The operation - March 14
Gary was taken to the operating room at 1215 hours on March 14, 1994. The members of the surgical team are set out in the accompanying chart.
Induction took one hour and forty-four minutes. This was a lengthy time, although there was no evidence to suggest that this contributed to or caused any deterioration in Gary's health. However, the length of induction time in Winnipeg was to become a matter of conflict between Odim and the anaesthetists.
It was difficult to discern from the information on the 1994 perfusion records as to when and how much cardioplegia was given per dose and at what temperature. In his report to this Inquest, Cornel expressed concern about the adequacy of myocardial protection during CPB, since no details of the cardioplegia technique were available.
Cardioplegia is the combination of chemicals and cold solution administered to the heart to stop it from beating and to protect it during a cardiac procedure. The administration of cardioplegia is a matter largely controlled by the surgeon, who decides how and when cardioplegia is administered, but the cardioplegia is actually administered by the perfusionists through the lines connected to the CPB machine.
As events of 1994 unfolded, it became apparent that sometimes, one large dose of cardioplegia might be administered during a case (and might be considered sufficient). At other times, cardioplegia might be administered at the outset of a procedure and then, periodically while the procedure continued, further smaller doses might also be administered.
The record of how and when cardioplegia was administered in this and other cases was maintained by the perfusionists. However, during 1994 the perfusionists simply recorded the total amounts of cardioplegia given and not if it was administered at different times and doses.
Subsequent to these events, a new record-keeping technique has been put in place whereby each dose is recorded separately. It is this latter information that Cornel was unable to determine from the chart and which he felt was of some importance.
The evidence from the perfusionists and from the surgeon was to the effect that they felt that the administration of cardioplegia in this case was adequate to protect the heart. While Cornel's concerns are valid, they point more to a problem with record-keeping than to a problem with cardiac protection in this case. In some of the later cases, however, there is reason to feel that, based on the information available as to how cardioplegia was administered, cardiac protection may not have been adequate. It would not be reasonable to suggest the same in this case, however.
The operation involved repairing the ventricular septal defect with an artificial patch made of Dacron, patching the right ventricular outflow tract with Gary's own pericardium (tissue taken from the sac surrounding the heart), cutting out the muscle bundles from the right ventricle and, according to Odim's notes, tying off the ductus arteriosus. (Given Gary's age and the fact that no PDA was diagnosed, it is likely this was a ligamentum arteriosus.) The muscle bundles in the right ventricle initially obscured Odim's vision of the VSD. For this reason he decided to gain access to the defect through the outlet tract of the right ventricle. He placed sutures around the VSD. A Dacron patch was then secured to each pair of sutures, seating the patch over the hole. Once the patch was put in place, Odim examined the patent foramen ovale and chose not to close it. At that point the team began the process of preparing to go off bypass.
Odim was questioned on the duration of the operation and the bypass time in particular, both of which were considered to be lengthy. He said that:
there were factors that contributed to the bypass time, and potentially factors that could improve on those times. But after sort of reviewing the types of bypass times for this procedure in Winnipeg over the last eight years, I was not impressed with the fact that this time was appreciably more significant than other bypass times in our system. (Evidence, page 24,104)
He acknowledged that the times would have been shorter in Boston or Montreal, but noted that in those locations there would have been three surgeons involved in the operation. He did not believe the operation had been particularly difficult, but he did state that:
It was certainly longer in the initial period, because I was working with people who, and they were working with me, who didn't know techniques or were used to other techniques in the past. And clearly there is a lot of explanation, a lot of this is what I want you to do and that type of thing going on to get the job done. So my feeling was that these types of things would improve with time, as you worked with the personnel. (Evidence, pages 24,105-24,106)
This was one of Odim's early operations in a new setting, a fact that likely contributed to the length of time of the operation. Additionally, Odim's use of interrupted sutures when attaching patches to the heart might also have lengthened the operation. This suturing technique, known as using a pledgetted mattress suture (using many separate sutures), is quite acceptable but can lead to extra time being taken while the patient is on bypass. The alternative, a running suture (or continuous suture), can be put in more quickly, but is less secure.
In her testimony, Youngson said that she believed Odim's suture technique added to the length of the operation:
I remember that it was a struggle, it was difficult, especially in such a little person, a little baby, to have so many sutures in the field. They seemed to be getting tangled from time to time and it was just difficult. (Evidence, page 8,374)
Gary experienced several problems during the course of surgery. The first occurred at 1440 hours, when there was an episode of supraventricular tachycardia (a type of abnormal heart beat or arrhythmia in which the heart beats very quickly). This resulted in a severe drop in blood pressure, just before going on bypass at 1455 hours. The tachycardia was successfully treated by cardioversion (or the application of a mild electrical shock). In his report, Hudson suggested it was common for arrhythmias to occur during manipulation or cannulation of the heart. Gary's oxygen saturation was above sixty per cent during bypass until 1645 hours, when the measurement began falling. The saturation declined to 24 per cent at 1815 hours and then began climbing again.
Throughout the procedure, the team was concerned about Gary's low oxygen saturation. However, once he came off bypass and was treated with a drug used to raise blood pressure, his heart was in a normal rhythm. Odim said he was never able to reach a satisfactory conclusion as to why Gary had experienced such low levels of saturation during the operation.
Gary's chest was initially closed in the operating room. Following this, his blood pressure suddenly decreased at 2045 hours. As a result Odim decided to reopen the chest. When he did so, the chest was found to be oozing blood (a sign of coagulopathy-a clotting problem leading to bleeding). This required treatment with a variety of blood products. In his operative report, Odim wrote, "Hemostasis [stopping of bleeding] was difficult to achieve because of ongoing coagulopathy and we therefore decided to delay sternal closure." (Exhibit 5, page CAR 91)
Delayed sternal closure simply means that Odim decided not to close Gary's chest but to let it remain 'open'-but covered with a silastic membrane (a silicone rubber dressing) in order to prevent infection-while Gary recovered from the operation. This technique is one that is often necessitated by the fact that the heart and the area of the chest where the operation is performed can become swollen as a result of surgery, to the point where closing the chest can impair heart performance. Many things can contribute to swollen heart and chest tissues, including inadequate cardiac protection or the length of the procedure. Odim's operations during 1994 were generally longer than what one would normally expect. ICU staff commented that they perceived that more of his patients with delayed sternal closure had to be reopened in the ICU than they had previously experienced. Gary was transferred to the PICU with a silastic dressing covering his chest.
|Current||Home - Table of Contents - Chapter 6 - The operation - March 14|
|Previous||Conclusion as to Gary's pre-operative status|
|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|