AusI. N.Z. J. S U ~ . 1993, 63, 656-651

INTRA-AORTIC BALLOON RUPTURE: REPLY

JOHN ALVAREZ Department of Cardiothoracic Surgery, Royal North Shore Hospital, Sydney,

New South Wales, Australia

We thank the editor for the opportunity to reply to Dr S. Wolvek’s response to our article, Intra-aortic balloon rupture causing femoral en- trapment,Aust. N.Z. JSurg. 1993,63,72-4.‘

In that article we reported a case of intra- aortic balloon pump (IABP) entrapment second- ary to rupture of the balloon membrane. The IABP was manufactured by Datascope Inc. We also commented on the disturbing increase in the incidence of I M P ruptures with the Datascope balloon. At Royal North Shore Hospital in 1990, 16.5% (5 cases) of all Datascope balloons rup- tured versus a rupture rate with the same balloon of 1.8% (1 case from 56 balloons inserted) over the preceding 2 years.

It is precisely because we experienced a spate of ruptures with this balloon, and our firm belief that we were not an isolated example, that we undertook to investigate what the real situation was across Australia. Our findings were presented at the 7th Inter-General Scientific Meeting of the section of Cardiothoracic Surgery, Sanctuary Cove, 24-26th October, 1991 and subsequently published.* We found, for Australia in 1990, 20 cases of IAEiP rupture, 18 of these were Data- scope balloons, a rupture rate of 5.5%; and in 1991, 21 ruptures, all Datascope balloons, a rup- ture rate of 9%. There were three deaths and six entrapments associated with IABP rupture. Dur- ing the same period five other cardiothoracic centres in Australia reported rupture rates of 2.9-17%, with a mean of 9%, in 1990 and 6.7- 12%, a mean of 10.1%, in 1991. Of particular note is how these figures were calculated. The rupture rate, the number of ruptured IABP re- ported to the authors divided by the number of I D P actually inserted. This fact is crucial be- cause we discovered that in 1990 and 1991, bal- loon insertions accounted for 45% and 65%, respectively, of the total number of balloons sold.

Correspondence: Dr I. Alvarez, Department of Cardiac Surgery, Royal North Shore Hospital, St Leonards, NSW 2065, Australia.

Accepted for publication 28 April 1993.

Dr Wolvek has taken issue with our findings previously3 and we have provided an appropriate reply.4 Again we emphasize that the problem is balloon rupture, when we have had to remove an IABP because of balloon failure, the presence of blood and/or a clot within the balloon membrane and/or the escape of air when the balloon is inflated under water indicates that it has a hole in it. Call it a leak, a penetration, a tear or a rupture but it has a hole in it, the membrane is not intact. Dr Wolvek further takes issue with what we believe the consequences of IABP rup- ture are to an already critically ill patient. He quotes 25 years of published clinical history as supporting his beliefs. This disingenuous state- ment does not stand up to the published facts. We state that the consequences of IABP rupture are: first, ‘Incomplete balloon expansion limits the ability to augment cardiac output’. We have had two patients who lost all cardiac assistance provided by the IABP; one died because of this and the other developed entrapment. However, the latter patient had no balloon assistance and required increased inotropes to stabilize cardiac function. I t is petty semantics to state that mini- mal helium leaks from minute perforations cause trivial loss of balloon augmentation. In Australia, two other patients have died from this acute loss of cardiac assist.’

Second, ‘With altered and incomplete inflation and deflation, thrombus formation is likely to form on its exterior with the risk of subsequent embolization’. At the time of removal of the entrapped balloon not only was clot present with- in the lumen but adherent to its exterior as well. The IABP is a foreign body and despite heparini- zation platelet counts do fall, presumably from adherence to the balloon membrane. Embolic events have been reported with IABP a ~ s i s t . ~

Last, in relation to arterial gas embolization, it is facile for Dr Wolvek to wish us to believe that holes in a balloon membrane are all ‘self’ limit- ing. A review of the same 25 years of published clinical experience has clearly documented deaths and neurological damage secondary to gas cm- bolization from a ruptured balloon

INTRA-AORTIC BALLOON RUPTCIRE REPLY 651

Dr Wolvek correctly points out that the paper by Sutter et al. from the Deborah Heart & Lung Institution (USA), in which they reported a Datascope rupture rate of 48%, was inaccurate.8 As Dr Wolvek is all too aware our paper was accepted for publication by this Journal in Octo- ber 1991, although published in late 1992. Our subsequent article on IABP rupture2 clearly stat- ed the content of Dr Joyce’s reply.9 However, what must be made clear is that the ‘greatly reduced’ rupture rate which Dr Wolvek alludes to in Dr Joyce’s reply was 15.9%, well within the range we have found in Australia. Dr Rutten in 1990 reported from the Netherlands a rupture rate of 13.9% with the Datascope balloon.2

Again, Dr Wolvek states that we make direct allegations about a change in the thickness of the balloon membrane. In the paper published in this journal1 we quoted the findings of Sutter et al.’ Dr Joyce then subsequently corrected this statement in his reply to Dr Wolvek’s comments9 and we too in our most recent paper clearly state that there has been ‘no change in the manufac- turing process’.2

Dr Wolvek states that we blame product de- fects with the Datascope balloon for our series of ruptures. Faced with this sudden occurrence of numerous balloon ruptures all potential contrib- uting factors must be considered. As Dr Wolvek clearly states this was a ‘recent increase’. The facts are that over a period of 10 years, with 303 balloon insertions we had 5 cases of balloon rupture, one was with a Datascope balloon.Io We could identify no change in the patient popula- tion receiving the balloon, the reasons why we insert them or the proceduralists who insert them, and yet in 1990 we had six ruptures.

Of key concern to us was: Why now? Is any one else reporting such problems? Information from Datascope (copy provided to the publisher) stated that the Royal North Shore Hospital ac- counted for 71-80% of all complaints. Clearly our research across Australia, the reports by

Sutter et af. from the USA8 and Rutten from the Netherlands* is evidence enough that we were not an isolated case.

It is painfully clear that not all balloon ruptures are reported. The responsibility lies with the balloon user to notify the balloon producer. But equally clear, once a problem is identified, en- deavours to assess the extent of the problem by the manufacturer have to be improved. It is well to be reminded that ‘if you don’t take a tempera- ture you can’t find a fever’.”

References 1. ALVAREZ J. M., BRADY P. W. & WILSON R. Mc.

(1992) Intra-aortic balloon rupture causing femo- ral entrapment. Ausr. N.Z. J. Surg. 63,72-4.

2. ALVAREZ J. M., BRADY P. W. & WILSON R. Mc. (1992) Intra-aortic balloon rupture: An increasing trend? ASAIO Trans. 38(4), 862-3.

3. WOLVEK S. (1993) Letter to Editor. ASAIO Trans. (in press).

4. ALVAREZ J. M., BRADY P. W. & WILSON R. Mc. (1993) Letter to Editor.ASAl0 Journal (in press).

5. SEIFERT P. E. (1986) Late paraplegia resulting from intra aortic balloon pump. Ann. Thorac. Sue. 41,700.

6. FREDERIKSEN J. W., SMITH J., BROWN P. & ZINEITI C. (1988) Arterial helium embolism from a rup- tured intra-aortic balloon. Ann. Thorac. Surg. 46,

7. SCHEIDT S., WILNER G., MUELLER H. el al. (1973) Intra aortic balloon pumping in cardiogenic shock. N. Engl. J. Med. 288,979-84.

8. S ~ R F. P., JOYCE D. M., BENLEY B. M. ef al. (1991) Events associated with rupture of intra aortic balloon counterpulsation devices. ASAIO Trans. 27,38-40.

9. JOYCE D. M. (1991) Letter to Editor. ASAIO Tmns.

10. ALVAREZ J. M., GATES R., ROWE D. & BRADY P. (1992) Complications from intra aortic balloon counterpulsation: A review of 303 cardiac surgical cases. Eur. J. Cardiothorac. Surg. 6,530-5.

11. SHEM S. (1985) House of GOD. Black Swan Publi- cation, Sydney.

690-2.

37,38-40.