Najib Al-Khaja

Eleven years' experience with Carpentier-Edwards biological valves in relation to survival and complications.

The Carpentier-Edwards porcine valve bioprosthesis was implanted in 299 patients (325 prostheses) from April 1976 to April 1982. The series consisted of aortic valve replacement in 150 patients, mitral valve replacement in 120, multiple valve replacement in 26, pulmonary valve replacement in 2 and tricuspid valve replacement in 1 patient. The postoperative follow-up was 100% complete. The total accumulated follow-up was 1956 patient-years. The early mortality was 6.4% (20 patients) and the late mortality was 22% (62 patients). Valve-related mortality was seen in 8 patients (2.7%): 1 paravalvular leak during the 1st 30 postoperative days and 7 late mortalities (1 endocarditis, 2 paravalvular leaks and 4 deaths during reoperation). Three operative deaths (1.5%) occurred. The overall patient survival including operative deaths was 78.5% +/- 5% at 5 years and 66% +/- 4% at 10 years. The incidence of the different complications were: thromboembolism in 5 patients (1.7%) with a risk of 0.3%, haemorrhage in 1 (0.3%) with a risk of 0.05%, endocarditis in 2 (0.7%) with a risk of 0.1%, and paravalvular leak in 11 patients (3.7%) with a risk of 0.6%. There was a high incidence of tissue failure during the last 6 years which occurred in 54 patients (18%) with a risk of 2.7%. Sixty-seven patients (22.5%) were reoperated upon during the 11 years with an annual risk of 3.4% and the main cause of reoperation was primary tissue failure. The Carpentier-Edwards biological valve was shown to be efficient during the first 5 years of implantation after which the incidence of tissue failure increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up of operative treatment for pulmonary metastases

From 1954 onwards, 132 patients underwent 165 resections for pulmonary metastases. No other forms of therapy were adopted. The operative mortality was 7.6% (10 patients). After a minimum follow-up of 5 years, the overall survival rate was 20%. The 10- and 15-year survival rates were 6% and 3%, respectively. The major cause of late death was recurrence or spread of the primary disease in 102 patients (83.6%) while 5 patients died of reasons not related to cancer. Fifteen patients (12.3%) are still alive, 13 of whom have no clinical cancer. The presence of symptoms, the disease-free interval of less than 1 year and the number of metastases showed a statistically significant detrimental influence on survival (P less than 0.001, P less than 0.05 and P less than 0.046, respectively). The best 5-year survivals of 42%, 24%, 23% and 23% were noted for metastases from malignancies in the body of the uterus, kidney, bone and colon, respectively. Longterm survival or clinical cure can be achieved with surgery alone by an aggressive approach in selected malignancies.

The influence of age on the durability of Carpentier-Edwards biological valves Thirteen years follow-up

Two hundred and ninety-nine patients received 325 Carpentier-Edwards biological valves from April 1976 to April 1982. Valves were placed in the following positions: 150 aortic (AVR), 120 mitral (MVR), 26 multiple (MR), 2 pulmonary (PR) and 1 tricuspid (TR). The mean age was 54.7 years. The total follow-up time was 2545 patient-years. Patients were divided into different age groups: less than 40, 40-49, 50-59, 60-69 and greater than 70 years and were followed-up for reoperations and tissue failure. Ninety-three operations were performed in 91 patients (30.5%) for valve related dysfunctions. The main cause of reoperation was primary tissue failure (85%). The respective incidence and risk of reoperation in the different age groups were 51.5% and 5%, 41.5% and 4%, 32% and 3%, 18% and 2.5%, and 0% for greater than 70 years of age. The risk of reoperation decreased significantly with increasing age (P less than 0.05). The respective incidence and risk of tissue failure in the age groups were 43.8% and 4.1%, 35% and 4%, 27.3% and 3.2%, and 17.2%, 2.4% and 0%. The freedom from reoperation and tissue failure was significantly higher in the older patient (greater than 60 years) compared to the younger patients (less than 60 years). The commonest cause of failure in young patients was calcification, while in older patients it was cusp rupture. Comparing aortic and mitral bioprostheses in the different age groups showed no difference between these valves in patients less than 50 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Does heparin coating improve biocompatibility? A study on complement, blood cells and postoperative morbidity during cardiac surgery

To evaluate whether the effect of heparin coating the extracorporeal circuit resulted in differences in patient outcome and haemostatic alteration, 24 patients undergoing elective, isolated coronary artery bypass were randomized prospectively to cardiopulmonary bypass (CPB) with heparin-coated circuits (group H, n = 12) or uncoated circuits (group C, n = 12). The technique of CPB, heparinization and its reversal were the same in both groups. We studied complement status (C3d, C3, C3d/C3, C4 and C-function), white blood cell counts with differentiation and the postoperative morbidity. The results confirmed that CPB activates complement and increases neutrophils in both the H and C groups. A significantly lower level of Ieucocytosis was seen in group H compared to the C group (p < 0.05). The complement function via the classical pathway (C-function), expressed as a percentage of the function of a reference serum pool (the values of normal sera were 75-125%), was significantly reduced in both heparin-coated and uncoated circuits (p < 0.05). There was no significant intergroup difference regarding C3, C3d/C3, C4 and C-function during the study period. A lower frequency of postoperative morbidity was present in the H group. We conclude that heparin-coated surfaces elicit less leucocytosis and decrease postoperative morbidity in patients undergoing cardiac surgery but do not cause a significant difference regarding activation of the complement system as reported by many other investigators.

Cutaneous microcirculation and blood rheology following cardiopulmonary bypass: laser Doppler flowmetric and blood cell rheologic studies

In 23 patients undergoing coronary artery bypass grafting, measurements of cutaneous blood flow were made with laser doppler flowmetry. Simultaneously blood was sampled for measurement of red cell filtration rate (RFR) and plasma-white cell filtration rate (P-WFR). The cutaneous blood flow showed significant overall reduction postoperatively. When the saphenous vein or internal mammary artery was used as bypass graft, the reduction in skin blood flow at the sites from which the vessels were taken was significantly greater than in contralateral, undisturbed sites. RFR and P-WFR were also significantly reduced postoperatively, and these changes showed significant concomitance with the fall in laser doppler flow (LDF%). On postoperative day 6 there was some improvement in LDF% and RFR but further slight deterioration in P-WFR. The study indicated that surgical trauma locally reduces cutaneous blood flow and that trauma to blood cells following cardiopulmonary bypass can contribute to this reduction.

Reduction of post-thoracotomy pain by cryotherapy of intercostal nerves

In a prospective study, 144 patients undergoing thoracotomy were randomized to two groups: In 71 cases cryoanalgesia was applied intraoperatively to the intercostal nerves above and below the incision to relieve postoperative pain, and 73 (control group) received bupivacaine-adrenaline intercostal blockade at the end of the operation. The amount of administered narcotic and mild analgesics, the visual analogue pain scores, the need for further intercostal blockade and the number of postoperative bronchoscopies to clear retained secretion were significantly less in the cryoanalgesia group than in the controls. There were no late nerve complications after cryoanalgesia, which is recommended for routine use in thoracotomy.

Association between bleeding and reduced red cell deformability following cardiopulmonary bypass

In 56 patients undergoing open-heart surgery, red cell trauma during and following cardiopulmonary bypass (CPB) was monitored with a microfiltration method that estimated deformability of the cells. Red cell deformability was reduced by 38% during CPB and at a slower rate thereafter. The lowest filterability rate was reached on the second day, after which improvement began. In patients who had undergone coronary artery bypass grafting, preoperative values of red cell deformability were reached after 6 weeks. Following valve replacement, however, preoperative values were not regained during this period, which was attributed to continuous mechanical trauma by the artificial valves. A 50% reduction of red cell filterability from the end of CPB to 12 and 24 hours from the start of CPB was associated with heavy blood loss (greater than 1,000 ml) from drains. Reduced red cell deformability thus showed relationship with a bleeding tendency following use of CPB.

The effect of protamine on the epicardial microflow and the graft flow in open-heart surgery:

To evaluate the effect of coronary revascularization on myocardial perfusion and surgical outcome regarding graft flow, we used laser Doppler flowmetry to assess the epicardial microcirculation in patients undergoing coronary artery bypass grafting (CABG) or valve replacement (VR) and electromagnetic flowmetry to measure graft flow in the CABG group. In the CABG group, the preoperative mean laser Doppler flow rate (LDF) in the epicardium of the left ventricle significantly increased at the end of cardiopulmonary bypass (CPB) (22 ± 7 arbitrary units (AU) to 60 ± 13 AU, p < 0.001). This value further increased 10 min after protamine infusion (66 ± 14 AU, p < 0.01), but was significantly reduced 30 min later (51 ± 14 AU, p < 0.002). Compared to the post-CPB value (34 ± 10 ml/min) before protamine infusion, the mean graft flow (ml/min) to this area significantly increased 10 min after protamine infusion (41.3 ± 10 ml/min, p < 0.001) but significantly decreased 30 min later (29 ± 9 ml/min, p < 0.001). The preoperative mean LDF in the VR group was significantly higher than in the CABG group (p < 0.01). In the CABG group, there was a positive correlation between the LDF and graft flow at the end of CPB (r = 0.788) and 10 (r = 0.767) and 30 (r = 0.784) min after protamine infusion. This study shows that coronary bypass grafting increases the myocardial microcirculation which, together with graft flow. could give an early indication of the effect of surgery on myocardial microcirculation. Furthermore, protamine was found to be one of the factors contributing to graft flow reduction postoperatively and, therefore, newer methods of heparin reversal may be desirable.

Association between pulmonary dysfunction and reduced red cell deformability following cardiopulmonary bypass

Fifty-six patients undergoing open-heart surgery were monitored for red cell trauma during cardiopulmonary bypass (CPB), using a standard red cell microfiltration method. The average red cell deformability was reduced by 38%. Respirator time was shorter in the patients with lesser degrees of red cell trauma, and vice versa. After extubation, the tendency to hypercapnia was greatest in the patients with most red cell trauma during CPB. Hypoxic tendencies in the first 24 postextubation hours were comparably distributed among all levels of red cell trauma.

Association between arrhythmias and reduced red cell deformability following cardiopulmonary bypass

In 56 patients undergoing open-heart surgery, trauma to the red cells (reduced deformability) during cardiopulmonary bypass (CPB) was monitored by estimating reduction in red cell filtration rate (RFR). Treatment-requiring arrhythmias (atrial tachyarrhythmia and ventricular tachycardia) appearing more than 24 hours postoperatively were associated with RFR reduction after CPB. The incidence of arrhythmia was 31% in the patients with less than 25% fall in RFR, 53% in those with greater than 25% fall and 81% when the RFR reduction was greater than 75%. RFR fall preceded appearance of arrhythmia.