Management of extracorporeal circulation in heart surgery through a right mini-thoracotomy

Objectives

Minimally invasive open heart surgery requires cardiopulmonary bypass (CPB) to be initiated via peripheral access. We report our initial experience with a modified femoro-femoral CPB, with the superior vena cava being drained by a supplementary cannula inserted via the jugular vein. However, because of smaller diameter of the cannula, a slight modification to the CPB was necessary to improve the impeded venous return.

Methods

Cannulation of the superior vena cava was performed through the right jugular vein during maintenance of anesthesia. After right mini-thoracotomy and exposure of the femoral site, CPB was initiated by cannulation of the femoral artery, and the inferior vena cava via the femoral vein using the Heartport^® system. A modified open CPB system (Jostra^®) was used. In order to improve the venous return, the venous reservoir was completed with a device offering undertow, which was monitored by a low pressure valve in the venous and a vacuum controller in the arterial line. Myocardial protection was performed using Bretschneider's solution. A minimal (7–9 cm) right thoracotomy through the fourth intercostal space was used in all cases as the surgical approach. All procedures were performed video-assisted.

Results

During our initial experience between April and October 2002, seven patients were operated on using this technique (five males/two females; age 52.6 ± 9.5 years; body weight 78.7 ± 19.4 kg; body surface area 1.94 ± 0.3 m²). Five patients were operated on for mitral valve repair/replacement and two patients for closure of an atrial septal defect. Cannula sizes were 18–20 Fr for the femoral artery, 25 Fr for the femoral vein and 16 Fr for the superior vena cava. Considering the theoretical perfusion flow of 5.5 l/min, the venous flow through both cannulae was 4.27 ± 0.5 l/min. Mean CPB and cross-clamp times were 141.7 ± 38.6 min and 87.5 ± 24.5 min, respectively. Minimum venous saturation was 97.4 ± 1.8 %. There were no cases of hospital or late postoperative mortality. No case of postoperative adverse events occurred. All patients were extubated within 8 hours postoperatively and were discharged from the intensive care unit by the first postoperative day.

Conclusions

Despite our limited initial experience, and considering the smaller internal diameter of percutaneous cardiopulmonary bypass cannulae as compared with the classic one, the modifications to the CPB system we used in this study improved venous drainage significantly, so that minimally invasive open heart procedures could be performed under optimal CPB conditions in our center.