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Clinical evidence of Radial Artery spasm immediately after coronary artery bypass graft surgery
Bonaccorsi Héctor; Bauduccio Claudio; Sgrosso José; Dogliotti Ariel.
Instituto Cardiovascular de Rosario. Rosario. Argentina.
Patients and Methods
More than 20 years ago, shortly after its introduction in surgical practice, the bypass with Radial Artery(RA) was abandoned due to the high incidende of early occlusion presumably caused by its spasm. In the begining of this decade its use was revitalized in belief that the availability of new spasmolitic drugs will make the RA in a highly convenient graft to coronary arteries bypass surgery. However there are very few communications that inform the present incidence and the clinical characteristics of the spasms episodies of this arteria in the inmediate postoperative of coronary artery bypass graft surgery(CABG).
To analyze a sample of patients who were subjected to CABG with RA to study the incidence and the clinical characteristics of the spasms episodies of RA in the inmediate postoperative period.
Patients and Methods
The data base of the Cardiac Surgical Intensive Care Unit was analyzed from November 1995 to December 1998. 229 patients were included in the study, who were subjected to CABG with RA.
Cardiopulmonary bypass with a membrane oxygenator was used in all patients under moderate hypothermia(28ºC) and hemodilution. Myocardial protection was achieved by means of cold blood or saline solution.
The RA was removed together with its pedicle including two satellite veins and the surroundig fat tissue. The artery has numerous collateral branches which were occluded using surgical sutures.
Hydrostatic dilation was undertaken at a gentle pressure using a solution of papaverine. The grafts was then stored in the same solution until its use. All patients received orally diltiazem 90-180 mg/day since the first postoperative day unless they would be in unstable hemodynamic condition.
The clinical diagnosis of the RA spasm was based on the following main
Temporary and acute onset ST segment shift in leads of RA distribution zone.
This should have gone with during the episody of 1 or more of the
following minor criteria:
Acute onset ventricular failure.
Acute onset severe ventricular arrhythmia.
Acute onset new bundle branch block.
Acute mitral regurgitation.
Clear response with spasmolitics drugs.
Same zone, recurrent, ST segment shift.
Due to the critical state of the patients we could only do urgent coronary angiography in two of them.
It was diagnosed spasm in the radial conduit by clinical evidence in 4,4% (10/229) of the patients. Since this is a low number of patients we will just make a descriptive analysis of this group.
The preoperative and operative characteristics of the patients who had radial spasm are in table I and II respectively.
Evidence of spasm took place in the operative period in 2(2/10) patients, within the first 24 hs. after surgery in 6(6/10) and on the third day of postoperative period, being in general ward, in 2(2/10) patients.
ST segment shift were elevation in 6(610) patients (mean elevation was 4,7 mm; range 2 a 13 mm) and depression in 4(4/10) (mean depression 2,3 mm; range 2 a 3 mm).
The clinical criteria with which the diagnostic was made is in table III.
The treatment employed during the spasm episodies is in table IV.
The urgent coronary angiography study of 2 patients didn´t show fixed lesions in the bypass, the anastomosis, or the recipient coronary arteries.
The complications observed are shown in table V.
Two patients (2/10) died. One of them because of ventricular arrhthimia and severe cardiac failure during the spasm episody and the other due to multiple orgn failure and sepsis.
The postoperative spasm of the implied conduits in CABG has been described since long time and can involve coronary arteries, Saphenous vein grafts,Left Internal Mammary Artery, Gastroepiploic Artery and RA. [1,2,3,4] This last artery has been proposed by Dr. Carpentier as bypass graft in 1971 but two years later he recomended not to use it due to the high risk of estenosis and oclussion (35%) presumably caused by the postoperative spasm. In the begining of this decade the same medical group revitalized its use, in the belief that new espasmolitics drugs available will turn it in an useful graft in the coronary surgery. However nowadays there´s very little data about features and incidence of RA spasm inmediately after surgery, specially in clinical manifestation.
The prevalence of the spasm of the radial conduit has been informed to be between 3,3 and 10% when analyzing the coronary angiographies taken in the follow up of the patients.[2,1,2] Consequently a rate of clinical episodies near 4% seems to be in accordance to the preceding data. This would put the RA as the conduit that most frequently produce perioperative spasms episodies.
Unfortunately, there is little medical literature that describe in details perioperative RA spasms episodies to compare with the group we analyzed.
It was seem that when the spasm episodies appeared in the intraoperative period or in the first 24 hours after surgery they were serious . The two deaths belong to this group. While the patients who had the spasm further from the surgery, it appeared as electrocardiographic changes of ischemia features without symptoms or other complications.
The highlights diagnosis elements in the spasm radial conduct were the ST segment elevation together with the appearence, in hardly half of the patients, of severe ventricular failure.
In the two cases that urgent coronary angiography could be done, shortly after the begining of the treatment of the spasm, neither fix lesions appeared in the grafts nor in coronary arteries. Angiographic evidence of the spasm was not shown at the moment, presumably because they disappeared with the treatment given.
Remarcably, in spite of administration the treatment currently suggested by literature[1,2], recurrence of the spasm took place in three patients and one patient died because lack of response to the treatment.
This implies to keeping in mind aditional drugs and urgent decisions such as reoperation or percutaneous transluminal coronary angioplasty when the illness threats life.
About one third of the patients with spasm suffer from postoperative myocardial infarction. This is 1,3% of the operated patients, similar amount to 1,9% published by Acar and cols. and 1,8% reported by Weinschelbaum and cols.
This seems to mean that in spite of the infarction rate in people that underwent RA bypass is not high, in the group of patients with spasm of this conduit the postoperative myocardial infarction is a common complication.
Likewise happens with mortality, that reachs 20% of patients with radial spasm, but this only represents 0,9%(2/229) of the patients who received RA conduits in coronary artery bypass graft surgery.
Limits of the report. It´s clear that the accuracy of the diagnosis can only be done with an urgent coronary angiography, however the patient condition turns difficult, risky and not compatible with medical ethics its realization, at least well after the patient condition is stable using the right treatment.
Therefore we based the diagnosis on clinical and electrocardiographic manifestations of the episodies, so we can´t rule out that spasm affects also or exclusively other conduits or coronary arteries.
We cannot also absolutely exclude other causes of early postoperative acute ischemia.
The spasm of the RA bypass is a complication that must be based on clinical criteria for its diagnosis due to the critical state of the patients who undergo it.
Its prevalence seemed to be quite low and similar to the one reported by others authors. Its appearence turns the situation in an emergency, that requires fast diagnosis and treatment. Mortality of patients with this complications is 20%. Nevertheless dead patients due to this cause represents less than 1% of all surgical patients with RA. That is why, in relation with the spasm, the RA, appears nowadays as a very acceptable conduit to make coronary grafts.
Table I: Preoperative data
*Median and range. ptes.: patients
Table II: Operative data
Table III: Diagnosis
Table IV: Treatment
Table V: Complications
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