Balloon mitral valvotomy: comparison between antegrade Inoue and retrograde non-transseptal techniques

AIMS: The results of percutaneous mitral valvotomy performed by theantegrade transseptal method using the Inoue balloon (n=1000;group 1) and by the retrograde non-transseptal technique usinga polyethylene balloon (n=100; group 2) were compared in a retrospective,non-randomized study. METHODS AND RESULTS: Both the groups were similar with respect to baseline characteristics.The success rate was 95% in group 1 and 93% in group 2. Therewas a significant increase in mitral valve area estimated byGorlin's equation (Group 1: from 0·8 ± 0·5to 2·1 ± 0·8 cm²; Group 2: from 0·8± 0·3 to 1·9 ± 0·8 cm², bothP<0·001) and by Doppler echocardiography using thepressure half-time method (Group 1: from 0·9 ±0·4 to 2·2 ± 0·6 cm²; Group 2: from0·9 ± 0·3 to 2·0 ± 0·7cm², both P<0·001). However, the calculated immediatepost-valvotomy mitral valve area was larger with the Inoue technique(2·1 ± 0·8 vs 1·9 ± 0·8cm²; P<0·02). Results were considered optimal whenthe mitral valve area increased to 1·5 cm², the percentageincrease was 50, and mitral regurgitation was 2/4. Out of thetotal successful procedures, optimal results were obtained in95% patients in Group 1 and 94% in Group 2. Incidence of significantmitral regurgitation (grade 3/4) was similar in two groups (Group1: 4% vs Group 2: 5%, P=ns). A significant left to right atrialshunt (Qp/Qs 1·5:1) in 2·5% and tamponade in2% of cases occurred exclusively with the Inoue technique, whileconduction disturbances, such as transient (<24 h) left bundlebranch block (28%) and complete heart block (2%) were notedwith the retrograde technique (Group 2). Local complicationswere significantly higher in Group 2 (3% vs 0·5%, P<0·01).The procedure time with the Inoue technique was shorter thanwith the retrograde (Group 1: 15 ± 8, range 10 to 35min; Group 2: 22 ± 14, range 15 to 45 min, P=0·05).Echocardiographic follow-up at 1 year showed no significantdifference in mitral valve area between the two groups (Group1 (n=300): 1·8 ± 0·8 vs Group 2 (n=60):1·9 ± 0·9 cm²; P=0·3). CONCLUSION: Balloon mitral valvotomy using the Inoue balloon and the retrogradenon-transseptal technique results in significant immediate haemodynamicand symptomatic improvement. The Inoue technique achieved alarger immediate post-valvotomy mitral valve area, but the differencewas not apparent at 1 year follow-up. Incidence of significantmitral regurgitation was similar with both the techniques; however,local complications occurred more frequently with the retrogradetechnique. Both techniques may complement each other in technicallydifficult cases.