Balloon mitral valvotomy by using the Twin-AT catheter: immediate results and complications in 110 patients

Brain "embolism" detected by magnetic resonance imaging during percutaneous mitral balloon commissurotomy

PURPOSE

The common finding of thrombi between the bifoil balloons when they were extracted after mitral dilation prompted us to look for evidence of minor brain embolisms using the sensitive technique of BMRI (brain magnetic resonance T2-weighted imaging).

METHODS

BMRI was performed within 48 hr before and after a percutaneous mitral balloon commissurotomy (PMBC) in each of the 63 patients in this study.

RESULTS

There was evidence (hyperintensity foci: HI) of a previous asymptomatic brain embolism in 38 of 63 patients before PMBC and a new HI appeared in 18 of 63 patients after the procedure. New HI signals were found exclusively in the white matter in 8 of 18 patients and in only 3 of 18 were HI signs larger than 1 cm. One patient, with an HI signal > 1 cm in the thalamus and another < 1 cm in the brain stem, presented diplopia accompanied by other minor clinical signs. The differences in HI rate among four subgroups (1, older vs younger than 43 years; 2, sinus rhythm vs atrial fibrillation; 3, echo score < 8 vs > 8; 4, patients from western countries vs the others) were not statistically significant, probably because the number of patients in each subgroup was low. Patients in atrial fibrillation had slightly more (not significant) HI before PMBC (15/20, 75%) than patients in sinus rhythm (23/43, 53%), but after PMBC their HI frequencies were similar (atrial fibrillation: 5/20, 25%; sinus rhythm: 13/43, 30%).

CONCLUSION

Brain microembolism is frequent during PMBC, but is often anatomically limited and free from clinical signs in most cases. Brain embolism seems to be related mainly to the procedure itself and not the features of the patient.

Transjugular approach to transseptal balloon mitral valvuloplasty

The feasibility of a transjugular approach to septal puncture and Inoue-balloon mitral valvuloplasty (BMV) was studied in 20 patients with severe mitral stenosis and varying degrees of anatomic atrial distortion. Left atrial entry by transjugular septal puncture was achieved without difficulty and BMV completed in all patients. In all of 16 patients who had high septal punctures, crossing the mitral valve with the Inoue-balloon was consistently simple and quick. In one patient, septal dilation after very high septal puncture led to a tear extending to the atrial free wall, resulting in cardiac tamponade requiring surgery. Another patient developed severe mitral regurgitation after BMV and required mitral valve replacement. Excellent results were obtained in 16 patients. The transjugular approach simplifies BMV procedure significantly in patients with distorted atrial anatomy and allows rapid patient mobilization. Its safety and efficacy need to be established in larger studies.

Percutaneous balloon mitral valvuloplasty

Percutaneous balloon mitral valvuloplasty, first performed by Inoue in 1982, was a rational progression from 4 decades of experience with the blunt surgical dilatation technique of closed mitral commissurotomy. As with surgical commissurotomy, balloon valvuloplasty relieves mitral stenosis by the splitting of fused commissures. A series of studies have shown that balloon valvuloplasty achieves excellent acute hemodynamic results in close to 90% of patients, with a typical 100% increase in mitral valve area. Over the past 15 years since Inoue's first patient, a number of other techniques have been introduced and largely discarded in favor of the original approach. Advances have occurred along the lines of improved noninvasive assessment of mitral valve disease, which have allowed better case selection and prediction of outcome. Follow-up series have shown sustained improvement, with modest rates of complications and restenosis. Comparative studies have shown that balloon valvuloplasty is as effective and safe as surgical commissurotomy, and is a cost-effective procedure of first choice in ideal patients.

Mitral dilatation with the Multi-Track system: an alternative approach

We developed a simple and versatile new technique (Multi-Track) for percutaneous mitral valvotomy using two two separate balloon catheters positioned on a single guidewire. The first catheter, with only a distal guidewire lumen and a proximal balloon, is introduced over the guidewire into the vein and then advanced into the mitral valve orifice. Subsequently, a normal balloon catheter running on the same guidewire is inserted and lined up with the first catheter so the two are positioned side by side. The balloons are then inflated simultaneously. The technique was applied in 12 patients between 10 and 44 years of age (mean, 27.1) and weighing 24-80 kg (mean, 50.3). Valve area increased from 0.66 cm2 (range, 0.3-0.9 cm2) to 1.97 cm2 (range, 1.3-3.1 cm2) and mean left atrial pressure dropped from 31 mmHg (range, 18-52 mmHg) to 12 mmHg (range, 5-22 mmHg). Mitral dilatation with the Multi-Track system gives results comparable to those with previously described techniques and uses simpler and less costly catheters.

Controversies in balloon mitral valvuloplasty: the when (timing for intervention), what (choice of valve), and how (selection of technique)

Despite the established role of percutaneous balloon mitral valvuloplasty (BMV) in the treatment of mitral stenosis, major controversial issues in the realm of BMV persist. With increased operator experience, BMV has now been extended to include various controversial scenarios, such as mild mitral stenosis, adverse valve morphologies, and high-risk patients with concomitant anatomic distortions which are technically demanding. In skilled hands, however, BMV has yielded a favorable outcome in these settings. Furthermore, the debate on whether the Inoue or the double-balloon approach is superior continues. Studies to date have shown equal efficacy of the two BMV methods in terms of valve enlargement although the Inoue approach is clearly simpler to execute and may potentially be associated with a lower risk of creating severe mitral regurgitation. Last, because of the lack of consensus on optimal balloon sizing for BMV, perhaps the best method to adopt at this stage is one that is simple and safe to apply across a broad spectrum of valve anatomy.