Amir-Reza Hosseinpour

Surgical technique for heart transplantation: a strategy for congenital heart disease

The standard techniques for orthotopic heart transplantation often require certain adjustments when the procedure is carried out for complex congenital heart disease. This is because of both the unusual anatomy and possible distortions caused by previous surgery. Such technical adjustments have been described in various published reports over the years. Those reports, when combined, do cover the full spectrum of the technical difficulties that may be encountered, whether the defects are in their original form or altered by surgery, such that no cardiac malformation or distortion would prohibit transplantation. However, those reports are comprehensive only when combined. None of the individual reports addresses all the possible technical challenges. Consequently, the available information is somewhat fragmented. In addition, the generic aspect of the described technical strategies is not always given the emphasis that it deserves. Indeed, occasionally a technique may be presented as a specific solution for a specific malformation, without necessarily pointing out that the same technique may be applied to other hearts with different overall pathologies but which share that specific malformation. The aim of this review article was to combine all the available published information in one article in a manner that constructs a simple but comprehensive and generic system of decision-making that may be applied to any heart in order to determine the exact technical adjustments needed for transplantation in each case. Such a strategy is possible for two reasons. First, only a few anatomical sites are technically significant, namely the points of anastomosis between the donors organ and the recipient. The rest of the intracardiac morphology does not affect the operation and may be ignored. Second, each of those anatomical sites can present difficulties in only a few ways, and each of those few difficulties has a well-described and published solution already. Therefore, the exact technical adjustments required in each case may be worked out by the sequential assessment of the anastomotic sites alone.

A simple surgical technique to prevent atrial reentrant tachycardia in surgery for congenital heart disease

OBJECTIVES To present and test a simple surgical technique that may prevent atrial reentrant tachycardia following surgery for congenital heart disease. This arrhythmia is one of the commonest long-term complications of such a surgery. It may occur many years (even decades) after the operation. It is usually explained as a late consequence of right atriotomy, which is an inherent component of many operations for congenital heart disease. Right atriotomy results in a long scar on the right atrial myocardium. This scar, as any scar, is a barrier to electrical conduction, and macro-reentrant circuits may form around it, causing reentrant tachycardia. However, this mechanism may be counterchecked and neutralized by our proposed method, which prevents reentrant circuits around right atriotomy scars. METHODS The proposed method is implemented after termination of cardiopulmonary bypass and tying the venous purse-strings. It consists of constructing a full-thickness suture line on the intact right atrial wall from the inferior vena cava (IVC) (a natural conduction barrier) to the atriotomy incision. This suture line is made to cross the venous cannulation sites if these are on the atrial myocardium (rather than being directly on the venae cavae). Thus, the IVC, atriotomy and cannulation sites are connected to each other in series by a full-thickness suture line on the atrial wall. If this suture line becomes a conduction barrier, it would prevent reentrant circuits around right atrial scars. This was tested in 13 adults by electroanatomical mapping. All 13 patients had previously undergone right atriotomy for atrial septal defect closure: 8 of them with the addition of the proposed preventive suture line (treatment group) and 5 without (control group). RESULTS In all 13 cases, the atriotomy scar was identified as a barrier to electrical conduction with electrophysiological evidence of fibrosis (scarring). In the 8 patients with the proposed suture line, this had also become a scar and a complete conduction barrier. In the 5 patients without this suture line, there was free electrical conduction between the IVC and atriotomy scar. CONCLUSIONS The proposed suture line becomes a scar and conduction barrier. Therefore, it would prevent reentrant circuits around atrial scars and their consequent arrhythmias.

Right atrial thrombosis and pulmonary embolism after atrial septal defect repair

A 3-year-old boy underwent surgical closure of a large ostium secundum atrial septal defect. This was complicated with extensive right atrial thrombus formation and pulmonary thromboembolism immediately following surgery. He was managed with emergency surgical thromboembolectomy and anticoagulation. However, new thrombus was formed again immediately. This prompted us to add thrombolysis to his treatment, but with no effect. He died on the fifth postoperative day. A postmortem study confirmed extensive thromboembolism.

A simple method of aortic valve reconstruction with fixed pericardium in children

Aortic valve reconstruction with fixed pericardium may occasionally be very useful when treating children with aortic valve disease. This is because diseased aortic valves in children are sometimes too dysmorphic for simple repair without the addition of material, their annulus may be too small for a prosthesis, and the Ross operation may be precluded due to other congenital anomalies such as pulmonary valvar or coronary malformations. Such reconstruction is usually technically demanding and requires much precision. We describe a simple alternative method, which we have carried out in 3 patients, aged 1 week, 3 years and 12 years, respectively, with good early results.

Prevalence and prognostic significance of pulmonary artery aneurysms in adults with congenital heart disease

BACKGROUND Prevalence and prognostic significance of pulmonary artery (PA) dilatation in congenital heart disease (CHD) have never been studied systematically. METHODS Chest X-rays of 1192 consecutive adults with CHD were reviewed. Major diameter of the PA was determined by imaging techniques in those with PA dilatation. A value >29 mm was considered abnormal. Data on anatomy, hemodynamics, residual lesions and outcomes were retrospectively collected. RESULTS Overall prevalence of PA dilatation was 18%. A minority of patients (5.5%) reached 40 mm (aneurysm; PAA) and 1.8% exceeded 50 mm. The most common PAA underlying malformations were pulmonary stenosis (21%), and shunts (55%). Significantly larger diameters were observed in hypertensive shunts (40 mm; IQR 36.7-45 mm vs. 34 mm; IQR 32-36 mm) (p < 0.0001). However, the largest diameters were found in cono-truncal anomalies. There was no significant correlation between PA dimensions and systolic pulmonary pressure (r = -0.196), trans-pulmonary gradient (r = -0.203), pulmonary regurgitation (PR) (r = 0.071) or magnitude of shunt (r = 0.137) (p > 0.05 for all). Over follow-up, 1 sudden death (SD) occurred in one Eisenmenger patient. Complications included coronary (3), recurrent laryngeal nerve (1) and airway (1) compressions, progressive PR (1), and PA thrombosis (1). Coronary compression and SD were strongly associated (univariate analysis) with pulmonary hypertension (120 vs. 55 mm Hg; p = 0.002) but not with extreme PA dilatation (range: 40-65 mm). CONCLUSIONS PA dilatation in CHD is common but only a small percentage of patients have PAA. Clinical impact on outcomes is low. Complications occurred almost exclusively in patients with pulmonary hypertension whereas PA diameter alone was not associated with adverse outcomes.

The questionable role of the hybrid procedure

The hybrid procedure was first proposed in 1993, and again in 2002, as an alternative to the Norwood procedure for hypoplastic left heart syndrome, in order to avoid complex cardiac surgery in the neonatal period with all its possible neuro-developmental sequelae [1, 2]. It became popular, however, with the idea that it may prove useful for a subgroup of patients at very high risk of mortality after the Norwood procedure, despite the remarkable reduction in the overall mortality of this operation [3, 4]. These are babies with low weight and/or aortic atresia. The hybrid procedure has been used increasingly for over a decade, without being confined to high-risk cases. Nevertheless, it has failed to show its superiority to the Norwood procedure [5]. This prompted Pizarro et al. to dissect out and define the major risk factors for this procedure, hoping to improve its results by case selection [6]. They show that the two major risk factors for mortality in the Norwood procedure (low weight and aortic atresia) also apply to the hybrid approach, with no survivors when both risk factors coexist. This finding is very important; it makes case selection problematic and paradoxical, since excluding these babies defeats a major purpose of the hybrid procedure. Indeed, case selection here discriminates against the very patients this procedure was hoped to serve. This questions the utility of this approach altogether. For the hybrid procedure to be useful when compared with the Norwood procedure, it must either achieve better neurodevelopmental outcome, or lower overall mortality, or better outcome in high-risk cases. Its neuro-developmental outcome has already disappointed in one study at 1-year follow-up, although more work is needed to clarify this [7]. Lower overall mortality is not achieved [5]. Now, it turns out that it cannot help the high-risk babies either [6]. Furthermore, the hybrid procedure is actually worse than the Norwood procedure in at least one important aspect—distortion of the branch pulmonary arteries by banding, as evidenced by the high rate of reinterventions on these vessels [8–10]. This is a very significant, yet under-emphasized, drawback of the hybrid procedure, since these patients are being prepared for an eventual Fontan which may be jeopardized by pulmonary arterial distortion. So, what does the hybrid procedure offer? It has certainly failed to live up to the original expectations. In addition, its important disadvantage with respect to the risk of pulmonary arterial distortion has been brought to light. However, as Pizarro et al. highlight, it may have found another role as a temporizing measure for cases where an eventual biventricular repair is planned [6]. Although such a temporizing measure may also be achieved with the Norwood procedure, subsequent biventricular repair is shorter and easier (and presumably safer) if the first procedure was the hybrid approach. Also, the concern regarding pulmonary arterial distortion is less significant since a biventricular repair is more forgiving in this respect. This role may turn out to be the main application of this procedure.

Pressure necrosis of the outlet septum caused by two adjacent implants.

A patient had a history of a Ross-Konno procedure, stenting of the pulmonary homograft, and an aortic valve replacement. Pressure necrosis developed in the tissues in between the stent and the prosthetic valve. This resulted in a defect between the right and left ventricular outflow tracts that required a complex operation for its correction.