Catherine M. Wittgen

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.

Treatment and outcomes of aortic endograft infection

OBJECTIVE This study examined the medical and surgical management and outcomes of patients with aortic endograft infection after abdominal endovascular aortic repair (EVAR) or thoracic endovascular aortic repair (TEVAR). METHODS Patients diagnosed with infected aortic endografts after EVAR/TEVAR between January 1, 2004, and January 1, 2014, were reviewed using a standardized, multi-institutional database. Demographic, comorbidity, medical management, surgical, and outcomes data were included. RESULTS An aortic endograft infection was diagnosed in 206 patients (EVAR, n = 180; TEVAR, n = 26) at a mean 22 months after implant. Clinical findings at presentation included pain (66%), fever/chills (66%), and aortic fistula (27%). Ultimately, 197 patients underwent surgical management after a mean of 153 days. In situ aortic replacement was performed in 186 patients (90%) using cryopreserved allograft in 54, neoaortoiliac system in 21, prosthetic in 111 (83% soaked in antibiotic), and 11 patients underwent axillary-(bi)femoral bypass. Graft cultures were primarily polymicrobial (35%) and gram-positive (22%). Mean hospital length of stay was 23 days, with perioperative 30-day morbidity of 35% and mortality of 11%. Of the nine patients managed only medically, four of five TEVAR patients died after mean of 56 days and two of four EVAR patients died; both deaths were graft-related (mean follow-up, 4 months). Nineteen replacement grafts were explanted after a mean of 540 days and were most commonly associated with prosthetic graft material not soaked in antibiotic and extra-anatomic bypass. Mean follow-up was 21 months, with life-table survival of 70%, 65%, 61%, 56%, and 51% at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Aortic endograft infection can be eradicated by excision and in situ or extra-anatomic replacement but is often associated with early postoperative morbidity and mortality and occasionally with a need for late removal for reinfection. Prosthetic graft replacement after explanation is associated with higher reinfection and graft-related complications and decreased survival compared with autogenous reconstruction.

Outcomes of Endovascular AAA Repair in Patients with Hostile Neck Anatomy Using Adjunctive Balloon-Expandable Stents

Hostile neck anatomy remains the predominant reason that patients are denied endovascular aneurysm repair (EVAR). We reviewed our experience of EVAR with use of prophylactic adjunctive proximal balloon-expandable stents in patients with hostile neck anatomy and adjunctive proximal balloon-expandable stents in patients with type I endoleaks. Of 140 patients who underwent EVAR between 2000 and 2004, we reviewed data for 19 patients in whom we used proximal balloon-expandable stents. By high-resolution computed tomography scan or angiography, hostile neck anatomy was classified as length <15 mm, neck diameters = 26 mm, circumferential thrombus at the proximal neck, angulated neck =60 degrees, and neck bulge or reverse taper necks. Patients were considered to have hostile anatomy if they met 1 or more of the above-cited criteria. All patients underwent AAA repair with commercially available endograft systems, Zenith (Cook, Bloomington, IN) and AneuRx (Medtronic/AVE, Minneapolis, MN). Balloon-expandable stents utilized included Cordis-Palmaz stents (17/19) and eV3 Max stents (2/19). Stents were deployed in the proximal graft with transrenal extension. AneuRx (18/19) and Zenith (1/19) endografts were used in all of the patients. Of the 19 patients, 15 had prophylactic stent placement for known hostile neck anatomy and 4 patients had stent placement for type I endoleak. Assisted primary technical success was achieved in all patients. Three patients had maldeployment of the endograft or proximal stent requiring additional endovascular interventions at the time of surgery. No endografts were deployed too low requiring stent placement. Procedure-related complications occurred in 2 of 19 patients. These included 1 operative death secondary to pneumonia and 1 patient who developed progressive renal failure. Short-term clinical success was achieved in 17 of 19 patients. Two patients required secondary interventions, 1 due to device migration with secondary conversion to open repair, and an endoleak, which, on angiogram, was a large type II endoleak successfully treated with coiling of the inferior mesenteric artery. One patient was observed to have a type II endoleak with no associated aneurysm enlargement. Short-term results suggest the use of prophylactic adjunctive balloon-expandable stents may decrease the incidence of secondary interventions related to hostile neck anatomy when used as an adjunctive measure with EVAR. Based on our experience, we feel EVAR may be offered to an expanded patient population with hostile neck anatomy with use of prophylactic balloon-expandable stents.

Anesthetic and Physiological Changes During Laparoscopy and Thoracoscopy: The Surgeon's View.

Although physiological changes during laparoscopy and thoracoscopy generally are similar to those seen during standard open procedures, these minimally invasive techniques are accompanied by some unique changes. General, regional, and local anesthesia during laparoscopy and thoracoscopy, and potential complications, are discussed. The physiological responses that are discussed include hemodynamic effects, acid-base and pulmonary effects, and hormonal effects.

A multi-institutional experience in adventitial cystic disease.

Background: Adventitial cystic disease (ACD) is an unusual arteriopathy; case reports and small series constitute the available literature regarding treatment. We sought to examine the presentation, contemporary management, and long‐term outcomes using a multi‐institutional database. Methods: Using a standardized database, 14 institutions retrospectively collected demographics, comorbidities, presentation/symptoms, imaging, treatment, and follow‐up data on consecutive patients treated for ACD during a 10‐year period, using Society for Vascular Surgery reporting standards for limb ischemia. Univariate and multivariate analyses were performed comparing treatment methods and factors associated with recurrent intervention. Life‐table analysis was performed to estimate the freedom from reintervention in comparing the various treatment modalities. Results: Forty‐seven patients (32 men, 15 women; mean age, 43 years) were identified with ACD involving the popliteal artery (n = 41), radial artery (n = 3), superficial/common femoral artery (n = 2), and common femoral vein (n = 1). Lower extremity claudication was seen in 93% of ACD of the leg arteries, whereas patients with upper extremity ACD had hand or arm pain. Preoperative diagnosis was made in 88% of patients, primarily using cross‐sectional imaging of the lower extremity; mean lower extremity ankle‐brachial index was 0.71 in the affected limb. Forty‐one patients with lower extremity ACD underwent operative repair (resection with interposition graft, 21 patients; cyst resection, 13 patients; cyst resection with bypass graft, 5 patients; cyst resection with patch, 2 patients). Two patients with upper extremity ACD underwent cyst drainage without resection or arterial reconstruction. Complications, including graft infection, thrombosis, hematoma, and wound dehiscence, occurred in 12% of patients. Mean lower extremity ankle‐brachial index at 3 months postoperatively improved to 1.07 (P < .001), with an overall mean follow‐up of 20 months (range, 0.33‐9 years). Eight patients (18%) with lower extremity arterial ACD required reintervention (redo cyst resection, one; thrombectomy, three; redo bypass, one; balloon angioplasty, three) after a mean of 70 days with symptom relief in 88%. Lower extremity patients who underwent cyst resection and interposition or bypass graft were less likely to require reintervention (P = .04). One patient with lower extremity ACD required an above‐knee amputation for extensive tissue loss. Conclusions: This multi‐institutional, contemporary experience of ACD examines the treatment and outcomes of ACD. The majority of patients can be identified preoperatively; surgical repair, consisting of cyst excision with arterial reconstruction or bypass alone, provides the best long‐term symptomatic relief and reduced need for intervention to maintain patency.

Risk factors for infectious complications with angio-seal percutaneous vascular closure devices.

Percutaneous vascular closure devices have become increasingly common in their use in both cardiac and peripheral vascular intervention. Our cases present the risk factors of repeat percutaneous vascular closure devices for subsequent infectious complications. A 43-year-old male underwent cardiac catheterization and closure with an Angio-Seal (St. Judes Medical, Inc., St. Paul, MN) device. He required a second cardiac catheterization with access gained on the same side as the previous intervention. He developed bacteremia and an infected hematoma with erosion of the femoral artery. The second case involves a 57-year-old male who underwent cardiac catheterization and closure with an Angio-Seal device. He developed a localized infection over the accessed groin site. The overall complication rate of closure devices is 2%, and 0.3% of patients have infectious complications. The high morbidity associated with these complications indicates the need to be able to identify patients who are at increased risk for these complications.

Infections of the aorta: case report and review of treatment.

Radiographic documentation of the rapid development of an aortic infection has not previously been reported. We report the case of a 68-year-old woman who presented with back pain. A computed tomographic(CT) scan documented a nondisplaced L1 compression fracture as well as an atherosclerotic but nonaneurysmal aorta. Two weeks after discharge, she developed left lower lobe pneumonia and was readmitted. A second CT scan was obtained because of continuous complaints of back pain. A contained rupture of the visceral aorta was now clearly visible. Emergent operation successfully repaired her aorta. The microorganisms responsible for aortic infection have changed since the widespread use of antibiotics. Patterns of aortic involvement have also evolved. The difficulty in making these diagnoses, the role of current antibiotic therapy, and the surgical options for these infections will be discussed.

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.

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

SummaryIn 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.