All patients underwent cholecystectomy. MAIN OUTCOME MEASURES: The presence or absence of common bile duct abnormalities was evaluated by cholangiography, and pancreatitis was identified by clinical signs, imaging studies, and direct visual inspection during cholecystectomy. RESULTS: All patients (N = 1746) undergoing cholecystectomy were prospectively categorized as having chronic calculous (n = 1410), acute calculous (n = 217), chronic acalculous (n = 70), or acute acalculous (n = 49) gallbladder disease. It was uncommon for patients with chronic calculous cholecystitis to have an elevated bilirubin level with no choledocholithiasis and a normal common bile duct or to have hyperamylasemia without pancreatitis. Twenty-five percent of the patients with acute calculous cholecystitis had a serum bilirubin level between 34 and 86 mumol/L (2.0 and 5.0 mg/dL) with no common bile duct abnormality and 4% had hyperamylasemia without pancreatitis. Over one third of the patients with acute acalculous cholecystitis had an elevated bilirubin level with a normal common bile duct or an elevated amylase level without pancreatitis. CONCLUSION: Jaundice and hyperamylasemia can be produced by gallbladder disease alone.

Evaluation of alternative proximal gastric vagotomy techniques after a 9-month interval in a rat model.

Proximal gastric vagotomy (PGV) is an accepted operation for patients with ulcers that are refractory to medical management. Results comparable to those of standard, operative PGV have previously been demonstrated using endoscopic chemoneurolytic injection or laparoscopic laser seromyotomy in a porcine model. In this study, we evaluated several PGV techniques in regard to long-term effects on acid secretion, ulcer prophylaxis, and permanent vagal denervation in a rat model. Trans-mucosal injection of chemoneurolytic agents (cobaltous chloride, benzalkonium chloride, and phenol) and seromyotomy by CO2 laser were performed. After 9 months, all rats received sub-serosal gastric injections of horseradish peroxidase (HRP) during laparotomy. Twenty-four hours later, an ulcerogenic dose of pentagastrin was administered sub-cutaneously. Three days after administration of HRP (to allow time for retrograde axonal transport and labeling of cells of the dorsal vagal nucleus with HRP), necropsy was performed. The pre-pyloric gastric mucosa was inspected for ulcerogenic changes, and a Congo red solution was applied to the gastric mucosa to map the acid-secreting areas. All PGV methods significantly diminished pentagastrin-induced ulceration when compared to sham controls. Benzalkonium chloride chemoneurolytic and laser methods were most effective for decreasing the size of acid-secreting areas. A reduced number of HRP-stained cells in the dorsal vagal nucleus indicated permanent denervation of vagal-gastric connections by operative and laser techniques.

Cholecystectomy. Which procedure is best for the high-risk patient?

Laparoscopic cholecystectomy (LC), which results in less postoperative pain, disability, and scarring, has become an attractive alternative method of surgical management of the ambulatory patient with gallbladder disease. The best procedure for severely ill patients who are poor operative risks but require cholecystectomy, however, is unknown since the operative morbidity and mortality of LC in this group of patients had not been studied. All patients (177) undergoing cholecystectomy at one institution were evaluated. Based on their preoperative state of health as defined by a modified acute physiologic score (APS), patients were divided into two groups; one group was defined by an APS of less than 10, indicating they were in good health, and the other had an APS greater than or equal to 10, indicating that the group had multiple risk factors, predicting an increased postoperative morbidity and mortality. Selection for either procedure, LC or open cholecystectomy (OC), was made independently of the patient's preoperative status. Patients' past medical histories; demographic, physiologic, and laboratory data; and postoperative complications were evaluated. When all cholecystectomy patients were arranged into the respective risk groups, the age and severity of illness scores (APS) between LC and OC were not statistically different. Intraoperative and postoperative complications were not significantly different when patients undergoing LC were compared to patients undergoing OC. Laparoscopic cholecystectomy was associated with decreased hospitalization when compared to patients undergoing OC. The overall mortality of the patients undergoing OC was significantly greater than those undergoing LC. LC is an acceptable surgical alternative for high-risk patients requiring cholecystectomy.

Preoperative pulmonary function evaluation for laparoscopic cholecystectomy.

OBJECTIVE: Hypercarbia with respiratory acidosis is a recognized complication of laparoscopic cholecystectomy. This study was performed to identify preoperatively those patients who may develop hypercarbia and acidosis during the procedure. DESIGN: Retrospective analysis of preoperative variables. PATIENTS: Thirty-one consecutive patients underwent laparoscopic cholecystectomy at one institution who were receiving both preoperative pulmonary function tests and arterial blood gas analysis. RESULTS: More than 80 demographic, laboratory, and perioperative variables were entered into a univariate analysis to identify predictors of intraoperative acidosis (pH, < 7.35). Patient age, duration of the procedure, and preoperative blood gas values were not predictors of intraoperative acidosis. Several univariant predictors for patients experiencing carbon dioxide pneumoperitoneum-induced hypercarbia were identified; these included an elevated American Society of Anesthesiologists classification and significant decreases in forced expiratory flow at 25% of maximum, maximal forced expiratory flow, maximal voluntary ventilation, vital capacity, inspiratory capacity, and diffusing capacity of the lung for carbon monoxide. CONCLUSIONS: This study suggests that neither age nor preoperative arterial blood gas values are predictive of intraoperative hypercarbia and acidosis during periods of carbon dioxide pneumoperitoneum. However, preoperative pulmonary function measures of decreased flow, limited capacity, and compromised diffusion do correspond to the development of intraoperative acidosis. Preoperative evaluation with pulmonary function tests demonstrating forced expiratory volumes less than 70% of predicted values and diffusion defects less than 80% of predicted values can identify those patients who are at risk of developing hypercarbia and acidosis.

Proximal gastric vagotomy by minimally invasive methods in an acute rat model.

In this prospective study, minimally invasive methods of proximal gastric vagotomy (PGV) were investigated in male Sprague-Dawley rats. Completeness of vagotomy by traditional operative therapy, by laser denervation of the gastric serosa, and by subserosal or transmucosal injections of chemoneurolytic agents was evaluated with postoperative Congo red testing, ulcerogenic stimulation of the gastric mucosa, and histochemical labeling of whatever vagal fibers remained in the gastric wall. Short-term results demonstrate that successful PGV can be performed with minimally invasive methods.

Comparison of minimally invasive methods of parietal cell vagotomy in a porcine model.

BACKGROUND: Parietal cell vagotomy (PCV) is an accepted therapy for peptic ulcer disease. Traditional operative PCV results may be obtained laparoscopically or endoscopically. The purpose of this study was to quantitatively evaluate newer methods of PCV. METHODS: Variations in PCV, gastroscopic chemoneurolysis and laparoscopic photoneurolysis, were evaluated in 20 to 25 kg pigs. Traditional operative PCV was performed by laparotomy and served as the operative control. With a posterior truncal vagotomy, a PCV was performed laparoscopically by an anterior seromyotomy with either operative division of the neurovascular bundles with titanium clips or with a defocused CO2 laser. Transesophageal gastroscopic PCV was performed by transmucosal injections of the chemoneurolytic agents, 0.75% cobaltous chloride or 0.1% benzalkonium chloride. Adequacy of PCV at the time of operation was assessed by endoscopic Congo red testing. Two weeks later, repeat Congo red testing was performed by open gastrotomy. Quantitation of completeness of PCV and statistical comparison was determined by photographing the pentagastrin-stimulated gastric mucosa 5 minutes after Congo red application and subsequent comparison of innervated area versus total gastric mucosal area by a computer-driven digitized area-calculation program. RESULTS: All PCV techniques studied produced significant acid-secretory reduction, and both laparoscopic and gastroscopic PCV denervated the parietal cells in a manner comparable with operative PCV. Laser photoneurolysis could only be accomplished by producing full-thickness necrosis of the gastric wall. Submucosal injection of cobaltous chloride produced granulomatous nodules with foreign body crystals. Unlike operative and laparoscopic PCV, transmucosal gastroscopic benzalkonium PCV did not produce gross gastroparesis. CONCLUSIONS: All evaluated laparoscopic and endoscopic PCV techniques effectively denervated the parietal cells of the porcine stomach when evaluated at 2 weeks after treatment. Gastroscopic submucosal injection of benzalkonium chloride produced effective denervation with no evident histologic tissue changes and suggestive evidence of normal gastric emptying. Further evaluation with more extended periods of observation of these new techniques of performing PCV appear warranted.

Analysis of the hemodynamic and ventilatory effects of laparoscopic cholecystectomy.

Laparoscopic cholecystectomy uses carbon dioxide, a highly diffusable gas, for insufflation. With extended periods of insufflation, patient arterial carbon dioxide levels may be adversely altered. Patients were selected for laparoscopic cholecystectomy using the same criteria as for open cholecystectomy. Twenty patients (group 1) had normal preoperative cardiopulmonary status (American Society of Anesthesiologists class I), while 10 patients (group 2) had previously diagnosed cardiac or pulmonary disease (class II or III). Demographic, hemodynamic, arterial blood gas, and ventilatory data were collected before peritoneal insufflation and at intervals during surgery. Patients with preoperative cardiopulmonary disease demonstrated significant increases in arterial carbon dioxide levels and decreases in pH during carbon dioxide insufflation compared with patients without underlying disease. Results of concurrent noninvasive methods of assessing changes in partial arterial pressures of carbon dioxide (end-tidal carbon dioxide measured with mass spectrographic techniques) may be misleading and misinterpreted because changes in partial arterial pressures of carbon dioxide are typically much smaller than changes in arterial blood levels and, unlike arterial gas measurements, do not indicate the true level of arterial hypercarbia. During laparoscopic cholecystectomy, patients with chronic cardiopulmonary disease may require careful intraoperative arterial blood gas monitoring of absorbed carbon dioxide.

Cystic duct cholangiography during laparoscopic cholecystectomy.

At present, there is no consensus regarding the routine use of intraoperative cholangiography during cholecystectomy. We describe a reliable technique for performing cystic duct cholangiography during laparoscopic cholecystectomy. Using this technique, we were able to cannulate the cystic duct in 97% of patients, completely visualize the biliary tree and duodenum in 93% of patients, and identify unsuspected choledocholithiasis in 3% of patients. Treatment options for the management of choledocholithiasis demonstrated by cholangiograms during laparoscopic cholecystectomy include conversion to an open cholecystectomy and common duct exploration, or endoscopic sphincterotomy and common duct stone extraction following laparoscopic cholecystectomy.