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Biomedical subjects

Randall K Wolf

Publications and source records attributed to Randall K Wolf.

14 recordsLinked to original sources

The PRoject of Ex-vivo Vein graft ENgineering via Transfection IV (PREVENT IV) trial: study rationale, design, and baseline patient characteristics.

BACKGROUND: Coronary artery bypass graft (CABG) surgery with autologous vein graft (VG) conduit is one of the most frequently performed operations in the United States. Unfortunately, many VGs become occluded during long-term follow-up largely because of neointimal hyperplasia. A novel approach to preventing neointimal hyperplasia is with the double-stranded oligonucleotide edifoligide (Corgentech Inc, South San Francisco, Calif). Edifoligide inhibits E2F, a transcription factor that activates cell-cycle genes responsible for neointimal hyperplasia. METHODS: PREVENT IV is a phase-III, multicenter, randomized double-blind placebo-controlled trial of ex vivo treatment of autologous VGs with edifoligide in patients undergoing initial CABG surgery. The primary end point is VG failure, defined as death or > or =75% stenosis in a treated VG at 12- to 18-month angiographic follow-up. Secondary end points include major adverse cardiac events through at least 5 years and adverse events through 30 days. RESULTS: Enrollment of 3014 patients from 107 sites was completed on October 22, 2003. The baseline and procedural characteristics of the PREVENT IV population are generally well matched to a contemporary population of patients undergoing initial CABG from the Society of Thoracic Surgeons National Database. Angiographic follow-up is ongoing and scheduled to be completed in March 2005. CONCLUSIONS: The PREVENT IV data will establish whether VG pretreatment with an E2F transcription factor decoy, edifoligide, can improve graft patency and reduce the long-term morbidity and mortality of patients undergoing CABG surgery.

Aged↗

Video-assisted bilateral pulmonary vein isolation and left atrial appendage exclusion for atrial fibrillation.

OBJECTIVE: Pulmonary vein isolation is curative in selected patients with atrial fibrillation. The objective of this study was to assess the feasibility and safety (midterm results) of video-assisted thoracoscopic epicardial pulmonary vein isolation. METHODS: Twenty-seven patients (22 male patients) with atrial fibrillation (18 paroxysmal, 4 persistent, and 5 permanent; average age, 57 years) underwent bilateral video-assisted thoracoscopic off-pump epicardial pulmonary vein isolation and exclusion of the left atrial appendage. All patients had had unsuccessful drug therapy or were intolerant to antiarrhythmic drug therapy or were intolerant to warfarin. The approach included two 10-mm ports and one 5-cm working port (non-rib spreading) bilaterally. Pulmonary vein isolation was achieved bilaterally by using a bipolar radiofrequency device. The left atrial appendage was excised with a surgical stapler. RESULTS: Bilateral pulmonary vein isolation and left atrial appendage excision was performed successfully in all patients. There were no conversions to sternotomy or thoracotomy. All patients were extubated in the operating room. Postoperative complications in 3 patients were minor and resolved within 48 hours. One morbidly obese patient had more serious complications related to comorbid conditions. Average postoperative follow-up is approximately 6 months (173.6 days). Twenty-three patients have been followed up for greater than 3 months, and 21 of these patients are free of atrial fibrillation (91.3%). The results of magnetic resonance angiography were normal (no pulmonary vein stenosis) in 12 of 12 patients evaluated 3 to 6 months postoperatively. CONCLUSIONS: Bilateral video-assisted thoracoscopic pulmonary vein isolation with excision of the left atrial appendage is feasible and safe and offers a promising, new, minimally invasive, beating-heart approach for curative surgical treatment of atrial fibrillation.

Adult↗

Facilitated MIDCAB using a magnetic coupling device.

A 59-year-old male with chronic occlusion of the left anterior descending coronary artery underwent a minimally invasive direct coronary artery bypass procedure using the second generation of a magnetic anastomotic coupling device. Postoperative angiogram demonstrated excellent patency and flow.

Anastomosis, Surgical↗

Simplified treatment of postoperative mediastinitis.

BACKGROUND: Wound infection after median sternotomy for cardiac or thoracic surgery is a serious complication. A variety of treatment plans have been advocated, and there is lack of agreement regarding the best treatment method. We present our results in patients with mediastinitis who have been treated in a simple, consistent manner. METHODS: We reviewed our experience with 40 consecutive patients with mediastinitis who were treated between January 1995 and May 2003 with a single-stage treatment consisting of sternal and soft tissue debridement and wound closure over mediastinal tubes with continuous irrigation and drainage. Tubes were placed posterior to the sternum in all patients and were irrigated continuously for at least 7 days with antibiotic or antibacterial solution. Systemic antibiotics were selected based on culture and sensitivity data and were administered for 2 to 6 weeks. RESULTS: All patients with mediastinitis treated in this manner survived. Of the 40 patients, 38 achieved complete healing of the wound without further operative intervention or major complication. One patient had recurrent infection and required sternal resection and advancement of muscle flaps. One patient had a residual localized focus of chondritis and underwent limited resection of cartilage. CONCLUSIONS: In this series of patients with postoperative mediastinitis, a simplified approach consisting of wound debridement, reclosure over drains, and anterior mediastinal irrigation has been an effective treatment. The results we have achieved suggest that this technique may be a suitable option for treating this condition.

Adult↗

Description and evaluation of a ventriculo-coronary artery bypass device that provides bi-directional coronary flow.

OBJECTIVE: The objective of this study was to assess acute patency of a new myocardial revascularization device that connects the left ventricular cavity to a coronary artery (termed ventriculo-coronary artery bypass, VCAB) thereby providing proximal and distal blood flow from the site of the anastomosis. METHODS: A device made of expanded polytetrafluoroethylene and low density polyethylene was implanted from the base of the left ventricle to the mid left anterior descending coronary artery (LAD) in 11 juvenile domestic pigs using a beating heart approach. Flow rates were measured in the distal LAD before and after implant using ultrasonic flow techniques, and patency was assessed at explant at either 2 or 4 weeks post-implantation. Myocardial perfusion using positron emission tomography (PET) was assessed in a separate set of pigs (n=2) revascularized by VCAB 2 weeks post-implant. RESULTS: Net forward flow distal to the implanted device was 73 +/- 15% of native LAD flow. PET demonstrated that the target myocardium was perfused at 85% of that seen in the remote, control myocardium. Device patency rate was 80% (4/5) at 2 weeks in one set of pigs and 83% (5/6) at 4 weeks in a second set of pigs. Histologic analysis showed formation of neointima along the extraventricular segment of the device. CONCLUSIONS: This study demonstrates the promise of perfusing ischemic myocardium using a VCAB approach with a device that provides blood flow both proximal and distal to the anastomosis. Patency of the transmyocardial device was encouraging at 2 and 4 weeks and warrants further investigation.

Animals↗

Clinical and six-month angiographic evaluation of coronary arterial graft interrupted anastomoses by use of a self-closing clip device: a multicenter prospective clinical trial.

OBJECTIVES: To evaluate the safety and effectiveness of a self-closing surgical clip with an interrupted technique in left internal thoracic artery to left anterior descending artery bypass grafting. METHODS: Eighty-two patients were enrolled and treated (February 2000 through August 2001) in a prospective, nonrandomized, multicenter trial. Left internal thoracic artery to left anterior descending artery anastomoses were performed in 60 off-pump coronary artery bypasses (73%), 12 conventional coronary artery bypass grafting (15%), and 10 minimally invasive direct coronary artery bypass (12%) procedures. Angiograms (64 to 383 days, mean 200 days) were obtained on 63 patients (77%). Qualitative and quantitative angiographic assessment was performed by an independent core laboratory. RESULTS: The self-closing surgical clip was used for 82 left internal thoracic artery to left anterior descending artery interrupted anastomoses without the requirement for knot tying or primary suture management. Minimum left internal thoracic artery to left anterior descending artery anastomosis time was 3 minutes. There was one perioperative and one late death (both not heart related) and one reexploration for bleeding unrelated to the anastomotic site. FitzGibbon grades were as follows: A (n = 60, 95.2%), B (n = 3, 4.8%) including one kinked left internal thoracic artery, and O (n = 0, 0%). Quantitative analysis (n = 57) showed mean lumen diameters of left internal thoracic artery proximal to the anastomosis of 2.1 mm, at anastomosis of 2.0 mm, and in the left anterior descending artery distal to the anastomosis of 1.9 mm. The average ratio of the anastomosis to the left anterior descending artery diameter was 1.14 (0.45 to 1.93). Anastomotic stenosis as a percentage of average left internal thoracic artery to left anterior descending artery diameter was -2.3%, comparing favorably with results (23% to 24%) reported from the Patency, Outcomes, Economics, Minimally invasive direct coronary artery (POEM) bypass study. CONCLUSIONS: The interrupted technique, facilitated by a self-closing anastomotic clip, yields favorable 6-month angiographic results when compared with other published studies.

Adult↗

Two cases of anomalous origin of LAD from right coronary artery requiring coronary artery bypass.

We experienced two cases with anomalous origin of the left anterior descending artery (LAD) from the proximal right coronary artery requiring coronary artery bypass grafting. A 66-yr old female with a long history of angina and a positive stress test had the anomalous artery coursing anterior to the right ventricular outflow tract. A 42-yr old male with worsening angina after an anteroseptal myocardial infarction had the anomalous artery running between the great vessels. Both patients underwent left internal mammary artery-to-LAD bypass on the beating heart with complete resolution of ischemic symptoms. Isolated coronary artery anomaly is an uncommon disease (0.6-1.2%) in patients undergoing cardiac catheterization. An anomalous origin of the LAD from the proximal right coronary artery (RCA) or the right sinus of Valsalva (RSV) is very rare, found in 1.2-6.1% of all coronary anomalies. This coronary anomaly has been considered potentially serious but functionally unimportant. We report two cases of anomalous LAD from the proximal RCA resulting in anterior wall ischemia which was effectively treated by coronary artery bypass surgery.

Adult↗

Left ventricular pseudoaneurysm late after mitral valve replacement.

We report an unusual case of left ventricular pseudoaneurysm late after mitral valve replacement. A 60-year-old woman, who had undergone aortic and mitral valve replacement using mechanical prostheses 4 months previously, presented with severe congestive heart failure. The computed tomographic scan of the chest demonstrated a large mass displacing the heart anteriorly. The orifice of the pseudoaneurysm was successfully closed on the beating heart using partial femorofemoral bypass through a left thoracotomy.

Aneurysm, False↗

Short- and long-term results of open heart surgery in patients with abdominal solid organ transplant.

OBJECTIVES: Cardiac disease is a common cause of mortality and morbidity in patients with abdominal solid organ transplant. Improvement of the results of abdominal organ transplantation has contributed to an increasing pool of patients who require open heart surgery. We investigated short- and long-term results of open heart surgery in patients with functioning abdominal solid organ transplants. METHODS: We retrospectively examined 60 patients (52.5 years in average) undergoing coronary artery bypass grafting and/or valve surgery since July 1988 after abdominal organ transplantation. There were 22 females (37%). They consisted of 46 kidney, nine kidney-pancreas and five liver recipients. Cardiac surgery was performed 68.9 months after transplantation. Preoperative serum creatinine level was 2.1 mg/dl, and 11 patients (18%) had creatinine level more than 3.0 mg/dl. Eleven patients (18%) were operated upon on non-elective basis. Twelve patients (20%) were not given stress-dose steroids postoperatively. RESULTS: Three patients died early after surgery (5.0%). Twenty-six major complications were seen in 17 patients (28%), including deterioration of renal function in seven (three patients required temporary hemodialysis), three major infections, two bleeding complications, and two strokes. No graft loss was encountered. No differences were seen in mortality and morbidity between patients with or without stress-dose steroids. Multivariate analysis identified cardiopulmonary bypass time (P<0.05) as a risk factor for operative death, preoperative creatinine level (P<0.05), cardiopulmonary bypass time (P<0.05) and the amount of fresh frozen plasma used (P<0.05) for major complication, non-elective surgery (P<0.01) for deterioration of renal function. Thirteen patients died and five kidney allografts failed late after surgery. Three- and 5-year patient and graft survivals were 70.8 and 66.8, 84.5 and 84.5%, respectively. Multivariate regression analysis identified female gender (P<0.05), body mass index (P<0.001) and non-elective surgery (P<0.001) as risk factors for late death, and preoperative creatinine level (P<0.05) for late graft loss. CONCLUSIONS: Open heart surgery can be performed with acceptable short- and long-term results in patients with functioning abdominal transplants. Stress-dose steroid may be unnecessary in selected patients. Aggressive use of open heart surgery in this patient population to avoid non-elective surgery may further improve early and late surgical outcomes.

Adult↗

Early experience of coronary artery bypass grafting with a new self-closing clip device.

OBJECTIVE: We are in the midst of development of several new anastomotic devices for use in coronary artery bypass grafting surgery. This study was designed to examine one of these devices (a new self-closing clip) for left internal thoracic artery-left anterior descending coronary artery anastomosis. Its feasibility and the quality of anastomosis were evaluated. METHODS: Fourteen patients who underwent first-time elective coronary artery bypass surgery were enrolled between July and December 2000. The left internal thoracic artery was anastomosed to the left anterior descending coronary artery in an interrupted manner with Coalescent U-clips (Coalescent Surgical, Inc, Sunnyvale, Calif). Immediate patency was checked with a transit-time flowmeter. Selective angiography was performed 6 months after surgical intervention. RESULTS: Five patients underwent on-pump coronary bypass grafting, 9 on the beating heart. One patient was excluded from the study intraoperatively because of a poor target site necessitating a 2-cm-long anastomosis. Left internal thoracic artery-left anterior descending artery anastomoses were created with an average of 11.8 clips in 15.9 minutes. Mean graft flow was 45.6 mL/min. Neither conversion to standard suture technique nor revision of anastomosis was necessary. There tended to be a learning curve in the anastomosis on the beating heart. Postoperative lengths of stay in the intensive care unit and the hospital were 20.7 hours and 3.9 days, respectively. Neither death nor major complication was seen, except for temporary atrial fibrillation in 2 patients. Graft patency at 6 months was 100% (FitzGibbon grade A). CONCLUSION: Left internal thoracic artery-left anterior descending artery anastomoses can be created safely and effectively with new self-closing clips on the beating, as well as the arrested, heart. Midterm patency was shown to be perfect by means of angiography.

Adult↗

Surgical ablation of atrial fibrillation.

Surgical ablation of atrial fibrillation (AF) is the most effective means of curing this arrhythmia, with the classic Maze procedure eliminating AF in more than 90% of patients. A complex but safe operation, the Maze procedure has been applied by relatively few surgeons. However, recent advances in the understanding of the pathogenesis of AF and development of new ablation technologies enable surgeons to perform pulmonary vein ablation, create linear left atrial lesions, and remove the left atrial appendage rapidly and safely. Lesions are created under direct vision, minimizing the risk of damage to the pulmonary veins and adjacent mediastinal structures. Most surgical ablation procedures have been performed in conjunction with mitral valve surgery, the combination of mitral valve repair and cure of AF enabling patients to avoid lifelong anticoagulation. Recently developed surgical instrumentation now enables thoracoscopic and keyhole approaches, facilitating extension of epicardial AF ablation and excision of the left atrial appendage to patients with isolated AF and no other indication for cardiac surgery.

Atrial Appendage↗