Haim Anner

Myocardial infarction after vascular surgery: the role of prolonged stress-induced, ST depression-type ischemia.

OBJECTIVES The goal of this study was to investigate the nature of the association between silent ischemia and postoperative myocardial infarction (PMI). BACKGROUND Silent ischemia predicts cardiac morbidity and mortality in both ambulatory and postoperative patients. Whether silent stress-induced ischemia is merely a marker of extensive coronary artery disease or has a closer association with infarction has not been determined. METHODS In 185 consecutive patients undergoing vascular surgery, we correlated ischemia duration, as detected on a continuous 12-lead ST-trend monitoring during the period 48 h to 72 h after surgery, with cardiac troponin-I (cTn-I) measured in the first three postoperative days and with postoperative cardiac outcome. Postoperative myocardial infarction was defined as cTn-I >3.1 ng/ml accompanied by either typical symptoms or new ischemic electrocardiogram (ECG) findings. RESULTS During 11,132 patient-hours of monitoring, 38 patients (20.5%) had 66 transient ischemic events, all but one denoted by ST-segment depression. Twelve patients (6.5%) sustained PMI; one of those patients died. All infarctions were non-Q-wave and were detected by a rise in cTn-I during or immediately after prolonged, ST depression-type ischemia. The average duration ofischemia in patients with PMI was 226+/-164 min (range: 29 to 625), compared with 38+/-26 min (p = 0.0000) in 26 patients with ischemia but not infarction. Peak cTn-I strongly correlated with the longest, as well as cumulative, ischemia duration (r = 0.83 and r = 0.78, respectively). Ischemic ECG changes were completely reversible in all but one patient who had persistent new T wave inversion. All ischemic events culminating in PMI were preceded by an increase in heart rate (delta heart rate = 32+/-15 beats/min), and most (67%) of them began at the end of surgery and emergence from anesthesia. CONCLUSIONS Prolonged, ST depression-type ischemia progresses to MI and is strongly associated with the majority of cardiac complications after vascular surgery.

Perioperative Myocardial Ischemia in Carotid Endarterectomy Under Cervical Plexus Block and Prophylactic Nitroglycerin Infusion

Perioperative myocardial ischemia was evaluated in 36 consecutive carotid endarterectomy procedures carried out on patients with a high (72.2%) prevalence of ischemic heart disease. The procedures were performed under cervical plexus block plus a prophylactic intravenous nitroglycerin infusion. Findings of myocardial ischemia on perioperative (48 hours) continuous electrocardiogram recordings were correlated with preoperative cardiac status, perioperative continuous intra-arterial blood pressure measurements, and postoperative cardiac outcome. In two patients, ST segment analysis was un-interpretable because of bundle-branch blocks. Altogether, 64 episodes of significant ST segment depression were detected in 18 (52.9%) of the remaining procedures. In 8 (23.5%) procedures, ST segment depressions occurred either during carotid artery clamping at the time of the largest rise in blood pressure or within 2 hours of declamping, when blood pressure tended to decline. There were four (11.7%) postoperative cardiac events: three myocardial infarctions (one Q wave and two non-Q wave) and one episode of unstable angina pectoris. All four patients with cardiac events had early signs of myocardial ischemia either at the time of cross-clamping, or soon after declamping of the carotid artery. All myocardial infarctions developed following prolonged (> 10 hours) myocardial ischemia, starting with the first 20 hours after surgery. Thus, ST segment depression occurring during clamping or soon after carotid declamping was associated with cardiac complications (sensitivity 100% and specificity 86.6%) and suggests the possible usefulness of on-line ST segment trend monitoring.

Results of reconstruction in major pelvic and extremity venous injuries.

PURPOSE Outcome and venous patency after reconstruction in major pelvic and extremity venous injuries was studied. METHODS We retrospectively reviewed 46 patients with 47 venous injuries. RESULTS Injuries were caused by penetrating trauma in 37 extremities, blunt trauma in 6 patients, and were iatrogenic in 4 patients. Pelvic veins were injured in 4 patients, lower-extremity veins were injured in 39 limbs in 38 patients, and upper-extremity veins were injured in 4 patients. Concomitant arterial injuries occurred in 37 patients. Venous repairs were mostly of the complex type and included spiral or panel grafts in 15 (32%) reconstructions, interposition grafts or patch venoplasty in 19 (40%) reconstructions, end-to-end and lateral repair in 11 patients, and ligation in 2 patients. Two patients underwent early amputation. Early transient limb edema occurred in 2 patients, and postoperative venous occlusions were documented in 4 patients. Full function was regained in 39 (81%) extremities. No variable, including 4 retrospectively applied extremity injury scores (mangled extremity severity score [MESS], limb salvage index [LSI], mangled extremity syndrome index [MESI], predictive salvage index [PSI]), correlated with outcome. High values on all 4 scores were significantly associated with reexplorations (P <.02), which were done in 8 patients for debridement (5), arrest of bleeding (2), and repair of a missed arterial injury (1). Follow-up of 28 +/- 6 months on 27 patients (57%; duplex scan in 18, continuous-wave Doppler and plethysmography in 9, and venography in 3) showed 1 occlusion 6 weeks after the injury and patency of all other venous reconstructions. CONCLUSION Reconstructions of major venous injuries with a high rate of complex repairs result in a large proportion of fully functional limbs and a high patency rate. A high extremity injury score predicts the need for reexploration of the extremity. Mostocclusions occur within weeks of injury, and the subsequent delayed occlusion rate is very low.

Urgent endovascular stent-graft placement for traumatic penetrating subclavian artery injuries

Penetrating injuries may infrequently cause pseudoaneurysms, lacerations and arteriovenous fistulas involving the subclavian artery. These injuries present with life-threatening bleedings, associated regional injuries and critical limb ischemia and although surgery has been considered the treatment of choice, subclavian injuries pose a real surgical challenge. We prospectively examined data of six patients presenting with penetrating subclavian artery injuries that were treated by urgent endovascular stent-graft placements. All stent-grafts were deployed successfully achieving complete exclusion of the pseudoaneurysm, control of bleeding and reconstruction of the injured artery. No procedural complications, stent thrombosis or stent infections occurred during hospitalization. One patient developed stenosis at 7 months, which required angioplasty. The series mean clinical and ultrasound-CTA follow-up is 38+/-19.7 months (range 11-60 months) and 28+/-19.1 months (range 6-58 months), respectively. This series shows the feasibility of endovascular repair by means of stent-grafts for selected patients with acute penetrating injuries of the subclavian arteries. This approach proved to be safe and effective in restoring the arterial lumen and patency, excluding the pseudoaneurysms and controlling the bleeding caused by subclavian lacerations. Mid-term follow-up on stent-graft patency rates are encouraging.

The role of combined carotid endarterectomy and coronary artery bypass grafting in the era of carotid stenting in view of long-term results

OBJECTIVES The management of concomitant coronary and carotid artery disease is still in evolution. The surgical options are staged approach--carotid endarterectomy (CEA), followed by coronary artery bypass grafting (CABG) or a reversed-staged approach, or combined approach--CEA and CABG under the same anaesthesia. In view of the percutaneous carotid artery stenting option, we have reviewed our short- and long-term experience with combined CEA and CABG to define the role of this procedure. METHODS From January 1992 to December 2006, we operated on 80 patients performing combined carotid endarterctomy and myocardial revascularization. Short- and long-term results were reviewed. RESULTS Operative mortality was 3.7%. Perioperative cerebrovascular accident (CVA) occurred in 2 patients (2.5%). Perioperative myocardial infarction (MI) occurred in 3 patients (3.7%). Combined complications of death + MI + CVA = 10%. During the mean follow-up of 10 ± 3.2 years (1-14 years), 6 patients (7.6%) had neurological events. Freedom from neurological events for 10 years was 92 ± 4%. Nearly 17 (21.5%) had cardiac events. The 5-year and 10-year survival rates were 74 ± 5 and 62 ± 6%, respectively. CONCLUSIONS Although the short-term results of the non-surgical carotid therapeutic alternative is similar to our surgical results, there are limitations to carotid artery stenting: the need for aggressive antiplatelets therapy, and the haemodynamic changes during the procedure that may be unacceptable for patients with unstable coronary artery disease. Therefore, there is still a role for concomitant surgical CEA and CABG to the results of which the other options should be compared.

A LIFE-THREATENING COMPLICATION OF THE INFUSION PUMP

Serious disturbances in respiration and venous return developed in 2 infants in whom infusion into a central vein was controlled by a peristalic pump. The effects were the result of extravasation which led to build-up of pressure in the medistinum.

Thoracic aorta transobturator bipopliteal bypass as eventual durable reconstruction after removal of an infected aortofemoral graft

A 36-year-old man was referred with aortofemoral graft infection and perigraft duodenal erosion. The aortofemoral graft was removed, and bilateral axillo-superficial femoral grafts were constructed. Recurrent failures of these grafts prompted us to convert to a more-durable reconstruction. A straight graft was anastomosed to the lower thoracic aorta, routed retroperitoneally, and attached to an inverted U-shaped bilateral transobturator bypass graft, which was anastomosed to both above-knee popliteal arteries. After 3 years, the patient has remained well and the grafts are patent. This operation represents a durable in-line reconstruction that avoids all previously infected areas after removal of an infected aortofemoral graft.

Inadvertent subclavian artery cannulation treated by percutaneous closure

Accidental arterial puncture occurs in around 1% and 2.7% of jugular and subclavian approaches, respectively. When a line has been inadvertently inserted into an artery at a noncompressible site, there is an increased risk for serious complications. This complication can be treated by either surgical or endovascular intervention or a combination; however, in critically ill patients or in those with impaired coagulation, therapeutic options are more limited. We describe successful endovascular management of inadvertent subclavian artery cannulation during insertion of a triple lumen central line catheter in a 35-year-old man suffering from leukemia, with sepsis and multi-organ failure. He was hypotensive and hemodynamically unstable, with severe coagulopathy. The catheter had entered the artery at the level of the origin of the internal mammary artery, just above the origin of the vertebral artery. The tip was lying in the aortic arch. The artery was successfully closed by endovascular deployment of an 8 French Angio-Seal device (St. Jude Medical, St. Paul, MN, USA). The device is licensed for use in femoral arterial puncture sites but provided safe and effective closure of the subclavian artery puncture in our patient.

The use of the venous stripper for graft removal in arterial reoperations

A simple technique for removal of synthetic grafts using a standard venous stripper inside the graft is described. The method permits the simultaneous placement of a drainage tube in the canal after graft removal in cases where the graft is infected.