The operation-March 17
On Thursday morning, Vinay underwent a complete repair of a double outlet right ventricle and Tetralogy of Fallot. The operating team is set out in the accompanying chart.
In 1992 Dr. Kim Duncan had indicated in a letter to Collins that his long-term plan for Vinay called for a homograft reconstruction of the pulmonary valve in two to three years. A homograft reconstruction involves using cadaver heart tissue to reconstruct the valve. The approach Odim took was a transannular reconstruction. In this procedure, the annulus or ring of the valve is sliced open to widen it and a pericardium patch (a patch taken from the patient's own heart sac) is sutured over the slice to keep the passageway enlarged.
Over time, Vinay's pulmonary valve had become atretic (or non-functional). Odim therefore also performed a pulmonary valvectomy-this involves removal of the atretic pulmonary valve leaflets. Odim explained that he chose not to perform a valve replacement such as Duncan had planned because Vinay's anatomy and physiology would not tolerate the resulting transannular repairs and the regurgitation that might result. As well, Odim said that putting in a valve in a small child meant that the child would have to undergo repeated operations as he grew.
In addition, Odim placed a Dacron patch over the VSD, cut away the muscle in the right ventricle, closed the patent foramen ovale and removed the Blalock-Taussig shunts that Duncan had placed in Vinay.
No witness to this Inquest suggested that there was anything inappropriate in the diagnosis or in Odim's surgical plan.
Fifty-five minutes of partial bypass was required before Vinay was completely weaned from the CPB machine. (Partial bypass is used to support the circulation until the heart functions well enough to allow complete separation from bypass.) It took two attempts and use of inotropic drug support before Vinay could be weaned.
An intra-operative echocardiogram led Giddins to conclude that there was good ventricular performance and an intact VSD patch. However, when transferred to the PICU, Vinay was receiving infusions of three inotropic agents: amrinone, epinephrine and dopamine. The doses of amrinone and epinephrine were moderately large, while the dose of dopamine was relatively low. The use of three inotropes was a sign of the weakened condition of Vinay's heart.
Hudson believed that during the operation there was evidence that the patch had not been successfully applied. One piece of evidence came from the intra-operative measurements of oxygen saturations in various parts of the heart. These measurements showed that the oxygen saturation in the pulmonary artery was ten per cent lower than the level in the right atrium. Such a difference was a sign of a possible leak, leading to shunting. In his report, Hudson wrote:
The most likely site for shunting would be around the VSD patch, because the patent foramen ovale had been closed with sutures. (Exhibit 307, page 3.4)
Hudson also commented on a murmur heard on March 18 in the PICU that also indicated a residual shunt might be present. This murmur had not been heard the day before and was consistent with there being a leak around the patch.
|Current||Home - Table of Contents - Chapter 6 - The operation-March 17|
|Section 1||Chapter 1 - Introduction to the Issues|
|Chapter 2 - Pediatric Cardiac Issues|
|Chapter 3 - The Diagnosis of Pediatric Heart Defects and their Surgical Treatment|
|Chapter 4 - The Health Sciences Centre|
|Section 2||Chapter 5 - Pediatric Cardiac Surgery in Winnipeg 1950-1993|
|Chapter 6 - The Restart of Pediatric Cardiac Surgery in 1994
January 1, 1994 to May 17, 1994
|Chapter 7 - The Slowdown
May 17 to September 1994
|Chapter 8 - Events Leading to the Suspension of the Program
September 7, 1994 to December 23, 1994
|Chapter 9 - 1995 - The Aftermath of the Shutdown
January to March, 1995
|Section 3||Chapter 10 - Findings and Recommendations|
|Appendix 1 - Glossary of terms used in this report|
|Appendix 2 - Parties to the Proceedings and counsel|
|Appendix 3 - List of witnesses and dates of testimony|