Patrick A. Stone

Vacuum-assisted fascial closure for patients with abdominal trauma.

BACKGROUNDnMassive fluid resuscitation often is required for patients with intraabdominal trauma. Subsequently, fascial closure is not always possible in this subset of patients. Under these circumstances, an initial step can be the use of a temporary abdominal closure method. The authors currently use a vacuum-assisted closure to manage the open abdomen for some of their trauma patients. They present their experience over the past 3 years.nnnMETHODSnFrom January 2000 to December 2002, 48 trauma patients were treated with temporary abdominal closure using a vacuum-assisted dressing. The ultimate management of the abdominal defect, the serum lactate levels measured in the emergency department, and the fluid balance at the last attempt to accomplish fascial closure were reviewed.nnnRESULTSnDelayed fascial closure was achieved in 23 (71.9%) of 32 patients who survived to discharge (26 of 48, 54.2%). Of the 32 patients who survived to discharge, 9 (28.1%) required an alternative closure, most often a split-thickness skin graft. Of the 16 patients who died before discharge, 8 died within 24 hours after admission. Whereas 5 of the 16 deaths occurred after delayed abdominal closure, 11 patients died without abdominal closure. Emergency department serum lactate levels above 8 mg/dL show a positive correlation with in-hospital mortality (6 of 16 patients; 38%; p = 0.001) and mortality within 24 hours of admission (6 of 8 patients; 75%; p = 0.003). Admission lactate levels were not associated with the type of closure achieved. However, primary closure was associated with a significant decrease in lactate levels during the first 12 hours. Complications included five abdominal abscesses, two enterocutaneous fistulas, and one split-thickness skin graft failure.nnnCONCLUSIONSnPatients requiring temporary abdominal closure have a significant in-hospital mortality rate of 33%. Delayed primary closure with vacuum assistance was achieved for 71.9% of the surviving patients. Maintaining a negative or total positive fluid balance of less than 20 L before the last attempted fascial closure improves successful closure rates, as seen in 19 of 22 patients (86.4%). The vacuum-assisted closure technique also enabled successful primary closure for two patients with extreme delay (>8 days). Elevated serum lactate levels are significantly correlated with early and in-hospital mortality. A significant decrease in lactate level during the first 12 hours is associated with achievement of primary closure.

An Overview of Matrix Metalloproteinases in the Pathogenesis and Treatment of Abdominal Aortic Aneurysms

Recent basic and clinical research has established a link between the pathogenesis of abdominal aortic aneurysms (AAA) and matrix metalloproteinases (MMP). The discovery of the influence of MMPs on in vitro and in vivo aneurysm development has yielded promising information that may eventually decode the pathogenetic factors affecting the initiation and growth rate of AAAs. In this review, an analysis of MMPs involved in AAA disease is presented, including the data from recent research studies and planned clinical drug trails designed to retard the AAA growth by inhibiting MMP activity.

Meckel diverticulum: ten-year experience in adults.

Objectives: Meckel diverticulum, a congenital gastrointestinal anomaly, is well studied in pediatrics, but less so in the adult population. At the Charleston Area Medical Center (CAMC), in addition to the removal of Meckel diverticula in symptomatic patients, diverticula are commonly removed when found incidentally during other procedures. We present our experience over the past ten years with this condition, unusual in the adult population. Methods: From 1992 to 2002 at the Charleston Area Medical Center, Meckel diverticula were removed from 47 patients older than 18 years of age. We reviewed the age, sex, indication for removal, pathologic findings, and perioperative complications of these cases. Results: Diverticula were removed most often from female patients (31 female, 66%; 16 male, 34%). The removal of the diverticulum was incidental in 35 patients (74.5%) and symptomatic in 12 (25.5% percent). Symptomatic patients presented with: obstruction (n = 4), acute bleeding (n = 1) and diverticulitis (n = 7). Female patients were significantly less likely than male patients to be symptomatic (4 of 31, 13% among females, and 8 of 16, 50% among males; P < 0.05). Heterotopic mucosa was identified in six patients, two of whom were symptomatic at the time of removal. Gastric mucosa was found in all six of the diverticula with ectopic mucosa, although one of the six had a mixed gastric and pancreatic cell population. One asymptomatic patient had a malignancy identified as a 1.5 cm carcinoid with no evidence of metastatic disease. An adenomyoma was found incidentally in one patient upon pathologic evaluation. Hospital complications that could possibly be attributed to removal of diverticula included two wound infections and two anastomotic leaks requiring exploration (8.5% morbidity). Complications were experienced by two asymptomatic females, one asymptomatic male, and a symptomatic male. There were no mortalities. Conclusions: Meckel diverticulum is found infrequently in the adult population. Adults rarely become symptomatic, but symptoms that do arise are associated with significant morbidity. Complications directly attributable to diverticulum removal are uncommon; however, those that do occur are often life threatening. Therefore, incidental removal of asymptomatic diverticula, particularly in women, is not recommended.

Current Indications for Preoperative Inferior Vena Cava Filter Insertion in Patients Undergoing Surgery for Morbid Obesity

Background: Pulmonary embolus is a potentially lethal complication in patients undergoing surgery for morbid obesity. In a select group of patients at high risk for venous thromboembolic events (VTE), we have chosen to prophylactically insert inferior vena cava filters via a jugular percutaneous approach. We propose guidelines for preoperative insertion of inferior vena cava filters in patients with clinically significant obesity. Methods: All patients who underwent preoperative insertion of inferior vena cava (IVC) filters as prophylaxis for pulmonary emboli were reviewed. Data regarding body mass index (BMI), prior history of venous thromboembolism, current anticoagulant usage, as well as other patient data were compiled and analyzed. Additionally, all operative notes were reviewed, and operative data were analyzed and compared. Results: 14 patients underwent preoperative IVC filter placement before gastric bypass. Mean patient age was 49.1 ± 1.52 years and mean BMI was 56.5 ± 4.45 kg/m2. No complications occurred due to preoperative filter placement, and no pulmonary emboli occurred in this group. Indications for preoperative IVC filter insertion included prior pulmonary embolus (6), prior deep venous thrombosis (7), and lower extremity venous stasis (1). Conclusions: Vena caval filter placement in the preoperative period can be undertaken safely in bariatric patients. We recommend that routine preoperative vena caval filter placement should be undertaken in all bariatric patients with prior pulmonary embolus, prior deep venous thrombosis, evidence of venous stasis, or known hypercoagulable state. Possible roles for IVC filter placement in this patient population are expanding as more data is acquired.

Complications related to femoral artery access for transcatheter procedures.

Percutaneous-based procedures continue to increase as endovascular techniques improve and provide a less morbid approach than the open vascular procedures. The most common complications associated with either cardiac interventions or peripheral interventions involve the access point of the procedure. The retrograde femoral access has and is currently the most frequently used arterial access. Vascular surgeons have been responsible for management of complications following femoral-based procedures and now are a significant contributor to catheter-based diagnostic and interventional procedures. This review provides in-depth review of the literature on specific complications encountered during percutaneous femoral artery puncture. This review includes access complications related to the method of obtaining access (ie, best pulse fluoroscopic guided), direction of access either retrograde or antegrade, risk factors and incidence of complications based on best literature sources, and management strategies for specific complications.

Regional antibiotic delivery for the treatment of experimental prosthetic graft infections.

OBJECTIVESnTo evaluate the efficacy of antibiotic-impregnated polymethylmethacrylate (PMMA) beads in eradication of an arterial prosthetic graft methicillin-resistant Staphylococcus aureus (MRSA) biofilm in an experimental animal model.nnnMETHODSnForty rats underwent subcutaneous implantation of a MRSA-colonized arterial polytetrafluoroethylene (PTFE) 1 x 1 cm wafer on the back. The effect of regional antibiosis produced by antibiotic PMMA bead placement adjacent to the infected PTFE wafer was determined using four 10-animal study groups: control (no antibiotic), PMMA bead with no antibiotic, PMMA bead with 10% vancomycin, and PMMA bead with 10% daptomycin. After 3 d, the PTFE wafers were explanted and quantitative biofilm cultures, expressed as colony-forming units (CFU) per graft wafer, performed using real-time polymerase chain reaction to assess MRSA eradication. No systemic antibiotic was administered. Bioassays of antibiotic bead bacteriocidal were performed by measuring zone of inhibition diameters on MRSA colonized agar culture plates prior to and following graft explantation.nnnRESULTSnAll animal tolerated implantation of the MRSA-infected PTFE wafer and survived the 3 d until graft explantation. Quantitative biofilm cultures demonstrated a significant decrease (P < 0.01) in MRSA CFUs present on the PTFE wafer surfaces in the presence of both the vancomycin- and daptomycin-impregnated beads compared to controls and plain PMMA beads. Both vancomycin and daptomycin PMMA beads retained antibacterial activity after 3 d of implantation with decrease in zones of inhibition of 15% and 45%, respectively.nnnCONCLUSIONSnRegional antibiotic delivery using an antibiotic-impregnated PMMA bead reduced the bacterial biofilm concentration in experimental subcutaneous pocket model of vascular surgical site infection. The delivery of antibiotics via a PMMA bead may be a useful adjunct in the treatment of vascular surgical site infection.

Superior Mesenteric Artery Stent Fracture Producing Stenosis and Recurrent Chronic Mesenteric Ischemia: Case Report

Endovascular modalities are being increasingly employed in the treatment of a variety of vascular diseases. With new technologies come novel complications, and one such complication unique to endovascular surgery is stent fracture. We present two cases of stent fracture following stenting of the superior mesenteric artery and discuss possible causes and treatments.

Increasing Endovascular Intervention for Claudication: Impact on Vascular Surgery Resident Training

Purpose: To audit the caseloads of vascular surgery residents in the management of disabling claudication and assess the influence of endovascular procedures on overall operative experience. Methods: A retrospective review was conducted of vascular surgery resident experience in the open and endovascular management of lower limb claudication during two 3-year periods (January 2000 to December 2002 and January 2003 to December 2005). The time periods differed with regard to number of surgical faculty with advanced endovascular skills (3 in the first period and 4 in the second) and the availability of portable operating room angiography equipment. Results: During the 6-year period, the operative logs of vascular surgery residents indicated participation in 283 procedures [170 (60%) open surgical interventions, including 146 suprainguinal procedures] performed for claudication. The number of procedures increased by 62% (p<0.05) from the first period (n=108) to the second (n=175). Endovascular intervention to treat aortoiliac occlusive disease increased 4-fold (14 versus 56 interventions, p=0.01) compared to a decrease in open (bypass grafting, endarterectomy) surgical repair (45 to 31 procedures, p=0.22). The greatest change in resident experience was in endovascular intervention of infrainguinal occlusive disease: the case volume increased from 4 to 39 procedures (p=0.07) during the 2 time intervals. By contrast, the number of open surgical bypass procedures was similar (45 versus 49) in each 3-year period. Conclusion: An audit of resident experience demonstrated intervention for claudication has increased during the past 6 years. The increased operative experience reflects more endovascular treatment (atherectomy, angioplasty, stent-graft placement) of femoropopliteal and aortoiliac occlusive disease, but no decrease in open surgical operative experience for claudication. This increase in endovascular intervention may be related to a decrease in the threshold for intervention.

Evolving Microbiology and Treatment of Extracavitary Prosthetic Graft Infections

The authors report the microbiology and outcomes following an individualized treatment algorithm for extracavitary (EC) prosthetic graft infection, including the use of graft preservation and in situ graft replacement techniques. A retrospective 8-year review of 87 patients treated for EC prosthetic graft infections was carried out. The treatment algorithm included culture-specific antibiotic therapy, surgical site debridement with antibiotic bead placement, selected graft preservation with muscle flap coverage, or graft excision with in situ conduit replacement. Outcomes measured included death, limb loss, and recurrent infection. It was found that present-day management of EC prosthetic graft infections is associated with lower mortality and morbidity despite changes in microbiology and the increased application of graft preservation and in situ grafting treatments.

Early and Late Clinical Outcomes of Endovascular Aneurysm Repair in Patients with an Angulated Neck

This study analyzed the clinical outcome in endovascular aneurysm repair (EVAR) patients with an angulated aortic neck. Two hundred thirty-eight EVAR patients underwent postoperative duplex ultrasonography and/or computed tomographic angiography, which was repeated every 6 to 12 months. Aortic neck angle was classified into < 45° (A1, n= 129), ≥ 45 to < 60° (A2, n = 43), and ≥ 60° (A3, n = 42). The perioperative complication rates for groups A1, A2, and A3 were 13%, 5%, and 29%, respectively (p = .006). Proximal type I early endoleaks occurred in 9%, 33%, and 38% in groups A1, A2, and A3, respectively (p < .0001). Intraoperative proximal aortic cuffs were needed in 7%, 28%, and 33% in groups A1, A2, and A3, respectively (p < .0001). However, the rate of late reintervention was comparable in all groups. Postoperatively, the size of abdominal aortic aneurysm decreased or remained unchanged in 97%, 95%, and 84% in A1, A2, and A3, respectively (p = .0147). The rates of freedom from late type I endoleak at 1, 2, and 3 years were 90%, 85%, and 85% for A1; 74%, 74%, and 68% for A2; and 64%, 64%, and 53% for A3 (p = .0013). EVAR can be used for patients with an angulated aortic neck but was associated with a higher rate of early and late type I endoleaks and early interventions.