Extracorporeal membrane oxygenation support improves survival of patients with severe Hantavirus cardiopulmonary syndrome.

OBJECTIVE: The purposes of this study are to evaluate the outcome of extracorporeal membrane oxygenation support in a subgroup of patients with Hantavirus cardiopulmonary syndrome who had a predicted mortality of 100% and to assess the complications associated with this treatment modality and with different cannulation techniques. METHODS: Thirty-eight patients with severe Hantavirus cardiopulmonary syndrome were supported with extracorporeal membrane oxygenation between April 1994 and June 2006. Cannulation of the femoral vessels was performed on an emergency basis by a percutaneous approach in 15 (39.5%) and by an open technique in 23 (60.5%) patients. Duration of extracorporeal membrane oxygenation averaged 132 hours (range: 5-276 hours). RESULTS: Complications from percutaneous cannulation occurred in 4 (26.6%) of 15 patients: retroperitoneal hematoma in 2 (13.3%) and lower extremity ischemia in 2 (13.3%) patients, which resolved after insertion of a distal perfusion cannula. Complications from open femoral cannulation occurred in 8 (34.8%) of 23 patients: severe bleeding in 7 (30.4%) patients and lower extremity ischemia in 1 (4.3%) patient who required a leg amputation. The overall survival was 60.5% (23/38 patients). Six (40%) of the 15 patients cannulated percutaneously and 9 (39.1%) of 23 patients who had open cannulation died. All survivors recovered completely and were discharged from the hospital after a mean hospital stay of 20.8 days (range: 10-39 days). CONCLUSIONS: Almost two thirds of the patients with severe Hantavirus cardiopulmonary syndrome who were supported with extracorporeal circulation survived and recovered completely. The complications associated with both types of femoral cannulation may be attributed to the fact that all patients were in shock or in full cardiac arrest, and the procedure had to be done expeditiously. Earlier institution of extracorporeal membrane oxygenation may decrease the complication rates and improve the overall survival.

Off-pump coronary artery grafting in patients with left main coronary artery disease.

BACKGROUND: Left main coronary artery disease (LMCD) is considered a relative contraindication to off-pump coronary artery bypass (OPCAB) grafting. This study evaluates the safety and feasibility of OPCAB in these patients compared to an on-pump group (cardiopulmonary bypass, CPB) with LMCD. METHODS: Between January 2000 and July 2002, 95 patients with left main coronary artery stenosis >50% underwent coronary revascularization. Seventy-three unselected patients underwent OPCAB and 22 underwent revascularization using CPB. The techniques used for OPCAB included the use of deep traction sutures in the posterior pericardium and stabilizers to expose the distal coronary targets. Intraluminal coronary shunts were routinely used during construction of the anastomoses. Variables were analyzed using a Student's paired t-test with statistical significance defined as p < 0.05. RESULTS: The mean age in the OPCAB group was 59.9 years and the CPB group 61.8 years (p = 0.54). There were 56 males (77%) in the OPCAB and 18 (82%) in the CPB groups. Mean preoperative left ventricular ejection fraction (LVEF) was 40.3% in OPCAB and 47.3% in CPB (p = 0.015). Average number of grafts was 3.1 in OPCAB and 4.1 in CPB (p = 0.0038). There were no conversions to CPB in those patients initially chosen to undergo OPCAB. There were no early deaths in OPCAB. There was one death in CPB. Mean hospital length of stay was 6.9 days for OPCAB and 9.1 for CPB (p = 0.0159). CONCLUSIONS: Patients with LMCD can undergo OPCAB grafting safely and effectively despite reduced LVEF. LMCD should no longer be seen as a contraindication to perform OPCAB grafting.

Beating-heart valve surgery in patients with renal failure requiring hemodialysis.

BACKGROUND AND AIM OF THE STUDY: The safety and efficacy of beating-heart valve surgery as a myocardial protection strategy was evaluated in patients with renal failure requiring hemodialysis. METHODS: This was a retrospective review of nine patients (four males, five females; mean age 46.7 years; mean duration of hemodialysis 47 +/- 49 months) who underwent beating-heart valve surgery at the present authors' institution between April 2000 and September 2002. RESULTS: The mean cardiopulmonary bypass time was 77.2 +/- 8 min. Perioperatively, two patients died (one from sepsis; one from complication of anticoagulation). There were no deaths in the follow up since discharge, with average follow up 18.3 months (range: 9-27 months). Other complications included reintubation for <24 h (one case), AV graft thrombosis (one patient) and stroke (one patient, as mentioned above). There were no new cardiac (including arrhythmia and low cardiac output syndrome) or metabolic complications (including hyperkalemia and fluid overload). CONCLUSION: This is the first report of beating-heart valve surgery using simultaneous antegrade and retrograde perfusion with normothermic blood. Despite being small in size, the study demonstrated the safety of this approach in a high-risk population with renal failure requiring hemodialysis. The results suggested a low incidence of complications, and short ICU and hospital stays.

Redo-OPCAB via left thoracotomy using symmetry aortic connector system: a report of two cases.

Left thoracotomy is an established approach for redo coronary artery bypass grafting (CABG). This approach has also been successfully used in off-pump coronary artery bypass (OPCAB). Traditionally, the grafts have been anastomosed proximally to the descending thoracic aorta or the left subclavian artery. Recently, proximal connectors have been introduced by various manufacturers for use on ascending aorta during primary CABG and OPCAB. One such device is the Symmetry aortic connector system (St. Jude Medical, Minneapolis, MN). These devices have obviated the need for partial occluding clamps for the construction of the proximal anastomoses and hence are extremely useful when the aorta is heavily calcified. We used this device successfully in two patients undergoing redo-OPCAB, where the proximal anastomosis was constructed on the descending aorta. In so doing, we also used the shortest possible length of vein graft since the descending aorta at that level was much closer than the left subclavian artery. This can be an additional factor in redo-operations where the availability of vein can be an issue.

Initial experience with sutureless proximal anastomoses performed with a mechanical connector leading to clampless off-pump coronary artery bypass surgery.

BACKGROUND: We report our early experience with the Symmetry Aortic Connector (St. Jude Medical, St. Paul, MN) used for sutureless proximal aortosaphenous vein graft anastomoses without any cross clamp during coronary bypass procedures. METHODS: Between November 2001 and August 2002, 206 saphenous vein to aorta proximal anastomoses were created in 132 patients using the Symmetry device. All procedures were performed as part of off-pump coronary artery bypass surgery without any aortic clamping. Intraoperative variables and postoperative data were collected and analyzed retrospectively. RESULTS: All 206 anastomoses (100%) were successfully completed with the connector. Severe atherosclerotic disease of the aorta was documented in 16 patients (12%). Four anastomoses (2%) required additional suture placement. Predeployment problems occurred with 3 grafts (2.5%) during loading of the connector. Average number of distal bypasses was 3.2 per patient. One patient (0.7%) required reoperation for bleeding from a proximal anastomosis. Six patients (4.5%) had perioperative myocardial infarction documented by electrocardiographic changes. Thirty-day operative mortality was 3% (4 patients). Intraoperative transit time flow measurement was performed in all cases (100%). Postoperative angiography in 43 patients at a median 3 months postoperatively revealed occlusion of 9 of the 81 saphenous vein grafts (11%). CONCLUSIONS: The initial experience with a proximal saphenous vein graft to aorta anastomosis using the Symmetry connector demonstrates safety and ease of use. There is however some concern with early graft closure. A prospective randomized study is needed to clarify these concerns.