Angiographic and electron-beam computed tomography studies of retrograde cardioplegia via the coronary sinus

Retrograde cardioplegia revisited: open technique for long aortic cross clamping

BACKGROUND

The efficacy of retrograde cardioplegia for myocardial protection is still controversial. In our institution, we exclusively use intermittent administration of tepid, undiluted blood supplemented with potassium and magnesium for the cases with aortic insufficiency, requiring aortotomy, or undergoing mitral valve repair. In using this retrograde technique, we make a point of cannulating a retrograde perfusion catheter under direct vision following right atriotomy. The purpose of this retrospective study is to evaluate the clinical outcome of using this technique.

METHODS

This study comprises 49 patients who underwent elective valve surgery using direct-vision retrograde cardioplegia exclusively, requiring more than 3h aortic cross-clamping. Their clinical outcome was reviewed retrospectively.

RESULTS

There was no hospital mortality in this study. No patient was noted to have evidence of mediastinitis, myocardial infarction, or cerebral complications in the postoperative period. The case requiring the longest aortic cross-clamping time (380 min) survived the operation without the use of intra-aortic balloon pumping or percutaneous cardiopulmonary support, and the postoperative course was uneventful.

CONCLUSIONS

Our result suggests that direct-vision retrograde cardioplegia is a safe and effective method of cardioplegia delivery, and provides a longer period of myocardial protection than previously thought.

Laser fluorescence angiography reveals perfusion defects in retrograde cardioplegia

BACKGROUND

Adequate perfusion of the right ventricle with retrograde cardioplegia has always been questioned. However, clinical studies suggested sufficient protection and, up to now, intraoperative assessment of cardioplegia distribution has been difficult.

METHODS

As a pilot study in 14 patients, we used indocyanine green laser fluorescence angiography (ICGLA) to assess vascular and myocardial perfusion of different areas of the right anterior ventricular wall. Regions of interest were analyzed quantitatively using a new software package.

RESULTS

ICGLA allowed rapid and reliable visualization of cardioplegic flow and distribution. Retrograde cardioplegia revealed perfusion defects in the territory of the right anterior cardiac veins when compared to antegrade delivery and to areas close to the left anterior descending vein(s), confirmed by quantitative analyses of maximal fluorescence intensity. Five patients were excluded from quantitative analyses. The learning curve, pitfalls, limitations and special image details are described.

CONCLUSION

A larger study is necessary to examine the relevance of perfusion defects to metabolic changes in affected myocytes and to global right ventricular function.

Electrical impedancemetry a new method for evaluating myocardial protection in operations with heart extracorporeal circulation

Objective: to determine the information content of electrical impedancemetry as a method of assessing myocardial protection during cardioplegic different versions. The study included 54 patients operated on in the emergency department of valvular defects surgery at Bakulev's Medical Center. Depending on the method of myocardial protection patients were divided into 3 groups: Group 1 - patients whom Buckberg cardioplegia was used (n = 31), group 2 - patients underwent cardioplegia solution with Custodiol (n = 9), group 3 - patients who have a perioperative myocardial protection used hyperkalium solution (n = 14). All patients were studied bioelectrical impedance of the myocardium. The results showed that the electrical impedancemetry can well assess the state of the myocardium during surgery.

The anatomic variability of the coronary vasculature of the human heart — Part II: some anatomical peculiarities of arteriovenous relations

The arteriovenous relations in human heart are, in some instances, different from arteriovenous relations in other parts of the body. The specific relations between cardiac arteries and veins may enable diffusible substances carried through the system of juxta-arterial cardiac veins to influence the regulation of the lumen of the coronary arteries. Arteriovenous anastomoses (6% of our 150 cases) permit direct communication between the arteries and veins bypassing the capillary circulation; it is assumed that these anastomoses prevent coagulation of blood in small veins. In cases of arterial occlusion, the myocardium is supplied by veins that allow retrograde vascularization of the myocardium. In 33% of our cases the posterior atrial branches (0.5-1.0 mm in diameter) of the coronary arteries ran through the wall of the coronary venous sinus on their way from the parent vessel, which lay in the coronary sulcus, to the left atrium. In 11% of the cases, the arterial branch that ran through the distal portion of the wall of the coronary sinus was the interatrial branch. The blood flow through the parietal arteries of the venous coronary sinus probably depends on the condition of the muscular layer of the sinus during the phases of cardiac action, and this might be important in the course of certain cardiosurgical procedures.

Anatomic and hemodynamic considerations influencing the efficiency of retrograde cardioplegia

One of the major issues raised by cardiac surgical procedures requiring cardiopulmonary bypass is the question of myocardial protection. The preferred route for the administration of cardioplegia is controversial. A number of studies show the beneficial effects of retrograde cardioplegia but some demonstrate only partial or poor myocardial protection. This paper reviews the anatomy and anatomic variations of the coronary sinus, the coronary sinus orifice and cardiac veins, and the major systemic venous drainage, all of which may affect the distribution of retrograde cardioplegia.

Retrograde crystalloid cardioplegia preserves left ventricular systolic function better than antegrade cardioplegia in patients with occluded coronary arteries

OBJECTIVE

To investigate retrograde and antegrade crystalloid cardioplegia in terms of cardiac cooling and postoperative cardiac function.

DESIGN

Prospective, randomized, and blinded.

SETTING

University hospital.

PARTICIPANTS

Twenty male patients with triple-vessel disease and proximal occlusion of the circumflex or the left anterior descending coronary artery.

INTERVENTIONS

Left ventricular ejection fraction at rest and during exercise was evaluated by nuclear ventriculography the day before and 3 months after surgery. After induction of anesthesia and hourly for the first 5 postoperative hours, hemodynamic, echocardiographic, and electrocardiographic data were acquired. Myocardial temperature was measured with needle thermistors in 3 myocardial regions.

MEASUREMENTS AND MAIN RESULTS

Demographic and temperature data were analyzed by t-test. Hemodynamic and echocardiographic data were analyzed by analysis of variance. The groups were similar in baseline characteristics. Retrograde cardioplegia cooled the region distal to an occlusion better than antegrade cardioplegia (9.6 degrees C +/- 4.8 degrees C v 21.8 degrees C +/- 5.9 degrees C; p < 0.01). Hemodynamic, echocardiographic, and electrocardiographic data did not differ between the groups. Three months after surgery, the retrograde cardioplegia group showed a higher left ventricular ejection fraction at rest (58% +/- 10% v 47% +/- 10%; p < 0.02) and during exercise (58% +/- 13% v 47% +/- 10%; p < 0.05) compared with the antegrade cardioplegia group.

CONCLUSIONS

Retrograde cardioplegia provides more homogenous myocardial cooling than antegrade cardioplegia in hearts with coronary artery occlusions. The use of retrograde cardioplegia seems to benefit long-term left ventricular function.

Assessment of right ventricular function postretrograde cardioplegia by transesophageal echocardiography

The impact of continuous retrograde cardioplegia (RCP) on right ventricular (RV) function was evaluated prospectively with intraoperative transesophageal echocardiography (TEE) in 36 patients (23 males, 13 females) with a mean age of 60.4 years (ages 24-82). Operative procedures included 12 aortic valve replacements, 16 mitral valve repair/replacements, both with or without an associated cardiac operation, and 8 Ross procedures. Mean cardiopulmonary bypass (CPB) time was 123.3 minutes (66-280 minutes) with an average cross-clamp time of 88.9 minutes (43-199 minutes). The amount of cold blood RCP ranged from 3160-18,500 mL (mean = 7382.5), and the average pulmonary artery pressure was 35/18 mmHg. The coronary sinus was distally snared in 11 patients. TEE documented biventricular global dysfunction in two patients and post-CPB with preservation of the left ventricular function in all other patients. Localized akinesis of the RV apex and outflow tract were noted in three patients, and isolated worsening tricuspid insufficiency of moderate to severe intensity in six patients. Two of the six patients with worsening tricuspid insufficiency belonged to the snared coronary sinus group (11 patients). All of the documented RV dysfunctions were new and showed no correlation with the perfusion data.

IN CONCLUSION

(1) RV apex, RV outflow tract and tricuspid valve were particularly subject to important dysfunction post-RCP; (2) RCP did not protect RV adequately in 11 patients (31%); and (3) TEE is a convenient intraoperative technique in evaluating RV dysfunction.