Left superior vena cava to the left atrium: do we have to change the traditional approach?

Left superior vena cava (LSVC) to the left atrium is a rare congenital cardiac complex, which may appear as an isolated anomaly, or as part of more complex cardiac anomalies. Traditionally, an intraatrial baffle was the preferred surgical technique. Although this technique has proved reliable and successful, acute ligation and extracardiac repair are simpler and easier solutions, requiring less myocardial ischemic time. We present 3 patients who underwent simple ligation and discuss the literature for other extracardiac options of surgical repair. Our patients had short transient congestion in the left upper part of their body that resolved completely after a few weeks, without further complications. We believe that either acute ligation or extracardiac repair is a much simpler yet effective solution to divert the left caval flow to the lesser circulation.

Isolated left superior vena cava to the left atrium with situs solitus and dextrocardia: extracardiac repair facilitated by juxtaposition of the atrial appendages.

We describe an extremely unusual case, with isolated left superior vena cava to the left atrium, normal intracardiac anatomy, and left juxtaposition of the atrial appendages. Surgical repair was performed without cardiopulmonary bypass by anastomosing the left superior cava to the superior aspect of the right atrial appendage, and was facilitated by the ectopic location of the appendage.

Controlled periadventitial administration of verapamil inhibits neointimal smooth muscle cell proliferation and ameliorates vasomotor abnormalities in experimental vein bypass grafts.

OBJECTIVE: Inhibition of early myointimal proliferation may improve longterm patency of vein grafts, but the clinical use of many experimental drugs is limited by systemic toxicity. To determine whether this goal can be achieved by low-dose targeted drug administration, we constructed a polymeric system delivering verapamil and evaluated the effects on local and downstream vein graft morphology, neointimal smooth muscle cell proliferation, and vasomotor function. METHODS: Ethylene-vinyl acetate polymeric delivery systems were constructed, containing 2% verapamil by weight. These are flexible, biocompatible, and nonbiodegradable matrices, delivering the drug at a rate of 10 micrograms/day. The autologous external jugular vein was used to create a carotid artery bypass graft in hypercholesterolemic (n = 22) rabbits. Verapamil-containing matrices (n = 12) or plain polymers (control, n = 10) were wrapped around the proximal third of the veins after reperfusion. Graft vasomotor function was evaluated and was also compared with function of an additional group of normocholesterolemic vein grafts (n = 8). RESULTS: Twenty-eight days after grafting, intimal index (intima/media thickness ratio) was 31% lower, neointima/original lumen surface ratio was 26% lower, and residual luminal area was 71% greater (4.00 +/- 1.2 mm2 versus 2.34 +/- 0.9 mm2, all p < 0.01) under verapamil matrices compared with control grafts. Neointimal smooth muscle cell content was reduced from 45.4% to 28.2%, and net neointimal smooth muscle cell thickness was reduced by 47% (30 microns vs 15.8 microns, both p < 0.01). Verapamil-treated segments distal to the matrices also showed significantly lower neointimal smooth muscle cell density and increased lumen size. Sensitivity to serotoin and vasomotor responses to serotonin, norepinephrine, and sodium nitroprusside in distal segments were significantly lower in verapamil-treated grafts than in controls. CONCLUSIONS: Periadventitial controlled administration of verapamil below 1% of the systemic dose effectively inhibits myointimal hyperplasia in vein grafts. Local polymeric drug delivery may be readily applicable to coronary revascularization operations.

Controlled delivery of a tyrphostin inhibits intimal hyperplasia in a rat carotid artery injury model.

We examined the inhibitory effect of AG-17, a potent inhibitor of protein tyrosine kinase activity on injury-induced vascular SMC proliferation by polymeric-based, periadventitial controlled release implant in the balloon catheter carotid injury model in rats. The AG-17 delivery system was formulated from ethylenevinyl acetate copolymer and the release kinetics as well as drug stability were determined. Polymeric matrices containing 2 or 10% AG-17 were implanted perivascularly in rats following balloon catheter injury. Western blot analysis of explanted arterial segments revealed enhanced tyrosine phosphorylation in injured arteries that was essentially reduced to normal levels in treated arteries. The mean neointima to media ratios were significantly reduced in both 2% (0.79 +/- 0.17, n = 9, P < 0.02) and 10% AG-17 (0.59 +/- 0.09, n = 12, P < 0.001) groups in comparison to the control group (1.38 +/- 0.18, n = 16). The mean areas of the media in the control and the 2% AG-17 group did not differ significantly but a significant reduction of the mean area of the media was observed in 10% AG-17 group. Embedding of the unstable tyrphostin compound, AG-17, in a hydrophobic matrix stabilizes the drug both in vitro and in vivo, and allows delivery-rate modulation as well as protracted site-specific therapy. Perivascular controlled release delivery of the tyrphostin AG-17 inhibits neointimal formation in the rat carotid injury model.

Autologous monocusp pulmonary valve: preliminary results.

BACKGROUND: There is growing recognition that postoperative pulmonary regurgitation may result in early or late progressive right heart failure. METHOD: A technique for fashioning an autologous monocusp pulmonary valve from the wall of the pulmonary artery was developed. The monocusp valve was fashioned from the anterior wall of the main pulmonary artery, and the remaining defect was filled with autologous pericardium. The procedure was performed in 8 dogs and 5 children. RESULTS: Early follow-up and serial echocardiographic assessment in both dogs and children proved the functionality of this monocusp pulmonary valve. All valves were pliable and demonstrated mild to moderate pulmonary stenosis and insufficiency. CONCLUSIONS: Construction of the autologous monocusp pulmonary valve is a feasible technique, and the valve performs efficiently. The acute performance in the canine model was excellent, and preliminary midterm results in the clinical study are reasonable. It is logical to assume that the monocusp, being an integral part of the arterial wall, will retain its viability and share in the subsequent growth of the pulmonary artery. Should follow-up studies demonstrate its long-term competence, this autologous valve may provide a good solution for various forms of pulmonary regurgitation and be useful in pulmonary autograft replacement of the aortic valve.

Interruption of right sided aortic arch. Case report and review of the literature.

Interrupted right sided aortic arch is a very rare anomaly, and to our knowledge only one such case in which the patient underwent complete repair has been recorded in the literature. Twelve additional cases were found on autopsy or underwent palliative surgery. We present the case of a 25-day-old infant with an interrupted right sided aortic arch. The anomaly was repaired by a one-stage surgical approach, and the patient discharged from the hospital. Surgical technique considerations are discussed.

Repair of internal carotid aneurysm under local anaesthesia. Case report.

Aneurysms of the extracranial carotid arteries are unusual events but cause death or a cerebrovascular accident in the majority of cases (50-70%). This report describes a true internal carotid artery aneurysm that developed within six weeks. The aneurysm was resected and the artery repaired by the use of a graft from the internal jugular vein. Carotid cross-clamping time was 93 minutes. The operation was performed under local anaesthesia, with continuous clinical monitoring of the ipsilateral cerebral hemisphere function.