Discussion
The quest for an ideal conduit to establish RV to PA continuity began in 1964, when Rastelli et al implanted the first valveless pericardial tube in a patient with pulmonary atresia. (4) It was soon realised that competent RVOT has its advantages and Ross et al implanted the first valved conduit in an eight year old boy with VSD pulmonary atresia. (5) This was closely followed by Rastelli et al when two children with transposition of great arteries, VSD and pulmonary stenosis underwent the eponymous Rastelli’s operation. (6) Irradiated cryopreserved aortic homografts were implanted in all three patients. However, the techniques of cryopreservation were crude resulting in rapid degeneration of the homografts. These were replaced by gluteraldehyde preserved porcine aortic valves mounted in Dacron tube grafts. The midterm outcomes of porcine xenografts are acceptable but the failure rate at 10 years as demonstrated by Belli et al was high. (7) The freedom from re-operation following a Hancock conduit was 98%, 81% and 32% at 1, 5 and 10 years respectively. (7) By the mid-1980s, the techniques of cryopreservation process had improved and once again Homografts became the conduit of choice. Though, homografts had several advantages over Dacron mounted xenografts, ease of handling being one of them, limited availability in smaller sizes led to the emergence of another xenograft in the form of bovine Jugular vein (Contegra, Medtronic Inc). (8,9) The bovine Jugular vein has a trileaflet valve and it delivered outcomes comparable to homografts with an added advantage of availability in smaller sizes. (10) A multi-centre European study by Breymann et al involving 165 Contegra implants found that the results were comparable to homografts. (11). Another study by Sandica et al involving 444 consecutive implantation concluded that the bovine jugular veins in RVOT in patients below 25 years had superior outcomes when compared with cryopreserved homografts. (10)
The commercially available options to choose from are pulmonary or aortic homograft, porcine valve in Dacron tube, Porcine valve in bovine pericardial tube and bovine jugular vein. Though, commercially marketed conduits are easily available, high cost precludes its wider use in countries with limited financial resources. The surgeons are often compelled to use conduits prepared in the operating room from e-PTFE, Dacron and autologous or bovine pericardium. (12,13) The early and midterm outcomes of these hand sewn counts have been satisfactory and comparable with the commercially available options. (14,15)
The majority of the published series with hand sewn conduits have used PTFE tube graft for the conduit. Our series is perhaps the first where bovine pericardial sheet is used to construct the conduit. The bovine pericardium is easy to handle and is haemostatic. One of the drawbacks of the bovine pericardial conduit is that it calcifies and forms dense adhesions with the surrounding structures which can complicate the re-operations. The cost of hand sewn BPCTV is $300 which is one-sixth of the cost of commercially available Contegra bovine jugular vein conduit. This cost advantage makes BPCTV an attractive alternative in low resource environments. The early and midterm results of BPCTV in our series were acceptable with freedom from re-intervention of 86% at 30 months.