Krishna M. Jain

Predictors of surgical site infection after open lower extremity revascularization

Objective: Surgical site infection (SSI) after open lower extremity bypass (LEB) is a serious complication leading to an increased rate of graft failure, hospital readmission, and health care costs. This study sought to identify predictors of SSI after LEB for arterial occlusive disease and also potential modifiable factors to improve outcomes. Methods: Data from a statewide cardiovascular consortium of 35 hospitals were used to obtain demographic, procedural, and hospital risk factors for patients undergoing elective or urgent open LEB between January 2012 and June 2015. Bivariate comparisons and targeted maximum likelihood estimation were used to identify independent risk factors of SSI. Adjusted odds ratios (ORs) were calculated for patient demographics, comorbidities, operative details, and hospital‐level factors. Results: Our study population included 3033 patients who underwent 703 femoral‐femoral bypasses, 1431 femoral‐popliteal bypasses, and 899 femoral‐distal vessel bypasses. An SSI was diagnosed in 320 patients (10.6%) ≤30 days after the index operation. Adjusted patient and procedural predictors of SSI included renal failure currently requiring dialysis (OR, 4.35; 95% confidence interval [CI], 3.45‐5.47; P < .001), hypertension (OR, 4.29; 95% CI, 2.74‐6.72; P < .001), body mass index ≥25 kg/m2 (OR, 1.78; 95% CI, 1.23‐2.57; P = .002), procedural time >240 minutes (OR, 2.95; 95% CI, 1.89‐4.62; P < .001), and iodine‐only skin preparation (OR, 1.73; 95% CI, 1.02‐2.91; P = .04). Hospital factors associated with increased SSI included hospital size <500 beds (OR, 2.22; 95% CI, 1.09‐4.55; P = .028) and major teaching hospital (OR, 1.66; 95% CI, 1.07‐2.58; P = .024). SSI resulted in increased risk of major amputation and surgical reoperation (P < .01), but did not affect 30‐day mortality. Conclusions: SSI after LEB is associated with an increase in rate of amputation and reoperation. Several patient, operative, and hospital‐related risk factors that predict postoperative SSI were identified, suggesting that targeted improvements in perioperative care may decrease complications and improve vascular patient outcomes.

Traumatic aorto-caval fistula

Trauma is an unusual cause of fistula formation between the aorta and the inferior vena cava. Two cases of traumatic aorto-caval fistula treated at the New Jersey Medical School affiliated hospitals are presented and the literature on traumatic aorto-caval fistula reviewed. We found 14 previously reported cases. Delayed repair was performed in 12 (86%). Delays ranged from 5 days to 12 years postinjury. Cardiac decompensation, judged either clinically or by cardiomegaly evident on chest X-ray, was present in 75% of the patients undergoing delayed repair. The techniques available for repair and the criteria for utilizing delayed repair are discussed. In young, previously healthy patients, usually with smaller fistulae, we conclude that delayed repair can be used.

Office-based endovascular suite is safe for most procedures.

OBJECTIVE This study was conducted to identify the safety of endovascular procedures in the office endovascular suite and to assess patient satisfaction in this setting. METHODS Between May 22, 2007, and December 31, 2012, 2822 patients underwent 6458 percutaneous procedures in an office-based endovascular suite. Demographics of the patients, complications, hospital transfers, and 30-day mortality were documented in a prospective manner. Follow-up calls were made, and a satisfaction survey was conducted. Almost all dialysis procedures were done under local anesthesia and peripheral arterial procedures under conscious sedation. All patients, except those undergoing catheter removals, received hydrocodone and acetaminophen (5/325 mg), diazepam (5-10 mg), and one dose of an oral antibiotic preprocedure and three doses postprocedure. Patients who required conscious sedation received fentanyl and midazolam. Conscious sedation was used almost exclusively in patients having an arterial procedure. Measurements of blood urea nitrogen, creatinine, international normalized ratio, and partial thromboplastin time were performed before peripheral arteriograms. All other patients had no preoperative laboratory tests. Patients considered high risk (American Society of Anesthesiologists Physical Status Classification 4), those who could not tolerate the procedure with mild to moderate conscious sedation, patients with a previous bad experience, or patients who weighed >400 pounds were not candidates for office based procedures. RESULTS There were 54 total complications (0.8%): venous, 2.2%; aortogram without interventions, 1%; aortogram with interventions, 2.7%; fistulogram, 0.5%; catheters, 0.3%; and venous filter-related, 2%. Twenty-six patients required hospital transfer from the office. Ten patients needed an operative intervention because of a complication. No procedure-related deaths occurred. There were 18 deaths in a 30-day period. Of patients surveyed, 99% indicated that they would come back to the office for needed procedures. CONCLUSIONS When appropriately screened, almost all peripheral interventions can be performed in the office with minimal complications. For dialysis patients, outpatient intervention has a very low complication rate and is the mainstay of treatment to keep the dialysis access patent. Venous insufficiency, when managed in the office setting, also has a low complication rate. Office-based procedural settings should be seriously considered for percutaneous interventions for arterial, venous, and dialysis-related procedures.

Analysis of factors influencing patency of polytetrafluoroethylene prostheses for limb salvage

This clinical review of 70 polytetrafluoroethylene femoropopliteal and femoral-distal (tibial or peroneal) bypasses for limb salvage analyzes factors that influence graft patency. Patients with “good” angiographic run-off (n = 26) had a significantly better (P < 0.01) cumulative patency rate when compared to patients with “poor” (n = 43) angiographic run-off. Other factors which had a significant influence on graft patency over the 2-year follow-up included site of distal anastomosis (femoropopliteal versus femoral-distal), and previously failed femoropopliteal bypass. Patients with a preoperative ankle/brachial Doppler pressure index of less than 0.2 had a 67% occlusion rate during the first postoperative month. Thrombectomy and distal revisions (patch or jump graft) following graft occlusion did not significantly prolong graft patency.

Hemodynamics of an anastomotic arteriovenous fistula.

Various vascular surgical techniques have been employed to increase both graft patency and limb survival when the prognosis for limb salvage in arteriosclerotic patients is especially poor due to a diseased outflow tract. Ibrahim et al described the creation of an anastomotic arteriovenous fistula in distal tibial bypasses as the reconstructive procedure of choice in severely ischemic extremities unsalvageable by more conventional methods. This study presents the hemodynamics of an anastomotic arteriovenous fistula under such circumstances. Four adult mongrel dogs were anesthesized, and a femoral artery and vein were exposed from the groin to the knee. The femoral artery was ligated in midthigh, and the ligated segment was than bypassed using an umbilical vein graft. The distal anastomosis included an arteriovenous fistula. Flow was measured electromagnetically, and pressure was measured with intravascular catheters attached to strain gauges. The creation of an anastomotic arteriovenous fistula rapidly leads to a reversal of flow in the distal artery, distal arterial hypotension, and distal venous hypertension. Its clinical use in contraindicated as a result of our experimental observations.

Effects of vasopressin on cardiac output and its distribution in the subhuman primate

The effects of vasopressin, when administered as intravenous bolus injections and infusions, on cardiac output and the distribution of blood flow to the splanchnic vascular beds were studied in six anesthetized rhesus monkeys. Vasopressin as bolus injections caused dose-dependent decreases in superior mesenteric arterial blood flow. However, small reductions in cardiac output were observed only at the highest doses concomitant with increases in systemic arterial pressure. When vasopressin was infused at the highest dose (5 X 10(-2) units kg-1 min-1) for 10 minutes, cardiac output was unaffected; but sustained reductions in superior mesenteric arterial blood flow and increases in arterial pressure and total peripheral resistance were observed. Infusions of vasopressin (5 X 10(-3) units kg-1 min-1) caused significant and sustained reductions in superior mesenteric arterial blood flow and increases in arterial pressure but no measurable effects on cardiac output or total peripheral resistance. However, there was a significant redistribution of blood flow away from the stomach, small and large intestines, spleen, and pancreas toward the liver (hepatic artery), with no statistically significant change in renal blood flow. On the assumption that comparable responses exist among primates, these data support the clinical use of vasopressin to control gastrointestinal hemorrhage and to offer a probably ideal dose and route of administration.

Reoperation for Recurrent Carotid Stenosis: A Ten-Year Experience

Owing to the supposed risks of reoperation, carotid stenting has been proposed as a treatment for carotid restenosis. The purpose of this study is to determine the safety and efficacy of carotid reoperation. From March 1988 to March 1997, 40 patients, 18 men and 22 women (mean age: 65 years) underwent a total of 43 redo carotid procedures by our group. Two patients had both sides repaired and one required a second reoperation. Symptomatic recurrent carotid stenosis (>70%) was the indication in 25 reoperations and asymptomatic high-grade stenosis (>80%) was the indication in 18. The initial operation in 35 reoperations was carotid endarterectomy (CEA) with primary closure and in eight it was CEA with a prosthetic patch. The interval to recurrence was less in the 24 reoperations in patients who had myointimal hyperplasia (21 months) compared with 17 reoperations in patients with recurrent atherosclerosis (90 months). The other two reoperations were for an intimal flap 2 months after the original CEA, and for operative dilation of fibromuscular dysplastic bands missed on magnetic resonance angiography (MRA), distal to the site of a previous CEA. The technique of reoperation included redo CEA in two, CEA with vein patch in eight, CEA with prosthetic patch in 22, vein interposition graft in five, and prosthetic interposition graft in five. In addition, operative dilation with an arterial dilator was used in one reoperation. No perioperative strokes or deaths occurred other than one patient who died from cardiac complications following combined CEA and coronary artery bypass grafting. Operative morbidity consisted of pneumonia in one patient, reversible cranial nerve injury in four, and hematoma requiring evacuation in two. During follow-up (mean: 34 months), carotid occlusion resulted in a mild stroke in one patient, there were 10 late deaths not related to carotid disease, one patient required a reoperation, and three patients were lost to follow-up. The authors conclude that reoperation for recurrent carotid stenosis, using standard vascular techniques, is both safe and effective; it should continue to be the mainstay of treatment when intervention is required.

Cross-over bypass to axillary vein in haemodialysis patients

Two patients are described in whom cross-over bypass to axillary vein was performed to salvage brachio-basilic grafts. Both patients had massively swollen arms because of subclavian vein thrombosis and functioning grafts. Their grafts were used for prolonged periods after the corrective operation.

Protective effect of a splenic extract in mice with endotoxemia.

We have previously described the isolation of a lipoidal splenic extract (LSE) that demonstrated a variety of hematologic effects including inhibition of platelet aggregation both in vivo and in vitro. Since endotoxin causes platelet aggregation and microembolism the protective effect of LSE in endotoxemia was examined in the present study. Both young and elderly Swiss mice given LSE 2--3 hours before endotoxin challenge showed a statistically significant increase in survival compared with saline-treated controls. However, no significant improvement in survival was noted when LSE was administered at the same time as endotoxin. These results add further support to the role of the spleen in the control of infection.

Changing practice paradigms: Negotiating your future

There are many recent and ongoing changes in the practice of medicine from a business standpoint as well as in overall practice management. Economic and lifestyle desires have pushed many physicians to a decision point of whether or not to join a large multispecialty group or to sell their practice and become an employee of a hospital system. There are advantages and disadvantages to both options; however, deciding on the most appropriate path for each individual can be a daunting task. At our recent breakfast session at the vascular annual meeting in Chicago, Illinois, in June 2011, we brought to light these topics to try and help enlighten physicians on which option may be right for them. There is no single answer/option that will fit every practice, but discussion for various practice management designs are outlined and critiqued. This article cannot fully discuss each view in the allotted space, but it is designed to encourage thought and discussion among the vascular surgical community as a whole.