The natural history of duplex-detected stenosis after femoropopliteal endovascular therapy suggests questionable clinical utility of routine duplex surveillance.

OBJECTIVE: Duplex ultrasound (DU) surveillance (DUS) criteria for vein graft stenosis and thresholds for reintervention are well established. The natural history of DU-detected stenosis and the threshold criteria for reintervention in patients undergoing endovascular therapy (EVT) of the femoropopliteal system have yet to be determined. We report an analysis of routine DUS after infrainguinal EVT. METHODS: Consecutive patients undergoing EVT of the superficial femoral artery (SFA) or popliteal artery were prospectively enrolled in a DUS protocol (≤1 week after intervention, then at 3, 6, and 12 months thereafter). Peak systolic velocity (PSV) and velocity ratio (Vr) were used to categorize the treated artery: normal was PSV <200 cm/s and Vr <2, moderate stenosis was PSV = 200-300 cm/s or Vr = 2-3, and severe stenosis was PSV >300 cm/s or Vr >3. Reinterventions were generally performed for persistent or recurrent symptoms, allowing us to analyze the natural history of DU-detected lesions and to perform sensitivity and specificity analysis for DUS criteria predictive of failure. RESULTS: Ninety-four limbs (85 patients) underwent EVT for SFA-popliteal disease and were prospectively enrolled in a DUS protocol. The initial scans were normal in 61 limbs (65%), and serial DU results remained normal in 38 (62%). In 17 limbs (28%), progressive stenoses were detected during surveillance. The rate of thrombosis in this subgroup was 10%. Moderate stenoses were detected in 28 (30%) limbs at initial scans; of these, 39% resolved or stabilized, 47% progressed to severe, and occlusions developed in 14%. Five (5%) limbs harbored severe stenoses on initial scans, and 80% of lesions resolved or stabilized. Progression to occlusion occurred in one limb (20%). The last DUS showed 25 limbs harbored severe stenoses; of these, 13 (52%) were in symptomatic patients and thus required reintervention regardless of DU findings. Eleven limbs (11%) eventually occluded. Sensitivity and specificity of DUS to predict occlusion were 88% and 60%, respectively. CONCLUSIONS: DUS does not reliably predict arterial occlusion after EVT. Stenosis after EVT appears to have a different natural history than restenosis after vein graft bypass. EVT patients are more likely to have severe stenosis when they present with recurrent symptoms, in contrast to vein graft patients, who commonly have occluded grafts when they present with recurrent symptoms. The potential impact of routine DU-directed reintervention in patients after EVT is questionable. The natural history of DU-detected stenosis after femoropopliteal endovascular therapy suggests questionable clinical utility of routine DUS.

Endovascular treatment of ruptured axillary and large internal mammary artery aneurysms in a patient with Marfan syndrome.

Marfan syndrome is an autosomally inherited disorder affecting the synthesis of connective tissues. Vascular manifestations of Marfan syndrome include aneurysmal dilatation of the aortic root, aortic dissection, and rupture. Peripheral aneurysms are mostly reported in the iliac, femoral, and subclavian arteries. We report a Marfan patient with a ruptured axillary artery aneurysm and a large left internal mammary artery aneurysm. The axillary aneurysm was successfully excluded using covered stent grafts, and the left internal mammary artery aneurysm was effectively coiled. Duplex ultrasound imaging at 4 months and computed tomography at 9 months demonstrated complete thrombosis and exclusion of both aneurysms with patent subclavian-axillary stent grafts.

Wound chemotherapy by the use of negative pressure wound therapy and infusion.

INTRODUCTION: Although the use of negative pressure wound therapy (NPWT) is broadly efficacious, it may foster some potentially adverse complications. This is particularly true in patients with diabetes who have a wound colonized with aerobic organisms. Traditional antiseptics have been proven useful to combat such bacteria but require removal of some NPWT devices to be effective. METHODS: In this article, we describe a method of "wound chemotherapy" by combining NPWT and a continuous infusion of Dakins' 0.5% solution either as a standardized technique in one device (ITI Sved) or as a modification of standard technique in another (KCI VAC) NPWT device. The twin goals of both techniques are to effectively reduce bacterial burden and to promote progressive wound healing. RESULTS: We present several representative case examples of our provisional experience with continuous streaming therapy through 2 foam-based negative pressure devices. DISCUSSION: Wound chemotherapy was successfully applied to patients with diabetes, without adverse reactions, complications, or recolonization during the course of treatment. We believe this to be a promising method to derive the benefits of NPWT without the frequent adverse sequela of wound colonization.

Pedicled latissimus dorsi muscle flap: routine use in high-risk thoracic surgery.

Bronchopleural fistula and empyema are serious complications after thoracic surgical procedures, and their prevention is paramount. Herein, we review our experience with routine prophylactic use of the pedicled ipsilateral latissimus dorsi muscle flap. From January 2004 through February 2006, 10 surgically high-risk patients underwent intrathoracic transposition of this muscle flap for reinforcement of bronchial-stump closure or obliteration of empyema cavities. Seven of the patients were chronically immunosuppressed, 5 were severely malnourished (median preoperative serum albumin level, 2.4 g/dL), and 5 had severe underlying obstructive pulmonary disease (median forced expiratory volume in 1 second, 44% of predicted level). Three upper lobectomies and 1 completion pneumonectomy were performed in order to treat massive hemoptysis that was secondary to complex aspergilloma. One patient underwent left pneumonectomy due to ruptured-cavitary primary lung lymphoma. One upper lobectomy was performed because of necrotizing, localized Mycobacterium avium-intracellulare infection. One patient underwent right upper lobectomy and main-stem bronchoplasty for carcinoma after chemoradiation therapy. In 3 patients, the pedicled latissimus dorsi muscle was used to obliterate chronic empyema cavities and to buttress the closure of underlying bronchopleural fistulas. No operative deaths or recurrent empyemas resulted. Two patients retained peri-flap air that required no surgical intervention. We conclude that the use of transposed pedicled latissimus dorsi muscle flap effectively and reliably prevents clinically overt bronchopleural fistula and recurrent empyema. We advocate its routine use in first-time and selected reoperative thoracotomies in patients who are undergoing high-risk lung resection or reparative procedures.

Control of inferior vena cava injury using percutaneous balloon catheter occlusion.

Traumatic inferior vena cava (IVC) injuries are highly lethal and require prompt surgical intervention. Traditional methods of vascular control include manual compression, gentle clamping or balloon occlusion catheters. These open methods require direct dissection into the hematoma for visualization, which can lead to massive hemorrhage. We present a case of percutaneously delivered balloon catheter occlusion for vascular control prior to repair of an infrarenal IVC injury as a potential alternative. This approach achieves complete occlusion of the injury site and allow easier repair of the IVC, thereby reducing operative time and blood loss.

Aortoiliac aneurysm repair in kidney transplant recipients.

A potential problem during endovascular aortic aneurysm repair (EVAR) or open repair in renal allograft patients is ischemia of the transplanted kidney. In this study, kidney transplant patients who underwent aortic aneurysm repair in our institution were added to similar cases extracted from the literature to represent the basis of this work. Comparisons between patients treated with open surgery versus EVAR were performed in terms of renal function. In the EVAR group, most aneurysms were infrarenal, and 84% were treated with modular bifurcated devices. Protective kidney allograft perfusion measures were not used. The pre- and postoperative Cr was 1.69 and 1.73 mg/dL, respectively (P = .412). All EVAR patients had good outcomes. Complications included 8 endoleaks and 1 limb ischemia case. Three patients died from aortic repair-unrelated reasons. In the open group, the pre-and postoperative Cr was 1.45 and 1.37 mg/dL, respectively (P = .055). Most cases were infrarenal and mostly treated by aortobiiliac bypasses. In 16%, no adjuvant allograft perfusion was provided. In the rest, temporary axillofemoral bypasses were used most often. Most outcomes were favorable (57%). Reported procedural-related complications included arterial embolism, wound infection, and pneumonia. Deaths were reported in 5 occasions (none allograft failure dependent). No differences in Cr between EVAR and open techniques (P = .13) were seen. Aneurysm repair in kidney transplant recipients is associated with excellent renal preservation. Adverse outcomes were all allograft failure independent in both groups. EVAR without special allograft protection measures seems to be equally effective as open surgery with or without adjuvant kidney transplant perfusion.

Harvest technique for pedicled transposition of latissimus dorsi muscle: an old trade revisited.

Transposition of extrathoracic muscle flaps has been the cornerstone of treatment of a number of complex intrathoracic pathologies such as bronchopleural fistulas and residual infected pleural spaces. We present a simple step-wise technique for preservation and harvesting of the most common muscle flap employed by thoracic surgeons, namely latissimus dorsi, just prior to performing a standard posterolateral thoracotomy. Since 2004, we have successfully utilized pedicled latissimus muscle as our preferred prophylactic flap against development of postoperative bronchopleural fistulas or recurrent empyemas. This technique should be part of every thoracic surgeon's surgical armamentarium.

Renal function after elective infrarenal aortic aneurysm repair in patients with pelvic kidneys.

Pelvic kidneys complicate aortic reconstructions because of increased risk of renal ischemia. Strategies for protection include shunting, cooling, and reliance on collaterals. A review identified two congenital pelvic kidney (not solitary) and five transplanted kidney patients who underwent elective abdominal aortic aneurysm repair. For congenital pelvic kidneys, topical cooling was used in one patient while no preservation was performed for the other patient. Three transplanted kidney patients were shunted, and one had endovascular repair. Postoperative creatinine values were compared to preoperative values. The two congenital pelvic kidney patients had no significant elevation of creatinine postoperatively. The transplanted kidney patient who underwent endovascular repair had no increase in creatinine postoperatively. All transplanted kidney patients who had open repair had significant but transient increase in creatinine postoperatively. Three patients who were shunted intraoperatively had normalization of creatinine. The patient who had persistent elevation of creatinine at discharge was not shunted. Aortorenal shunting or endovascular repair in transplanted pelvic kidney patients maintains renal function. For patients with congenital pelvic kidneys and adequate collaterals, cooling and collateral perfusion is usually sufficient. Though experience is limited, endovascular repair is likely to be superior to open repair in minimizing renal ischemia.

Resistance within hemodialysis shunts predicts patency.

The authors examined the relationship between patency after thrombectomy of clotted dialysis grafts and intraoperative measurements of flow (Q), pressure gradient (PGR), and longitudinal resistance (RL). Eighteen thrombosed arteriovenous (AV) grafts underwent 21 thrombectomies. Pressures at arterial (P1) and venous (P2) ends of the AV grafts were determined with 22-gauge catheters and standard transducers; flow was measured with transit-time probes; arithmetic averaging of waveforms was used to compute mean Q, PGR, and RL. Kaplan-Meier patency curves were analyzed by using log rank methods. Mean patency for all grafts was 164 +/-152 days. For each variable, the 21 measurements were split and the patency curve for the grafts with the 11 lowest value grafts was compared to the curve representing the 10 highest value grafts. The difference between high RL versus low RL patency curves was significant with high-resistance grafts having a median patency of 55 days and low-resistance grafts having a median patency greater than 151 days (p = 0.0089). In contrast, the high Q group median patency was 151 days versus 174 days for the low Q group (p = 0.86). Median patency for the low PGR group was 115 days compared to 62 days for the high PGR group (p = 0.162). Longitudinal resistance within AV grafts, but not flow or pressure gradient, showed a significant correlation with patency after thrombectomy. Increased resistance to flow within AV grafts appears to be an important factor affecting the propensity of dialysis grafts to thrombose.

Negative pressure wound therapy with off-the-shelf components.

BACKGROUND: The KCI Wound VAC system (Kinetic Concepts, Inc, San Antonio, TX) for providing negative-pressure therapy for wounds is expensive and may not be available for patients without insurance. We have examined the feasibility of using off-the-shelf components to provide comparable negative pressure therapy at less cost. METHODS: Adhesive iodine-impregnated drape, a flat Jackson-Pratt drain (Cardinal Health, McGaw Park, IL), and foam prep sponges stapled together are used to assemble a dressing connected to wall suction (negative 75-100 mm Hg) to create negative pressure wound therapy that is relatively inexpensive (<60 US dollars component cost). RESULTS: We have used this system in more than 40 cases with results that seem comparable to the commercial system and have not seen bleeding or other complications. CONCLUSION: Off-the-shelf components can be safely employed to provide effective negative pressure therapy for wounds and skin grafts.

Predictors of mortality and management of patients with traumatic inferior vena cava injuries.

The aim of this study was to determine factors that predict mortality in patients with traumatic inferior vena cava (IVC) injuries and to review the current management of this lethal injury. A 7-year retrospective review of all trauma patients with IVC injuries was performed. Factors associated with mortality were assessed by univariate analysis. Significant variables were included in a multivariate regression analysis model to determine independent predictors of mortality. Statistical significance was determined at P < or = 0.05. A literature review of traumatic IVC injuries was performed and compared with our institutional experience. Thirty-six IVC injuries were identified (mortality, 56%; mechanisms of injury, 28% blunt and 72% penetrating). There was no difference in mortality based on mechanism of injury. Injuries with closer proximity to the heart were associated with increased mortality (P < 0.001). Univariate analysis demonstrated that nonsurvivors had a higher injury severity scale, a lower systolic blood pressure in the emergency department, a lower Glasgow coma score (GCS), and were more likely to have thoracotomies performed in the emergency department or operating room. Multivariate analysis revealed that only GCS (P = 0.03) was an independent predictor of mortality. Typical factors predicting mortality were identified in our cohort of patients, including GCS. The mechanism of injury is not associated with survival outcome, although mortality is higher with injuries more proximal to the heart. The form of management by IVC level is reviewed in our patient population and compared with the literature.

Transluminal stenting for femoropopliteal occlusive disease: analysis of restenosis by serial arteriography.

Our objective was to evaluate restenosis after stenting of femoropopliteal occlusions and the impact of percutaneous transluminal angioplasty (PTA) on recurrent stenosis. We used a retrospective analysis of contrast angiograms obtained during follow-up of stented limbs. Subjects included 27 claudicants (34 limbs) who had complete superficial femoral artery occlusion treated with PTA and Wallstents at the Veterans Adminstration Medical Center. During follow-up, 31 PTAs, three thrombolytic treatments, and one additional stenting were performed. Outcome was measured by contrast angiography. Primary patency at 1 and 3 years was 38% and 8% after stenting, and secondary patency (PTA required at least once in 21/34 limbs) was 89% and 55%, respectively. PTA performed during follow-up reduced within-stent restenosis on average from 48.3 +/- 13.6% to 22.8 +/- 18.0%. Recurrent stenosis after PTA measured 14.9 +/- 10.9 months later was 46.8 +/- 16.7%, showing little permanent impact of PTA on stenosis. Severe within-stent stenosis develops commonly after initial stenting of complete femoropopliteal occlusions. Supplemental PTA performed during follow-up provides immediate improvement in lumen diameter, but severe restenosis is still likely to recur.

Comparison of CT and catheter arteriography for evaluation of peripheral arterial disease.

Computed tomographic arteriography (CTA) has emerged as a promising technique for less invasive imaging of the lower extremity arteries. The aim of this study was to determine the concordance between CTA and catheter arteriography (CA) in patients with peripheral arterial disease (PAD). Twenty-five patients underwent both CTA and CA, and each set of images was interpreted independently by 3 readers. The infrarenal arteries were divided into 16 segments, and each segment was scored as: 1 = stenosis <50%; 2 = 50-99% stenosis; 3 = occlusion. Modal scores from 3 readers were used to compare results for each segment, with CA assumed to represent true arterial anatomy. Agreement between CTA and CA readings was defined as: concordance (modal scores were identical); moderate discrepancy (MD) (modal scores differed by 1); or severe discrepancy (SD) (modal scores differed by 2). In total, 718 segments were assessed by both CTA and CA. For all segments, the sensitivity and specificity of CTA for <50% stenosis was 86% and 90%; for 50-99% stenosis, sensitivity and specificity were 79% and 89%; and for occlusion, 85% and 98%. Above-knee (AK) CTA scores had slightly better concordance of 86.1% than below-knee (BK) readings (82.3%) (p = 0.104). Severe discrepancies between AK CTA and CA scores were observed in 1.8% of segments compared to 5.4% of BK segments (p = 0.038). Poor CTA image quality was the cause in 20% of AK segments and 28% of BK segments. Poor CA image quality was the cause in 8% of AK and 7% of BK discrepancies. Registration disagreement (stenosis observed in a level in 1 study attributed to a different level in the other) accounted for 18% of AK and 17% of BK discrepancies. In 54% of AK and 48% of BK discrepancies, neither image quality nor registration errors were identified, indicating that inherent differences in the depiction of stenosis by CA and CTA were responsible. When discrepancies caused by registration error were excluded, SD observed in BK segments (4.0%) remained significantly higher than in AK segments (1.25%) (p = 0.029), and poor CTA quality image was the most common cause (76%) of severe BK discrepancies. In AK discrepancies without an identifiable technical cause, CTA uniformly showed more stenosis, suggesting greater CTA diagnostic precision in larger vessels. In general, agreement between CTA and CA was moderately good. Compared to CA, CTA may be better at depicting stenosis in large, proximal vessels owing to the superior accuracy of cross-sectional images in the measurement of stenosis. There appeared to be poorer CT resolution and higher frequency of severe discrepancies between CTA and CA in BK arteries.

Pancreatic schwannoma. A case report and review of the literature.

CONTEXT: Pancreatic schwannomas are rare neoplasms. These tumors vary in size and two thirds are partially cystic which grossly mimic pancreatic cystic lesions. Computed tomography and magnetic resonance imaging are the primary initial imaging modalities. Definitive diagnosis is typically made at the time of laparotomy following biopsy. Surgical resection is the mainstay of treatment. CASE REPORT: A 69-year-old woman presented with abdominal pain in the epigastric and left upper quadrant. The patient had no systemic symptom and laboratory results including tumor markers were negative. A CT scan of the abdomen showed a 5 cm mass arising from the head of the pancreas. Needle biopsy revealed a mass consistent with schwannoma. At laparotomy, a large pancreatic head mass was found to encase the superior mesenteric artery, and portal vein confluence. Frozen biopsy showed schwannoma. Curative resection was deferred due to extensive vascular involvement and favorable tumor biology. A gastrojejunostomy was performed and radiation therapy was instituted post-operatively. CONCLUSIONS: Only 24 cases of pancreatic schwannoma had been previously reported. Definitive diagnosis is obtained with routine histology. Most tumors are benign and surgical resection is curative. The role of radiation therapy in the management of unresectable tumors is still unclear.