BALLOON MITRAL VALVOTOMY - COMPARISON BETWEEN ANTEGRADE INOUE AND RETROGRADE NON-TRANSSEPTAL TECHNIQUES

Aims The results of percutaneous mitral valvotomy performed by the ant egrade transseptal method using the Inoue balloon (n = 1000; group 1) and by the retrograde non-transseptal technique using a polyethylene b alloon (n = 100; group 2) were compared in a retrospective, non-random ized study. Methods and results Both the groups were similar with resp ect to baseline characteristics. The success rate was 95% in group 1 a nd 93% in group 2. There was a significant increase in mitral valve ar ea estimated by Gorlin's equation (Group 1: from 0.8 +/- 0.5 to 2.1 +/ - 0.8 cm(2); Group 2: from 0.8 +/- 0.3 to 1.9 +/- 0.8 cm(2), both P < 0.001) and by Doppler echocardiography using the pressure half-time me thod (Group 1: from 0.9 +/- 0.4 to 2.2 +/- 0.6 cm(2); Group 2: from 0. 9 +/- 0.3 to 2.0 +/- 0.7 cm(2), both P < 0.001). However, the calculat ed immediate post-valvotomy mitral valve area was larger with the Inou e technique (2.1 +/- 0.8 vs 1.9 +/- 0.8 cm(2); P < 0.02). Results were considered optimal when the mitral valve area increased to greater th an or equal to 1.5 cm(2), the percentage increase was greater than or equal to 50, and mitral regurgitation was less than or equal to 2/4. O ut of the total successful procedures, optimal results were obtained i n 95% patients in Group 1 and 94% in Group 2. Incidence of significant mitral regurgitation (greater than or equal to grade 3/4) was similar in two groups (Group 1: 4% vs Group 2: 5%, P = ns). A significant lef t to right atrial shunt (Qp/Qs greater than or equal to 1.5:1) in 2.5% and tamponade in 2% of cases occurred exclusively with the Inoue tech nique, while conduction disturbances, such as transient (< 24h) left b undle branch block (28%) and complete heart block (2%) were noted with the retrograde technique (Group 2). Local complications were signific antly higher in Group 2 (3% vs 0.5%, P < 0.01). The procedure time wit h the Inoue technique was shorter than with the retrograde (Group 1: 1 5 +/- 8, range 10 to 35 min; Group 2: 22 +/- 14, range 15 to 45 min, P = 0.05). Echocardiographic follow-up at 1 year showed no significant difference in mitral valve area between the two groups (Group 1 (n = 3 00): 1.8 +/- 0.8 vs Group 2 (n = 60): 1.9 +/- 0.9 cm(2); P = 0.3). Con clusions Balloon mitral valvotomy using the Inoue balloon and the retr ograde non-transseptal technique results in significant immediate haem odynamic and symptomatic improvement. The Inoue technique achieved a l arger immediate post-valvotomy mitral valve area, but the difference w as not apparent at 1 year follow-up. Incidence of significant mitral r egurgitation was similar with both the techniques; however, local comp lications occurred more frequently with the retrograde technique. Both techniques may complement each other in technically difficult cases.