Cardiac surgery and plasma digoxin levels.

Cardiopulmonary bypass (CPB) can induce several haemodynamic alterations and therefore influence pharmacokinetics of various drugs. In order to assess the effect of CPB on plasma digoxin levels, these were monitored in patients undergoing open heart surgery involving CPB (n = 11), over a 24 hour period, starting just prior to commencement of surgery. For comparison, plasma digoxin was also monitored in a group of patients (n = 10) who underwent cardiac surgery not involving CPB. In 7 of the 11 patients in the CPB group, plasma digoxin levels (ng/ml) were significantly (p < 0.01) lower at the end of 24 hours (0.654 +/- 0.094) than basal levels (1.3114 +/- 0.2498). In contrast, in the non CPB group, 7 of 10 patients showed significantly higher (p < 0.001) plasma levels (ng/ml) at the end of 24 hours (0.477 +/- 0.125) as compared to basal levels (0.26 +/- 0.098). Thus, rather than the type of surgery, it appears that the pre-operative levels of plasma digoxin influence its pharmacokinetics.

Enhancement of haemopoietic stem cell adherence to bone-marrow derived stroma by phyto-haemagglutinin treated leucocyte conditioned medium (PHA-LCM).

Stem cell adhesion to bone-marrow derived stroma, plays a crucial role in haemopoiesis. However, there is very little information as to the nature of the adhesion molecule. In this paper we have shown that human bone-marrow derived stroma can be established in tissue culture. This stroma is able to adhere human bone-marrow mononuclear cells including the multipotent stem cell, viz. CFU-GEMM. Their adherence increases when the stroma is treated with lymphokines in the form of PHA-treated leucocyte conditioned medium (PHA-LCM). Triton X-100 extracts of the untreated and PHA-LCM treated stroma were analysed on single dimension PAGE. It was observed that PHA-LCM treated stromal extracts showed two extra bands and an increase in the density of a band of approximately 14 kDa. Whether these changes have anything to do with the increased adhesion of stem cell is not yet known.

Surgical correction of aneurysms of sinus of Valsalva--a report of 22 cases.

Twenty two cases of aneurysm of sinus of Valsalva managed during a 12 year period are analysed. The right coronary sinus was involved in 14 and the non-coronary sinus in eight cases. It had ruptured in 20 patients while in the other two it had produced right ventricular outflow tract (RVOT) obstruction. Six patients had associated ventricular septal defect (VSD), and eight had aortic regurgitation (AR), five of these requiring aortic valve replacement (AVR). Aortocameral approach was preferred and was used in 18 patients. Recurrence had occurred in one. Surgical management and results are discussed.

Temporary intravascular shunts for peripheral vascular trauma.

Polyvinylchloride (PVC) disposable endotracheal suction catheters were successfully used as temporary intravascular shunts in 5 patients of popliteal artery trauma. These simple shunts should be used routinely in such conditions to immediately re-establish blood supply to the ischaemic limb particularly in patients of polytrauma where systemic anticoagulation is contraindicated. This avoids the inherent delay prior to vascular repair and reduces the incidence of irreversible ischemia.

Surgical management of tetralogy of Fallot with anomalous coronary artery.

Fifteen patients of tetralogy of Fallot with an anomalous left anterior descending coronary artery arising from the right coronary artery were operated during a period of 1982 and 1988. One patient died in the early post-operative period (6.6%). Two patients had a hemodynamically insignificant residual ventricular septal defect. Post-operative peak systolic pressure gradient between the right ventricle and pulmonary artery ranged from 10 mm Hg to 40 mm Hg (mean 24 mm Hg) in 4 patients. There was no incidence of inadvertent coronary artery division.

Repeat open intracardiac operation--analysis of 55 patients.

Of the 4170 open intracardiac operations performed at our hospital in the last 6 years, 55 (1.3%) were reoperations. Of these failed valve repairs or valve substitutes formed the major group (58%) and the interval between first and second operation ranged from 6 months to 8 years. There were 4 deaths on table and another 6 patients died during their hospital stay giving an early mortality rate of 18 per cent. There was one late death during a follow-up period of 1 month to 3 years. There was no death due to perioperative bleeding complications. We conclude that it should now be possible to perform reoperations with an acceptable mortality and good late functional results.