Rajiv K. Vohra

Surgical Versus Endovascular Reconstruction for Chronic Mesenteric Ischemia: A Contemporary UK Series

Objective: To assess the outcome of surgical (SR) and endovascular (ER) reconstruction for chronic mesenteric ischemia (CMI). Methods: Retrospective review of consecutive patients who underwent SR or ER for CMI in 3 UK vascular surgery units between 1996 and 2006. Early (<30 days; technical success, morbidity, mortality, length of hospital stay) and late (>30 days) outcomes (symptom recurrence, vessel/graft patency, reintervention, mortality) were assessed. Results: A total of 27 patients underwent 32 reconstructions (SR = 17, ER = 15). A total of 44 of 56 (79%) diseased arteries underwent SR (n = 26; bypass = 24, reimplantation = 2; occlusion = 16, stenosis = 10) or ER (n = 18; stenosis = 16, occlusion = 2). Perioperative mortality for SR and ER was 6% and 0%, respectively (P ≥ .99). Hospital stay was shorter following ER (mean, 4.3 vs. 14.2 days, P = .0003). Mean (range) follow-up for SR and ER was 34 (1-94) and 34 (0-135) months, respectively. At 2 years, SR demonstrated superior secondary patency (100% vs. 65%) and clinical patency (100% vs. 73%). Conclusions: Surgical mesenteric reconstruction is associated with significantly longer hospital stay, but superior long-term outcome compared to endovascular reconstruction.

Coagulation, fibrinolysis, and platelet activation in patients undergoing open and endovascular repair of abdominal aortic aneurysm

BACKGROUND Endovascular aneurysm repair (EVAR) is associated with an improved perioperative mortality compared to open surgical repair. This benefit may reflect reduced incidence of microvascular and macrovascular thrombotic complications after EVAR. PURPOSE The purpose of this study was to review and compare the effects of abdominal aortic aneurysm (AAA), open surgical repair, and EVAR on coagulation, fibrinolysis, and platelet activation. METHODS A MEDLINE (1966-2010) and Cochrane library search for articles relating to the effects of AAA, open surgical repair, and EVAR on hemostasis was performed utilizing and cross-linking terms such as clotting, fibrinolysis, AAA, EVAR, and open surgical repair. Studies with a small cohort of patients (less than 7) or in which values of assessed biomarkers were not included were rejected. RESULTS AAA is associated with increased thrombin generation, activity, and fibrin turnover as evidenced by increased plasma levels of thrombin-antithrombin III-complex (TAT), activated protein C-protein C inhibitor (APC-PCI), fibrin-monomer-fibrinogen (FM-F), F1+2, fibrinogen, and D-dimer. The extent of hemostatic derangement correlates with the volume of intraluminal thrombus. This procoagulant state is exaggerated in the immediate perioperative period after both open surgical repair and EVAR, but is attenuated at medium-term follow-up although not normalized. CONCLUSION The resultant prothrombotic diathesis after open surgical repair and EVAR may account for the high level of perioperative thrombotic complications.

Failure of Endovascular Stenting for Popliteal Cystic Disease

We describe an attempted endovascular stenting for popliteal artery stenosis secondary to adventitial cystic disease in a 56-year-old man with lifestyle-limiting claudication. Despite technical success, it remained patent only for 1 week, requiring interposition venous graft reconstruction eventually.

Changes in thrombin generation, fibrinolysis, platelet and endothelial cell activity, and inflammation following endovascular abdominal aortic aneurysm repair.

BACKGROUND Abdominal aortic aneurysm (AAA) is a chronic inflammatory condition associated with a prothrombotic, hypofibrinolytic diathesis that may increase the risk of cardiovascular events. The effect of endovascular aneurysm repair (EVAR) on this prothrombotic diathesis is not fully understood, especially over the medium and long term. A better understanding of these postintervention changes may improve the risk of cardiovascular complications in the long term. The purpose of this study was to examine thrombin generation, fibrinolysis, platelet and endothelial activation, and the inflammatory response during the 12 months following EVAR. METHODS Twenty-nine patients (mean age, 76.9 years) undergoing EVAR for AAA (mean diameter 6.9 cm) had prothrombin fragment (PF) 1 + 2, thrombin-antithrombin complex (TAT), plasminogen activator inhibitor (PAI) activity, tissue plasminogen activator (t-PA) activity and antigen, soluble P- and E-selectin, and highly sensitive C-reactive protein (hsCRP) measured before and at 24 hours, and 1, 6, and 12 months after surgery. RESULTS PF1 + 2 were markedly elevated prior to EVAR and remained so at 24 hours and 1 month, but had decreased significantly at 6 and 12 months. TAT was also elevated prior to EVAR and increased still further by 24 hours, but fell to below baseline levels thereafter. PAI activity and t-PA antigen were normal prior to EVAR, increased significantly at 24 hours, and then fell to baseline levels. t-PA activity was only detectable at 1 and 6 months; there was a significant rise in soluble P- and E-selectin after EVAR, which was sustained for 12 months. hsCRP increased transiently in response to EVAR but returned to preoperative levels by 1 month. CONCLUSIONS The prothrombotic, hypofibrinolytic diathesis associated with AAA is normalized 12 months after EVAR. This beneficial systemic effect of EVAR for AAA disease may help protect patients against future thromboembolic cardiovascular events.

Carotid Artery Pseudoaneurysm After Carotid Endarterectomy: Case Series and a Review of the Literature

Background: Pseudoaneurysm (PA) after carotid endarterectomy (CEA) is a rare complication with incidence less than 1%. There is a potential for rupture, embolization, thrombosis or compression of cranial nerves. Objective: We reviewed our experience and compare it to the literature to raise awareness of this rare though serious condition. It is crucial to treat these patients early to avoid the hazardous consequences. Methods: A review of the case records of patients who had CEA at University Hospital Birmingham (UHB) NHS Foundation Trust from 1990-2007, was undertaken. Information of patients including their aetiology, presenting features, treatment and results was collected. The English-language literature was searched using PubMed database for post CEA pseudoaneurysm. Results: Five patients developed post CEA PA. This represents 0.4% of the 1200 CEA performed at our hospital in the last 18 years. The timing of their presentation varied from three days to eight months after the original operation. All had patch reconstruction after CEA. Patches were intact at exploration of the PAs. There was one death and one stroke. The literature revealed 154 carotid PAs after CEA and two cases following carotid stenting 52 of these cases had infected PA. Patients with synthetic patches have the least incidence of infection. More than 80% had open surgery and 9% had endovascular repair. Conclusion: Post CEA surveillance is necessary to detect patients with PA early. Factors that favour infection must be avoided. Endovascular repair of carotid PA should be encouraged in specialised centres.

The relationship between aortic aneurysm sac thrombus volume on coagulation, fibrinolysis and platelet activity.

AIM Abdominal aortic aneurysm (AAA) is associated with chronic mural inflammation and a pro-thrombotic diathesis. It has been suggested that both may be related to biologically active intra-sac thrombus. The aim of this study was to examine the relationship between thrombin generation, fibrinolysis, platelet activity and AAA sac thrombus volume. METHODS 30 patients (29 men) of median (IQR) age 75 (71-82) years with an infra-renal AAA >5.5 cm in antero-posterior diameter were prospectively studied. AAA, lumen and thrombus volumes were calculated using a CT workstation (Vitrea). Plasma thrombin-antithrombin (TAT), plasminogen activator inhibitor (PAI)-1, and soluble (s) P-selectin were measured as biomarkers of coagulation, fibrinolysis and platelet activity, respectively RESULTS Median (IQR) AAA total, lumen and thrombus volumes were 188 (147-247) cm(3), 80 (54.3-107) cm(3) and 97.6 (63-127) cm(3) respectively. TAT levels were significantly higher (median, QR, 7.15 [4.7-31.3] μg/L, p=<0.001) and sP-selectin levels significantly lower (median, IQR, 80.5 [68-128] ng/ml, p=<0.0001) than the normal range. PAI-1 levels (median, IQR, 20.9 [8.4-50.7] ng/ml) were normal. There was no correlation between AAA thrombus volume and PAI-1 (r=-0.25, p=0.47), sP-Selectin (r=0.26, p=0.43) or TAT plasma levels (r=-0.21, p=0.54). CONCLUSION The present study confirms that patients with AAA demonstrate haemostatic derangement, but the extent of the haemostatic derangement does not correlate with AAA sac thrombus volume.

Effect of endovascular and open abdominal aortic aneurysm repair on thrombin generation and fibrinolysis

BACKGROUND Abdominal aortic aneurysm (AAA) is associated with a prothrombotic diathesis that may increase the risk of cardiovascular events. This diathesis is exacerbated in the short term by open aneurysm repair (OAR) and endovascular aneurysm repair (EVAR). However, the effect of EVAR and OAR on coagulation and fibrinolysis in the medium and long term is poorly understood. The purpose of this study was to investigate the medium-term effects of EVAR and OAR on thrombin generation, neutralization, and fibrinolysis. METHODS Prothrombin fragment (PF)1+2, thrombin antithrombin (TAT) complex, plasminogen activator inhibitor (PAI) activity, and tissue-plasminogen activator (t-PA) antigen were measured in eight age-matched controls (AMCs), 29 patients with AAA immediately before (preoperatively) and 12 months after EVAR (post-EVAR), and in 11 patients at a mean of 16 months after OAR (post-OAR). RESULTS Preoperatively, PF1+2 levels were significantly higher in patients with AAAs than in AMC. PF1+2 levels post-EVAR and post-OAR were significantly lower than preoperative values and similar to AMC. There was no significant difference in TAT, PAI, or t-PA between AMC, AAA preoperatively, and post-EVAR. Post-OAR, PAI activity was significantly higher than in preoperative patients. CONCLUSIONS AAA is associated with increased thrombin generation without upregulation of fibrinolysis. The prothrombotic, hypofibrinolytic diathesis observed in patients with AAA returns toward normal in the medium term after EVAR and OAR, although there is a trend toward decreased fibrinolysis post-OAR.

Ethnic differences in the prevalence of peripheral arterial disease: a systematic review and meta-analysis

ABSTRACT Background: Previous studies have demonstrated higher rates of peripheral arterial disease (PAD) in blacks and lower in Asians compared to whites. The aim of this study is to undertake a comprehensive review of literature on ethnic differences in the epidemiology of PAD. Methods: A systemic review and meta-analysis included studies reporting PAD prevalence in general or diabetic populations, and comparing PAD prevalence in ethnic groups. Results: Mean prevalence of PAD in general population for whites, blacks and Asians was 3.5%, 6.7% and 3.7% respectively. Meta-analysis demonstrated higher prevalence of PAD in blacks (p < 0.001) and lower amongst Asians (p < 0.001), compared to whites. In diabetic population, the mean prevalence of PAD for whites, blacks, east Asians and south Asians was 17%, 25.3%, 13.5% and 7.6% respectively. In diabetic population, south Asians had a lower PAD prevalence (p < 0.001) compared to whites; there was no significant difference between blacks and whites. Overall females have higher PAD rates, in general (3.8% vs 3.2%; p < 0.001) and in diabetic population (13.7% vs 10%; p < 0.001). Conclusion: Blacks are vulnerable to PAD, in contrast to Asians who have lower prevalence of PAD when compared to whites. Further research is needed in order to identify the factors that generate this difference.

Brachial Plexus Lipomata Presenting with Neurogenic and Venous Thoracic Outlet Syndrome: Case Reports and Review of the Literature

BACKGROUND Compression of the brachial plexus causing neurogenic symptoms is involved in most cases referred to vascular surgeons for consideration of treatment of thoracic outlet syndrome (TOS). The causative factor of the compression can be difficult to diagnose with multiple pathologies implicated. METHODS We present 2 rare cases of supraclavicular lipomata causing compression of the neurovascular structures in the thoracic outlet. The only 6 other cases of brachial plexus lipomata were described to our knowledge in the literature worldwide. RESULTS We highlight that there are a small number of neurogenic TOS cases where the causative pathology can be successfully managed by surgery with expectation of a good recovery. CONCLUSIONS Surgeons operating on these lesions can expect good symptom resolution for their patients.

Assessment of Renal Function by Means of Cystatin C Following Standard and Fenestrated Endovascular Aneurysm Repair

BACKGROUND Cystatin C (Cyst C) is more sensitive marker for early renal injury. However, serum creatinine (sCr) and estimated glomerular filtration rate (eGFR) are still used as the standard renal markers after endovascular aortic aneurysm repair (EVAR). The goal of this study was to compare the efficacy of Cyst C, sCr, and eGFR as markers of renal function after EVAR. PATIENTS AND METHODS This study examined 29 patients (27 men) with a mean age of 76.9 years (range, 55-89 years) undergoing standard (n = 19) and fenestrated (n = 10) EVAR for abdominal aortic aneurysm (AAA) of mean diameter 6.9 cm (range, 5.5-10 cm). Cyst C and sCr were measured and eGFR calculated before and 1 day and 1, 6, and 12 months after EVAR. RESULTS At 24 hours after procedure, a significant increase in Cyst C (P < 0.005) and sCr (P = 0.028) and significant decrease in eGFR (P = 0.04) were seen. Cyst C continued to increase and was significantly higher at 1 (P < 0.002), 6 (P < 0.005), and 12 (P < 0.005) months compared with baseline. By contrast, sCr and eGFR did not show any significant change at 1, 6, and 12 months from the baseline level. Cyst C increased significantly postoperatively regardless of the baseline renal function. None of the patients required renal replacement therapy. CONCLUSIONS EVAR is associated with a significant increase in Cyst C starting 24 hours after the procedure and is maintained for 12 months. sCr and eGFR only show significant change at 24 hours and therefore may underestimate long-term renal damage after EVAR.