Per Snorre Lingaas

Mechanism of complement activation and its role in the inflammatory response after thoracoabdominal aortic aneurysm repair

Background—Complement activation contributes to ischemia-reperfusion injury. Patients undergoing thoracoabdominal aortic aneurysm (TAAA) repair suffer extensive ischemia-reperfusion and considerable systemic inflammation. Methods and Results—The degree and mechanism of complement activation and its role in inflammation were investigated in 19 patients undergoing TAAA repair. Patients undergoing open infrarenal aortic surgery (n=5) or endovascular descending aortic aneurysm repair (n=6) served as control subjects. Substantial complement activation was seen in TAAA patients but not in controls. C1rs-C1-inhibitor complexes increased moderately, whereas C4bc, C3bBbP, C3bc, and the terminal SC5b-9 complex (TCC) increased markedly after reperfusion, reaching a maximum 8 hours after reperfusion. Interleukin (IL)-1&bgr;, tumor necrosis factor &agr; (TNF-&agr;), and IL-8 increased significantly in TAAA patients but not in controls, peaking at 24 hours postoperatively and correlating closely with the degree of complement activation. IL-6 and IL-10 increased to a maximum 8 hours after reperfusion in the TAAA patients, were not correlated with complement activation, and increased moderately in the control subjects. Myeloperoxidase and lactoferrin increased markedly before reperfusion in all groups, whereas sICAM-1, sP-selectin, and sE-selectin were unchanged. No increase was observed in complement activation products, IL-1&bgr;, TNF-&agr;, or IL-8 in a mannose-binding lectin (MBL)–deficient TAAA patient, whereas IL-6, IL-10, myeloperoxidase, and lactoferrin increased as in the controls. Two other MBL-deficient TAAA patients receiving plasma attained significant MBL levels and showed complement and cytokine patterns identical to the MBL-sufficient TAAA patients. Conclusions—The data suggest that complement activation during TAAA repair is MBL mediated, amplified through the alternative pathway, and responsible in part for the inflammatory response.

Multiple bacteria in aortic aneurysms

OBJECTIVE The purpose of the present study was to reexamine the possibility that bacteria, particularly anaerobes, are present in aortic aneurysms. METHODS From December 2000 to November 2001, 53 samples from aneurysm walls were collected from 49 patients during reconstructive surgery. The tissue specimens were sectioned and cultured under anaerobic conditions. Twenty-eight specimens were also subjected to scanning or transmission electron microscopy. RESULTS Anaerobic cultivation yielded bacteria in 14 of the 53 samples (26.4%). All bacteria were gram-positive cocci or rods from nine genera and 12 species. Five cultures (35%) were mixed, containing two bacterial species. Mixed aerobic and anaerobic species were found in four samples (28.5%). Anaerobic bacteria were recovered from 10 of 14 positive cultures (71%). Among anaerobes found were Propionibacterium acnes, Propionibacterium granulosum, Actinomyces viscosus, Actinomyces naeslundii, and Eggerthella lenta. Coaggregating bacteria of different sizes and structure were found on the aneurysm walls and inside the intravascular plaque at electron microscopy. Bacteria were found in 20 of the 28 samples (71%) examined with scanning or transmission electron microscopy. CONCLUSION Multiple bacteria, many of which did not belong to the indigenous skin microflora, colonize aortic aneurysms. It is not clear whether the bacteria contribute to weakening of the aortic wall by eliciting inflammation or whether they are secondary colonizers of aneurysms.

Intracoronary Shunt Prevents Ischemia in Off-Pump Coronary Artery Bypass Surgery

BACKGROUND The purpose of this study was to evaluate the role of intracoronary shunt during off-pump coronary artery bypass surgery. METHODS Fifty-six patients undergoing off-pump coronary artery bypass using the left internal mammary artery to bypass the left anterior descending coronary artery were randomly assigned to have the bypass performed with intracoronary shunt or by occlusive snaring. Ischemia during grafting was monitored by tissue Doppler. Hemodynamic status and indicators of ischemia were monitored, and on-table and postoperative angiography were performed. RESULTS In patients with retrograde filling of the left anterior descending coronary artery, ischemia did not develop, but occlusion of antegradely perfused vessels caused ischemia in 26 of 33 patients. Ischemia was reversed in 14 of 16 shunted patients, and in 3 of 17 nonshunted cases (p = 0.004). Angiography showed a trend toward improved on-table angiographic results in shunted patients. After 3 months, graft patency was 100%, but 1 patient treated without shunt required reintervention and 15 patients had new angiographic lesions, equally distributed between shunted and nonshunted patients. CONCLUSIONS Intracoronary shunt prevents ischemia during grafting of the left anterior descending coronary artery and provides satisfactory immediate- and short-term graft patency.

[Carotis stenosis-open surgery and endovascular treatment].

BACKGROUND Patients who have a carotid stenosis and suffer a TIA have a high risk of stroke shortly afterwards, and should be offered prophylactic surgery within 2 weeks. We present the results for treatment of carotid stenosis from Oslo University Hospital, Rikshospitalet in the period 2001-2008. MATERIAL AND METHODS The material comprises all patients treated for carotid stenosis, with either carotid thrombendarterectomy (CEA) or endovascular stenting, in the period 2001-2008. All procedures were prospectively recorded in a database. A neurologist examines the patients before, and 1 and 12 months after treatment. RESULTS 408 carotid stenoses were treated in the observation period. Median age (range) was 68 years (21-85), and 125 (31 %) patients were women. 206 (64.2 %) of the 321 stenoses treated with CEA were symptomatic as were 53 (61 %) of the 87 who underwent endovascular treatment (87). The rate of serious stroke and/or death within 30 days after CEA was 1.9 % for symptomatic stenoses and 1.1 % for asymptomatic stenoses; after endovascular treatment the corresponding numbers were 1.9 % and 3.8 %. INTERPRETATION We have offered endovascular treatment to patients in whom surgery would be complicated (restenosis, radiation-induced stenosis etc). Results could therefore not be compared within our material. CEA prevents stroke, and it has been shown that the risk of complications is higher with stenting. Evaluation and treatment of patients with carotid stenosis should be included in the planned National guidelines for stroke treatment.

Carotid Doppler microembolic signals in patients one year after heart valve surgery

Doppler ultrasound has been used to detect microemboli during and after cardiopulmonary bypass (CPB). The aim of the present study was to examine the frequency of microembolic signals (MES) in patients one year after heart valve replacement, to look for possible risk factors associated with MES and for any correlation with cerebral events. One hundred patients, 69 male and 31 female, mean age 66.3±12.4 years, were examined one year after heart valve replacement. Thirty patients, 61% male and 39% female, mean age 62.5±8.7 years, who had undergone cardiovascular operations without heart valve pathology served as controls. A newly developed micro-emboli detector, EMEX-25 (Hatteland Instrumentering, Norway) was used to detect MES from both carotid arteries. MES were detected in 61% of the valve patients. A correlation was found between the number of MES, previous cardiovascular operations, emergency surgery and EuroSCORE (p<0.05). There was no correlation between the number of MES and the level of anticoagulation expressed as international normalization ratio (INR), atrial fibrillation, serum-cholesterol, New York heart association (NYHA) class, gender, age, valve type or valve position. The average number of MES was not increased in seven patients who had experienced major (three) or minor (transient, four) cerebral events during follow-up. In the 30 nonvalve controls, MES were detected in 46% of the patients. MES were detected in valve patients as well as in nonvalve patients one year after surgery. In valve patients, a significant correlation was found between MES and previous surgery, emergency surgery and EuroSCORE. There was no correlation between the number of MES and INR level or postoperative cerebral events.

Cardiovascular surgery in Loeys–Dietz syndrome types 1–4

OBJECTIVES The first publication of Loeys-Dietz syndrome (LDS) described aortic rupture at young ages. Experience with new LDS types showed that the clinical course varies, and thresholds for prophylactic surgery are discussed. As this is an uncommon disease, experience needs to be shared. METHODS Retrospective review of patients with LDS types 1-4 undergoing cardiovascular surgery during the years 1991-2016. RESULTS Thirty-five patients (including 6 children with LDS2) underwent 57 operations. LDS 1, 2, 3 and 4 included 4, 17, 11 and 3 patients, respectively. Mean age at first surgery was 36 years, with a non-significant trend that LDS2 patients were younger. Of the 9 emergency surgeries, 7 were type A dissections, with 1 postoperative death. Twenty-two patients had prophylactic aortic root surgery (17 valve-sparing root replacements), with 1 postoperative death, 1 reoperation with valve replacement and 1 late death. Freedom from root reintervention and death was 92% at 13 years. Of the 11 patients with LDS3, 5 needed mitral valve surgery. Mitral valve disease was not found in the other LDS types. Ten patients needed >1 operation. Of the 57 operations, 33 were in the ascending aorta, 20 in the aorta distal to the arch including branches and 4 were isolated heart surgeries. Of the 20 vascular operations, 16 were in LDS2. Cumulative survival 20 years after first surgery (all patients) was 94.3%. CONCLUSIONS Clinical course seems to be more aggressive in LDS2, with index operation at a younger age, and higher risk of needing several operations. Vascular disease distal to the arch is not uncommon. LDS3 seems to be associated with mitral valve disease. Prophylactic aortic root surgery is safe and durable.

Long-term follow-up of patients operated with the symmetry proximal connector device.

Objective The Symmetry proximal connector device was introduced as a facilitator for construction of proximal anastomosis in coronary bypass surgery. Use of the connector made it unnecessary to clamp the ascending aorta. Early results were promising, but a controlled study performed in our center demonstrated poor angiographic patency of saphenous veins attached with the connector. The objective of this study was to investigate long-term clinical results in patients operated with connector or traditional suture technique. Methods At a minimum of 5 years after surgery, medical records of 46 patients who had undergone off-pump coronary bypass with Symmetry (n = 23) or traditional suture (n = 23) were examined, and the patients were interviewed personally by phone. Patients were asked about the presence of angina pectoris, hospital admission for cardiac conditions, or the need for new interventions. The Norwegian population registry was used to document survival status. Results Two control patients and five Symmetry patients died during the observation period (P = 0.414). Seven Symmetry and one control patient required reintervention (P = 0.015). Of the patients who were interviewed, 8 of 19 Symmetry patients suffered from angina and none of 20 control patients (P = 0.003). Conclusions Patients who were operated with the Symmetry connector device have a high chance of having cardiac ischemia in the intermediate to long term after surgery, despite of relatively frequent reintervention. Patients operated with this connector requires close clinical follow-up.