Thoracotomy for correction of a kinked right internal mammary artery graft

Near-fatal kinking of mammary graft due to emphysematous lung disease

Left internal mammary artery grafting is commonly used in elective coronary artery bypass graft surgery. We report a near-fatal case with graft kinking upon sternal closure due to distended, emphysematous lungs impinging on the mammary graft. After the sternum was closed, the patient suffered a severe hemodynamic deterioration. Surgical examination revealed kinking of his left internal mammary artery upon sternal closure due to distended, emphysematous lungs impinging on the mammary graft. Using an off-bypass technique, the kink in the mammary graft to the left anterior descending artery was removed by moving the origin of the left internal mammary artery to a hooded graft of a saphenous vein graft instead. In this position, the graft no longer was impinged upon by the distended emphysematous lungs. Subsequently, the patient’s sternum was closed without hemodynamic impingement. Although chronic obstructive pulmonary disease is well described to increase complications in coronary artery bypass graft surgery, it has not been previously associated with the kinking of a left internal mammary artery. This report highlights another contribution that chronic obstructive pulmonary disease can make to increased morbidity following coronary artery bypass graft surgery and alerts readers to watch for this complication in susceptible patients.

Transient right internal thoracic arterial graft kink related to respiratory movements: documentation of its existence, relevance and proposed management

In this case report, we provide the first detailed description of an intermittent mechanical kink of a right internal thoracic artery (ITA) graft to the left anterior descending coronary artery secondary to respiratory movements, and its assessment by pressure wire derived fractional flow reserve (FFR). The patient presented with recurrent unstable angina and documented anterior/anterolateral ischemia. Persistent symptoms were attributed to the ITA kink and stenting was planned on clinical grounds. However, the lesion proved not physiologically significant when FFR was assessed after intermittency related to respiratory movements was documented. Complex stenting was therefore avoided and medical therapy was prescribed for distal diagonal disease. We therefore propose that intermittency should be actively investigated when a kink is documented in a coronary bypass graft by conventional angiography (using dedicated angiographic evaluation in maximal inspiration and expiration). Furthermore, when this type of lesion is encountered, we suggest that it should be assessed physiologically using pressure wire derived FFR before potentially complex interventions are considered.

Kinking of internal thoracic artery graft without symptoms: should it be revised?

BACKGROUND

Surgery or intervention therapy has been performed to correct kinks of internal thoracic artery (ITA) grafts. The aim of this study was to evaluate the natural course of the ITA graft kink and to clarify whether surgery or intervention therapy should be performed in asymptomatic patients during the early postoperative period.

METHODS

We investigated the early and follow-up angiographic results of ITA graft kinks in 7 consecutive patients who did not undergo surgical or interventional correction. The graft diameter and percentage of diameter stenosis at the kink site were compared between the early postoperative angiography and the follow-up angiography.

RESULTS

Early postoperative angiography revealed that the diameter stenosis at the kink site was 60.1% +/- 6.9% (range, 51 to 69) and the diameter at the kink site was 0.92 +/- 0.20 mm (range, 0.63% to 1.25%). The ITA kinks disappeared in all the patients and the diameter of the ITA graft adjacent to the kink was not significantly changed on the follow-up angiography. No luminal irregularity or indentation was shown. All the patients had been free from cardiac events until the follow-up angiography.

CONCLUSION

Kinking of an ITA graft that's seen on the early postoperative angiography might improve without surgery or intervention. The natural course of ITA graft kinks should be considered when detecting these kinks on the early postoperative angiography when the patient is asymptomatic.

Pitfalls of Skeletonized Internal Thoracic Artery:

BACKGROUND AND AIM OF THE STUDY

Skeletonization of the internal thoracic artery (ITA) has several advantages: sequential bypass grafting can be easily performed, and a graft of increased length can make the distal coronary artery accessible. However, kinking of the grafts has been observed on postoperative angiograms in a few cases. We investigated whether there were significant differences in the frequency of graft kinking and stenosis degree at the kink site between pedicled and skeletonized grafts.

METHODS

Postoperative angiography was performed for all cases. In pedicled (n = 65) and skeletonized (n = 129) groups, the results of postoperative graft angiography were analyzed to investigate the presence of graft kinking and stenosis degree at the kink site.

RESULTS

Kinking was observed in 4 (5.9%) and 9 (3.9%) arteries in the pedicled and skeletonized groups, respectively (p = 0.341). The stenosis degree at the kink site (mean +/- SD) was significantly higher in the skeletonized group (47.2 +/- 16.8%) than in the pedicled group (23.5 +/- 13.7%), (p = 0.032). In four patients in whom early postoperative angiography showed a kink with more than 50% stenosis, late-term angiography was performed. All four cases showed regression of the stenosis degree at the kink site.

CONCLUSIONS

When the ITA had a kink, the stenosis degree at the kink site was significantly higher in the skeletonized group than in the pedicled group. Late angiography often reveals regression of stenosis at the kink site. Immediate intervention need not always be performed if the patient has no angina caused by a stenotic lesion at the kink site.

Steal phenomenon with kinked graft caused a loss of viability in a dialysis patient

A 74-year-old man with chronic renal failure under hemodialysis via the left upper extremity underwent an off-pump coronary artery bypass (OPCAB). The left internal thoracic artery (LITA), which was harvested in a skeletonized manner, was anastomosed to the left anterior descending artery (LAD). Postoperatively, he complained of chest pain only during dialysis. Angiography revealed a kinking in the LITA. However, myocardial scintigraphy revealed no ischemia. One year after OPCAB, left ventriculography revealed akinesis and myocardial scintigraphy revealed no viability in the anterior wall. This suggested that the viability was lost due to graft kinking and steal phenomenon during hemodialysis. If the length of the skeletonized ITA graft is redundant, kinking of the graft rarely occurs after the chest is closed. We also suggest that to avoid the kinking of the ITA graft, fibrin glue should be used to paste the ITA graft running in a gentle curve.