Indian Journal of Thoracic and Cardiovascular Surgery 1989-90; 6:84-85

A Modified Tubbs Ventriculotomy-cum-Mitral Valve Dilator AMIT BANERJEE KSVK SUBBARAO M NACHIAPPAN KM MANDANA

ABSTRACT: The usua l t echn ique o f t ransvent r icu la r mi t ra l c o m m i s s u r o t o m y invo lves serial

en l a rgemen t o f an apical left v e n t r i c u l o t o m y w o u n d wi th the he lp o f Hega r di la tors to

faci l i ta te in t roduc t ion o f a Tubbs di la tor w h i c h has a broad tip. W e have d e s i g n e d a

m o d i f i e d Tubbs di la tor wi th a t apered tip w h i c h serves as a one-pass i n s t rumen t for

d i la t ing bo th v e n t r i c u l o t o m y w o u n d and mit ra l valve. It also a l lows ea sy p rob ing o f

severe ly s tenosed mitral va lve or i f ices unde r digi ta l control .

KEY WORDS: dilatation; equipment design; heart surgery; mitral valve; mitral valve stenosis

INTRODUCTION

Transventricular mitral commissurotomy continues to be the treatment of choice for the palliation of mitral valvular stenosis in India 1'2, China 3 and other Asian countries 4. Even in the developed countries, it is still found useful for mitral commissurotomy during pregnancy 5. It comprises digital palpation of the mitral valve through a left atriotomy wound and introduction of a mitral valve dilator (usually Tubbs) through a wound in the left ventricular apex across the stenosed mitral valve. The standard Tubbs dilator has a broad tip and its introduction is facilitated by serial enlargement of the ventriculotomy wound (secured by a purse-string tourniquet) usually with the help of multiple tapered Hager uterine dilators. A tapered one-pass dilator has also been designed 6. We have modified the Tubbs

From the Department of Cardiothoracic Surgery, Jawahar- lal Institute of Postgraduate Medical Education and Research, Pondicherry, India.

Address for correspondence: Dr Amit Banerjee, Type V/4, JIPMER Campus, Pondicherry 605 006, India.

dilator to eliminate the need for prior dilatation of the ventriculotomy.

THE INSTRUMENT

The terminal 1.5 cm of a Tubbs dilator has been tapered so as to give it the appearance of a cone with the blades in a closed position (Fig. I). The

Fig.1 Tapered tip of the modified dilator with blades in closed position

tip is blunt with a width of 2.5 mm to avoid inadvertent injury to intracardiac structures likely to be caused by a pointed tip. The instrument can be directly inserted into the left ventricular chamber through a small ventriculotomy wound which gets adequately dilated during the process of introduction. The dilator blades are deep enough to allow satisfactory,

Modified Tubbs dilator 85

the assistant is inexperienced. It also facilitates introduction of the modified Tubbs dilator through a severely stenosed mitral valve orifice which would not admit a standard Tubbs dilator.

Fig.2 Blades in dilating position showing adequate depth for commissurotomy

measured commissurotomy when open (Fig. 2) even after pushing the tapered portion well into the left atrial chamber. The instrument is now routinely used in our department.

C O M M E N T S

Our modification does away with the step of enlarging the vent r icu lo tomy wound prior to insertion of the dilator. It saves time in case of an emergency, prevents injury to the myocardium caused by repeated manipulation of the purse-string tourniquet and avoids unnecessary blood loss when

References

1. JOHN S, KRISHNASWAMY S, JA1RAJ PS, CHERIAN G, MURALIDHARAN S, SUKUMAR IP. Theprofile and surgical management of mitral stenosis in young patients. J Thorac Cardiovasc Surg 1975; 69: 631-8.

2. JOHN S, BASHI VV, JAIRAJ PS et al. Closed mitral valvotomy: early results and long term follow-up of 3724 consecutivepatients. Circulation 1983; 68: 891-6.

3. LARGE SR. Personal view. Br Med J 1986; 293: 502.

4. MESTRES CA. Letter to the Editor (untitled). Asia Pacific Exchange 1990; 4: 3.

5. COOLEY DA. TechniqueS in Cardiac Surgery. 2nd ed. Philadelphia: WB Saunders, 1984: 201.

6. VICTOR S.A modified ventriculotomy dilator-cum-probe for transventricular mitral commissurotomy. Indian J Thorac Cardiovasc Surg 1985-86; 4: 77-8.