Roles of endovascular aneurysm repair in management of secondary aorto-enteric fistulas.

Secondary aorto-enteric fistulas (AEFs) are an uncommon but serious complication of abdominal aortic aneurysm (AAA) repair. Case review of two cases of secondary AEF are as follows: the first case involved a 75-year- old male who presented with AEF 1 year post-emergency open AAA repair, successfully managed with endovascular aortic aneurysm repair (EVAR) without complication. The second case involved a 75-year-old male patient 14 months post open AAA repair for an inflammatory aneurysm who presented with an iliac-enteric fistula. The previous repair was relined with a bifurcated EVAR with subsequent laparotomy and resection of the affected portion of the small bowel. Both patients on lifelong antibiotics without further episodes of sepsis, recurrence of AEF or mortality at 12 months follow up. EVAR can be successful in the management of secondary AEF. Careful patient selection, accurate image interpretation, and expedient management are key factors to successful short- and long-term outcomes.

Retrograde Stenting Under Transmesenteric Angiographic Guidance of an Occluded Superior Mesenteric Vein to Treat Life-Threatening Hemorrhage.

Midgut carcinoid tumors (MCTs) are responsible for a range of mesenteric vascular complications and may rarely manifest with gastrointestinal (GI) hemorrhage. Endovascular approaches are particularly useful for this population, as surgery is often technically difficult. We report a case of life-threatening upper GI bleeding in a 50-year-old man previously diagnosed with an MCT in the small bowel mesentery. Computed tomography angiogram revealed an MCT obstructing the superior mesenteric vein (SMV) associated with multiple large collateral vessels. The patient underwent retrograde stenting of the obstructed SMV using a combined open and endovascular approach to successfully terminate the persistent GI bleeding.

Hepatic artery embolization in advanced neuroendocrine tumors: Efficacy and long-term outcomes.

INTRODUCTION: Transarterial embolization (TAE) and transarterial chemoembolization (TACE) are established treatments for symptom control in patients with advanced neuroendocrine tumors (NETs) with significant hepatic tumor burden. AIM: To assess efficacy, toxicity and survival parameters in NET patients undergoing TAE and TACE. MATERIALS AND METHODS: A retrospective analysis was carried out of 50 patients with NETs, who underwent a total of 67 embolization procedures in a period of 9 years. All patients had symptomatic and/or radiological progression, despite previous treatments. RESULTS: Symptomatic improvement was observed in 75% of patients who underwent TAE and 57% of patients who had TACE (P = 0.36). Radiological response was observed following 73% of embolization treatments delivered and specifically in 82% of all TAE and 62% of all TACE procedures (P = 0.46). Plasma Chromogranin A (CgA) levels were reduced in 65% of the patients following embolization. Patients with increasing serum CgA levels after treatment had reduced median overall survival (OS) and progression-free survival (PFS) (P = 0.0001). Patients on somatostatin analogs (SSAs) at the time of treatment had improved OS (P = 0.013), but not PFS (P = 0.216). Overall, the differences in OS (P = 0.21) and PFS (P = 0.19) between one mode of treatment over the other were not found to be statistically significant. One- and 5-year OS were 65% and 41% for TACE and 90% and 57% for TAE, respectively. The commonest complication was postembolization syndrome and mortality was 4%. Overall, the complication (P = 0.18) and mortality rates (P = 0.22) were not significantly different between TAE and TACE. CONCLUSIONS: TAE/TACE are beneficial treatments for control of symptoms as well as tumor growth, with acceptable morbidity and mortality rates. No significant efficacy and survival differences were shown between TAE and TACE. Posttreatment CgA levels and the concurrent use of SSAs were independently associated with survival.

Pharmacomechanical thrombolysis in the management of paget-schroetter syndrome.

Paget-Schroetter syndrome (PSS) is a rare form of thoracic outlet syndrome caused by axillosubclavian vein thrombosis which typically presents in healthy young adults. Prompt therapy, traditionally by means of catheter-directed thrombolysis (CDT) prior to definitive surgery, can prevent the subsequent onset of postthrombotic syndrome (PTS) and considerable disability. As CDT is associated with major haemorrhage and high overall treatment cost, pharmacomechanical thrombectomy (PMT) seems to be an attractive alternative which combines pharmacological thrombolysis with mechanical clot disruption. The Trellis-8 peripheral infusion catheter is an example of such a treatment which provides topical thrombolysis in an isolated zone. We describe the use of the Trellis-8 PMT system in the successful management of three patients with PSS.

Temporary axillobifemoral bypass during fenestrated aortic aneurysm repair.

OBJECTIVE: Fenestrated endovascular aortic aneurysm repair (f-EVAR) of juxtarenal aneurysms requiring cannulation of the superior mesenteric artery and renal arteries is technically challenging, has a long operating time, and requires bilateral large-caliber sheath insertion into the femoral arteries. Consequently, the risk of lower limb ischemia and subsequent reperfusion injury is increased. We describe the use of an adjunct temporary axillobifemoral bypass graft (TABFBG) for f-EVAR and propose that it be used as a strategy to avoid ischemia-reperfusion injury in patients anticipated as being at increased risk. METHODS: Consecutive patients from a tertiary referral center undergoing f-EVAR, between October 2008 and August 2011, were retrospectively analyzed. Patients with lower limb arterial occlusive disease and those with difficult anatomy had an adjunct TABFBG. RESULTS: All patients presenting with a juxtarenal aortic aneurysm were treated endovascularly, regardless of aneurysm anatomy and technical difficulties. There were 37 patients without TABFBG (group 1) and 27 with TABFBG (group 2). No patients required open conversion. Sex and age were not significantly different between the groups. The median ankle-brachial pressure index was significantly higher in group 1 (P=.0001). The groups had similar median blood loss, percentage of target vessel cannulation, and median stay in the intensive therapy unit. Morbidities were similar in both groups. There were no significant differences in cardiac, renal, or respiratory complications between the groups. The 30-day mortality was 10.8% (n=4) in group 1 and 0% in group 2 (P=.046). CONCLUSIONS: Our series has demonstrated a significant reduction in mortality (10.8% absolute risk reduction) and no increase in morbidity with the use of a TABFBG for fenestrated grafts. This is likely a result of the reduction in ischemia and ischemia-reperfusion injury in these patients. We therefore recommend the use of TABFBG in patients with proximal severe stenotic or occlusive disease and those in whom an operative time of >4 hours is predicted (typically those for whom three or more target fenestrations is planned).

Appendiceal goblet cell carcinoid tumour: a case of unexpected lung metastasis.

Goblet cell carcinoid tumours are often considered a subset of appendiceal neuroendocrine tumours which behave more aggressively. They usually metastasize through transcoelomic/peritoneal invasion and common sites include the ovaries, peritoneum, and liver. Metastases may have goblet cell carcinoid, signet ring cell carcinoma or classic carcinoid histology. We report the first case in the literature of a patient with a goblet cell carcinoid with lung metastasis, which was associated with unfavourable outcome.

Gastric mixed adenoneuroendocrine carcinoma with a trilineage cell differentiation: case report and review of the literature.

Most gastric neuroendocrine tumours are well differentiated and considered as neuroendocrine neoplasms, whilst poorly differentiated lesions are considered as neuroendocrine carcinomas and account for only 6-16% of gastric neuroendocrine tumours. Gastric mixed adenoneuroendocrine carcinomas are rare malignancies usually composed of a neuroendocrine carcinoma and an adenocarcinoma with a variable grade of differentiation. Here, we report an unusual and rare gastric mixed adenoneuroendocrine carcinoma with a trilineage cell differentiation including a neuroendocrine carcinoma, an adenocarcinoma and a squamous cell carcinoma. A brief discussion of the histopathological features, biological behaviour and treatment of this rare tumour type is presented.

Techniques for removing bilateral renal artery stents prior to fenestrated endovascular aneurysm repair.

PURPOSE: To demonstrate 2 endovascular methods for successful intravascular stent extraction. TECHNIQUE: In preparation for fenestrated endovascular aneurysm repair, renal artery stents may be implanted for focal vessel stenosis at the ostium. In a recent case, bilateral renal artery stents were deployed with >50% protruding into the aortic lumen, thus rendering fenestrated endografting impossible. Two techniques were employed to extract the stents. In the left renal artery, the stent was extracted using an endovascular snare, but the right renal artery stent could not be removed with this method. Instead, an endoscopic forceps was advanced down a 16-F sheath, and the stent was grasped, extracted, and released into the aneurysm sac. The endovascular repair then proceeded in the usual fashion. CONCLUSION: The need to remove a stent prior to endovascular aneurysm repair is not a common problem encountered by most endovascular specialists; however, these methods should be in their armamentarium should the need arise.

Placement of a branched stent graft into the false lumen of a chronic type B aortic dissection.

The treatment of chronic type B aortic dissections remains challenging and controversial. Currently most centers advocate open or endovascular intervention for patients with evidence of malperfusion, rupture or impending rupture, continued pain, or aneurysm formation. Regardless of the type of intervention, the incidence of complications or death remains high, even when undertaken in an elective setting. The standard endovascular treatment usually involves placement of a stent graft into the true lumen of the dissection in an effort to exclude the false lumen. This case report describes the placement of a branched stent graft into the false lumen of a patient with chronic type B dissection to encourage exclusion and thrombosis of the true lumen whilst maintaining flow to all visceral vessels.

Thrombospondin 1 in hypoxia-conditioned media blocks the growth of human microvascular endothelial cells and is increased in systemic sclerosis tissues.

BACKGROUND: Systemic sclerosis (SSc) is a chronic inflammatory autoimmune disease characterised by vascular dysfunction and damage, excess collagen deposition and subsequent organ manifestations. Vasculopathy is an early feature of the disease which leads to a chronic hypoxic environment in the tissues. Paradoxically, there is a lack of angiogenesis. We hypothesised that this may in part be due to a nonphysiological, overriding upregulation in antiangiogenic factors produced by the hypoxic tissues. We considered thrombospondin 1 (TSP-1) as a candidate antiangiogenic factor. RESULTS: Conditioned media from human microvascular endothelial cells cultured in both normoxic and hypoxic environments were able to block endothelial cell proliferation, with the latter environment having a more profound effect. Filtration to remove > 100-kDa proteins or heparin-binding proteins from the conditioned media eliminated their antiproliferative effect. TSP-1 was expressed in high concentrations in the hypoxic media, as was vascular endothelial growth factor (VEGF). Depletion of TSP-1 from the media by immunoprecipitation reduced the antiproliferative effect. We then show that, in a dose-dependent fashion, recombinant TSP-1 blocks the proliferation of endothelial cells. Immunohistochemistry of skin biopsy material revealed that TSP-1 expression was significantly higher throughout the skin of patients with SSc compared with healthy controls. CONCLUSIONS: Despite the environment of chronic tissue hypoxia in SSc, there is a paradoxical absence of angiogenesis. This is thought to be due in part to aberrant expression of antiangiogenic factors, including TSP-1. We have demonstrated that TSP-1 is released in high concentrations by hypoxic endothelial cells. The conditioned media from these cells is able to block proliferation and induce apoptosis in microvascular endothelial cells, an effect that is reduced when TSP-1 is immunoprecipitated out. Further, we have shown that recombinant TSP-1 is able to block proliferation and induce apoptosis at concentrations consistent with those found in the plasma of patients with SSc and that its effect occurs in the presence of elevated VEGF levels. Taken together, these data are consistent with a model wherein injured microvascular cells in SSc fail to repair because of dysregulated induction of TSP-1 in the hypoxic tissues.