Teng C. Lee

Results With a Selective Revascularization Strategy for Left Subclavian Artery Coverage During Thoracic Endovascular Aortic Repair

BACKGROUND The need for routine left subclavian artery (LSCA) revascularization when this vessel is covered during thoracic endovascular aortic repair remains controversial. We report our results with a selective LSCA revascularization strategy during thoracic endovascular aortic repair. METHODS Between May 2002 and March 2010, 287 thoracic endovascular aortic repair procedures were performed at our institution. LSCA coverage occurred in 145 (51%), which form the basis of this report. RESULTS Left subclavian artery revascularization was performed in 32 patients (22%) through a left common carotid-LSCA bypass. Indications for selective LSCA revascularization included spinal cord protection in 10, patent pedicled left internal mammary artery graft in 9, left arm ischemia after LSCA coverage in 5, origin of the left vertebral artery from the arch in 4, dialysis access in the left arm in 2, and vertebrobasilar insufficiency in 2. There were no instances of dominant left vertebral artery. The revascularized and non-revascularized groups had similar rates of death (6.3% vs 1.8%; p=0.21), stroke (3.1% vs 3.5%; p>0.99), permanent paraplegia or paraparesis (3.1% vs 0%; p=0.22), and type II endoleak (4.3% vs 6.5%; p>0.99). There were no instances of ischemic stroke related to left posterior circulation hypoperfusion. Four complications of carotid-subclavian bypass occurred in 3 patients (9.4%). CONCLUSIONS Selective LSCA revascularization is safe and does not appear to increase the risk of neurologic events. Further, subclavian revascularization is not without complications, which should be considered with regards to a nonselective revascularization strategy.

Results of 141 Consecutive Minimally Invasive Tricuspid Valve Operations: An 11-Year Experience

BACKGROUND Reports of minimally invasive tricuspid valve operations are rare. We reviewed our experience and results of tricuspid valve operation using mini-thoracotomy during an 11-year period. METHODS Consecutive patients (n = 141) undergoing tricuspid valve operation using mini-thoracotomy were retrospectively analyzed. Access was through a 6-cm right thoracotomy and cardiopulmonary bypass was instituted by means of the femoral artery (n = 16) or ascending aorta (n = 125) with augmented venous return. In most cases, vacuum assist without caval occlusion and snaring the cavae was used to minimize mediastinal dissection. In all cases, the tricuspid valve operation was done with the heart unclamped, and the heart either beating or fibrillating. RESULTS Seventy-three percent (103 of 141 patients) of the patients underwent combined mitral and tricuspid valve operations. The tricuspid valve was repaired instead of being replaced in 61% (86 of 141 patients). Previous sternotomy was present in 49% (69 of 141 patients). The average patient age was 64 years. Conversion rate to median sternotomy was only 3% (4 of 141 patients). The mean cardiopulmonary bypass time was 216 minutes. Thirty-day mortality was 2.1% (3 of 141 patients). Stroke occurred in 2.8% (4 of 141 patients), and reexploration for bleeding occurred in 5.6% (8 of 141 patients). The stroke rate was 3 of 16 patients (18.8%) using mini-thoracotomy through femoral cannulation versus 1 of 125 patients (0.8%) through aortic cannulation (p = 0.005). CONCLUSIONS In this largest reported series of patients undergoing tricuspid valve operation, mini-thoracotomy provides excellent short-term morbidity and mortality in these high-risk patients while avoiding redo sternotomy with a low conversion rate. Mini-thoracotomy with aortic cannulation is an attractive alternative approach to the tricuspid valve, particularly in patients with previous sternotomy.

Ex Vivo Adenoviral-Mediated Gene Transfer to Lung Isografts During Cold Preservation

BACKGROUND Although whole-organ gene transfer has been reported in heart and liver transplant models, it has not been well characterized in lung grafts. The aim of this study was to determine the feasibility of ex vivo gene transfer to rat lung isografts during cold preservation using an adenoviral vector. METHODS F344 rats, divided into four groups, underwent orthotopic left lung transplantation. In group I, lung grafts were flushed with adenovirus carrying the beta-galactosidase gene. After storage at 10 degrees C, grafts were implanted in recipient animals. Group II underwent the same procedure but graft storage was at 4 degrees C. Groups III (10 degrees C) and IV (4 degrees C) served as controls. On postoperative day 5, recipients were sacrificed, and native and transplanted lungs were examined. RESULTS In group I, all animals showed successful, albeit patchy, gene expression. This occurred in 2 of 4 animals in group II, the other 2 showing no expression. Transduced cells were consistent morphologically with endothelial cells and pneumocytes. A minimal mononuclear inflammatory infiltrate was present. Control groups showed no transduction. CONCLUSIONS It is feasible to perform ex vivo adenoviral-mediated gene transfer to rat lung isografts during cold preservation.

Liposome-mediated gene transfer to lung isografts

OBJECTIVES Our objective were to determine the feasibility, efficacy, and safety of in vivo and ex vivo liposome-mediated gene transfer to lung isografts. METHODS Fischer rats were divided into three main groups: (1) Nontransplant setting: Liposome-chloramphenicol acetyl transferase cDNA was intravenously injected, and lungs were harvested at different time points: 2, 6, 12, and 24 hours; 2, 5, 8, and 21 days (n = 3). Chloramphenicol acetyl transferase activity was determined in lungs, hearts, livers, and kidneys. The distribution and type of transfected cells were evaluated by in situ hybridization. Lung toxicity was assessed by arterial oxygen tension, histology, and tumor necrosis factor-alpha levels. (2) In vivo graft transfection: Left lungs were transplanted 6 hours, 4 hours, and 15 minutes after intravenous injection and were assessed for chloramphenicol acetyl transferase activity and arterial oxygen tension on postoperative day 2. (3) Ex vivo graft transfection: Grafts were infused ex vivo with either 660 micrograms (n = 3) or 330 micrograms (n = 3) of DNA complexed to liposomes and stored at 10 degrees C for 4 hours. Chloramphenicol acetyl transferase activity was assessed 44 hours after transplantation. RESULTS Transgene expression was detected in endothelial cells, macrophages, and interstitial cells. Chloramphenicol acetyl transferase activity was present as early as 2 hours, increased significantly between 6 hours and 8 days, and then decreased to minimal levels by 21 days. Chloramphenicol acetyl transferase activity was greatest in donor lungs and hearts and minimal in livers and kidneys. Arterial oxygen tension was normal in treated animals. Inflammation was minimal, and tumor necrosis factor-alpha levels increased only sevenfold in treated animals. CONCLUSION In vivo and ex vivo liposome-mediated gene transfer to lung isografts allows significant transgene expression with minimal effects on graft function.

In situ bending of a thoracic stent-graft: A proposed novel technique to improve thoracic endograft seal

Purpose: To demonstrate the feasibility of a novel technique that modifies the configuration of a thoracic stent-graft after deployment to comply with the arch curvature. Technique: The principle of a Bowden cable has been applied to direct a conventional thoracic stent-graft in situ after deployment. A suture placed at the proximal inner curve of a conventional thoracic stent-graft is fitted with a sliding, self-locking knot attached to a line that runs inside a catheter through the central rod of the stent-graft. Traction applied to this line directs the endograft post deployment, which allows for better apposition to the aortic wall. Shortening the inner curve makes the stent-graft bend. The extent of bending is fully controlled by the surgeon and held in place with the sliding knot. A release mechanism allows removal of all luminal components of the mechanism. Conclusion: The described technique of directing a thoracic stent-graft in situ seems feasible and enables better apposition of the stent-graft in a glass model. It may improve the durability of thoracic stent-grafts in the aortic arch.

Thoracic endografting in a patient with hereditary hemorrhagic telangiectasia presenting with a descending thoracic aneurysm

A 53-year-old woman with no classic risk factors for aneurysm disease presented with the sudden onset of chest pain and dyspnea. A large descending thoracic aortic aneurysm with focal type B dissection was identified and excluded by emergency thoracic endografting. Further postoperative evaluation revealed a history of epistaxis, perioral telangiectasias, hepatic hypervascularity, and a mutation in the gene expressing activin receptor-like kinase 1 (ALK1), leading to a diagnosis of hereditary hemorrhagic telangiectasia. Aortic aneurysms associated with hereditary hemorrhagic telangiectasia are extremely rare, and to our knowledge, this is the first report of thoracic endografting in this patient population.

Contemporary management and outcomes of acute type A aortic dissection: An analysis of the STS adult cardiac surgery database.

Management of acute type A aortic dissection (AAAD) is challenging and operative strategies are varied. We used the STS Adult Cardiac Surgery Database (STS ACSD) to describe contemporary surgical strategies and outcomes for AAAD.

Idarucizumab (Praxbind) for reversal of pradaxa prior to emergent repair of contained ruptured transverse arch aneurysm

Idarucizumab before cardiopulmonary bypass was used for the reversal of dabigatran during an emergent frozen elephant trunk repair of a transverse arch aneurysm. Reversal was successful and minimal not massive transfusion was required with no abnormal sequelae seen with use before cardiopulmonary bypass.

Femorofemoral Shunt During Surgery for Acute DeBakey Type 1 Dissection to Treat Peripheral Extremity Malperfusion

Peripheral extremity ischemia in patients presenting with a DeBakey type 1 aortic dissection is an independent predictor for mortality. We present a patient with a DeBakey type 1 aortic dissection and peripheral extremity malperfusion that underwent simultaneous aortic repair and percutaneous femorofemoral shunt with arterial sidearm. Our approach allows for immediate peripheral extremity reperfusion and subsequent objective determination of the necessity of femorofemoral bypass via perfusion pressures.