Vascular

The aim of this report was to compare polyester vs. bovine pericardial patching during CEA with regards to the incidence of early neurologic events and recurrent stenosis.

One hundred and twenty-five consecutive patients with high grade symptomatic (14%) or asymptomatic (86%) carotid artery stenosis (>70%) who underwent 139 CEAs by a single surgeon between January 1997 and April 2001 were retrospectively reviewed. Patients were assessed postoperatively clinically and with routine follow-up duplex scanning. Recurrent stenosis was defined as a narrowing in the common or internal carotid artery of more than 50% by duplex ultrasound examination.

From January 1997 to May 1999, a polyester patch was routinely used in 81 (58%) patients, while between June 1999 and April 2001, a bovine pericardium patch was exclusively used in 59 (42%) patients. There were no ipsilateral postoperative TIAs or strokes in either group. The combined 30-day mortality rate for both groups was 0.8%. One patient in the polyester patch group died from cardiopulmonary complications 10 days after discharge. The length of follow-up in the bovine pericardial patch group was 3–28 months (mean 12 months), while in the polyester patch group was 1–50 months (mean 24.5 month). One patient developed a carotid pseudoaneurysm of the suture line in the bovine pericardium patch group caused by a local infection after previous neck dissection and radiation. The incidence of recurrent stenosis was two patients (4%) in the bovine pericardium group as opposed to six patients (7.6%) in the polyester patch group.

Although this is a preliminary report, it is concluded that bovine pericardium provides excellent perioperative results and is at least comparable to polyester patching in terms of safety. Our study with short term follow up suggests that bovine pericardium patching during carotid endarterectomy may have a lower restenosis rate compared to knitted polyester patching. Clear superiority of bovine pericardium as a patch material awaits a prospective randomised study with long-term follow-up.

α₁-adrenoceptor activation confers myocardial protection from ischemic injury. We tested whether norepinephrine mediates delayed cardioprotection against stunning and whether this alters postischemic arrhythmias.

New Zealand White rabbits were assigned to three groups: Control-group (n = 7): no drugs. Norepinephrine-group (n = 7): 75 μg norepinephrine/kg bodyweight (bw). Norepinephrine/prazosin-group (n = 7):75 μg norepinephrine and 15 μg prazosin/kg bw. After 24 h, hearts were excised, perfused with buffer and subjected to 20 min of ischemia followed by 120 min of reperfusion.

(a) Developed pressures (dP) (P _syst–P _diast) at the end of reperfusion: C: 51.2 ± 5.0%, NE: 71.7 ± 5.1% (p < 0.05 vs. C), NEP: 50.7 ± 5.0%. (b) Ventricular extra beats (vebs) were detected throughout the experiments. C: 0.41 ± 0.15 vebs/min, NE: 1.06 ± 0.18 vebs/min (p < 0.05 vs. C), NEP: 1.17 ± 0.3 vebs/min.

Norepinephrine confers delayed preconditioning against myocardial stunning via an α₁-adrenoceptor mediated pathway. Norepinephrine-mediated preconditioning involves a beneficial effect towards stunning, but at the expense of a higher rate of postischemic ventricular arrhythmia.

To evaluate the feasibility of robotically enhanced preparation of internal mammary arteries (IMA).

Via three trocars in left thoracic wall the left, right or both IMA were skeletonized under CO₂ insufflation and single lung ventilation using electrocautery.

In 12 months, 26 LIMA, five BIMA and one RIMA were dissected. In five patients, the procedure had to be determined (IMA injury (two), respiratory insufficiency (two), and heart penetration (one)). Mean intrathoracic pressure was 9.7 ± 1.5 mmHg. Mean time for LIMA and RIMA dissection was 66.7 ± 21.1 and 99.2 ± 8.7 min, respectively. In 10 patients, pericardium was incised and course of LAD assessed. However, in two patients, this coronary did not correlate with LAD. Time for instrument change depended on type of tool (cautery blade: 24.9 ± 13.1 s, clip applier 72.8 ± 28.4 s).

Robotic dissection of IMA is reasonable. However, life-threatening complications can barely be managed due to inadequate tools and excessive time for instrument change. Incorrect determination of coronaries can result in misplaced anastomoses.

Three myocardial protection techniques were evaluated in a prospective, randomised trial during coronary artery bypass grafts in 69 patients.

Twenty seven patients received intermittent hyperkalaemic undiluted warm blood anterograde cardioplegia (AC), 21 received continuous hyperkalaemic undiluted warm blood retrograde cardioplegia (RC) and 21 received intermittent, hyperkalaemic, diluted cold blood (15 °C), anterograde cardioplegia (CC). Assessment criteria were clinical, laboratory and haemodynamic.

Groups were homogeneous in terms of age, sex, cardiovascular risk factors, severity of coronary disease, preoperative ejection fraction, and number of bypass grafts performed. The oxygen extraction coefficient, and lactate and troponin production in the coronary sinus on aortic unclamping was not significantly different between the three groups. The base excess was −0.19 ± 0.13 in the RC group, −0.18 ± 0.52 in the AC group and −2.67 ± 0.59 in the CC group (P < 0.01 CC vs. AC and CC vs. RC). The priming volume was 1485 ± 64 ml (CC), 1317 ± 44 ml (RC) and 1318 ± 30 ml (AC) (P < 0.05 CC vs. AC and CC vs. RC). The haematocrit during CPB was 28.9 ± 0.9 (CC), 32.5 ± 0.8 (RC) and 32 ± 0.7 (AC) (P < 0.05 CC vs. AC and CC vs. RC). The volume of crystalloid delivered was 735 ± 85 ml (CC), 362 ± 67 ml (RC) and 357 ± 105 ml (AC) (P < 0.05 CC vs. AC and CC vs. RC). The incidence of ventricular fibrillation on aortic unclamping was 61.9% (CC), 9.5% (RC) and 0% (AC) (P < 0.01 CC vs. AC and CC vs. RC). The transfusion rate, duration of intubation, postoperative troponin level, complication rate and mortality were not significantly different between the three groups. Haemodynamic parameters at H2, H4, H8 did not vary significantly between the three groups.

These three techniques appear to be comparable in terms of myocardial protection. Anterograde cardioplegia ensures an identical degree of security to retrograde cardioplegia regardless of the coronary lesions, apart from redo lesions. CC requires greater haemodilution of the patients during CPB.

The development of a saphenous vein graft aneurysm (SVGA) after coronary artery bypass graft surgery is a rare occurrence. There are approximately 60 cases reported in the literature, the majority being single case reports. There is no consensus on the treatment of SVGA.

Retrospective analysis of the patients treated with SVGA was performed at our institution. Demographic and co-morbidity data were acquired on the patients. Patients who underwent surgical treatment were compared to those treated conservatively with the primary outcome being survival time from diagnosis of the SVGA.

Thirteen patients with 15 SVGA were identified. The average age at the time of the most recent coronary artery bypass grafting (CABG) was similar in the conservative and the surgically treated groups (55 vs. 56.5 years, respectively). The average number of grafts per patient at the most recent CABG was similar (3.83 vs. 4.0, respectively). The average time from CABG to diagnosis was similar in both the groups (12.6 vs. 15 years, respectively). The average survival from diagnosis was similar in both the groups (2.3 vs. 1.5 years, respectively, p > 0.05).

Early surgical treatment of SVGA does not provide longer short-term survival compared with conservative management. A treatment algorithm for SVGA based upon patient co-morbidities and aneurysm characteristics is proposed.