A Novel Fenestration Technique for Abdominal Aortic Dissection Membranes Using a Combination of a Needle Re-entry Catheter and the "Cheese-wire” Technique

Purpose: This study was designed to demonstrate the applicability of a combined needle-based re-entry catheter and "cheese-wire” technique for fenestration of abdominal aortic dissection membranes. Methods: Four male patients (mean age: 65years) with acute complicated aortic type B dissections were treated at our institution by fenestrating the abdominal aortic dissection membrane using a hybrid technique. This technique combined an initial membrane puncture with a needle-based re-entry catheter using a transfemoral approach. A guidewire was passed through the re-entry catheter and across the membrane. Using a contralateral transfemoral access, this guidewire was then snared, creating a through-and-through wire access. The membrane was then fenestrated using the cheese-wire maneuver. Results: We successfully performed: (a) membrane puncture; (b) guidewire passage; (c) guidewire snaring; and (d) cheese-wire maneuver in all four cases. After this maneuver, decompression of the false lumen and acceptable arterial inflow into the true lumen was observed in all cases. The dependent visceral arteries were reperfused. In one case, portions of the fenestrated membrane occluded the common iliac artery, which was immediately and successfully stented. In another case, long-standing intestinal hypoperfusion before the fenestration resulted in reperfusion-related shock and intraoperative death of the patient. Conclusions: The described hybrid approach for fenestration of dissection membranes is technically feasible and may be established as a therapeutic method in cases with a complicated type B dissectio

Endarterectomy of the Aneurysm Sac in Open Abdominal Aortic Aneurysm Repair Reduces Perigraft Seroma and Improves Graft Incorporation

Background: Fluid around the graft in the original aneurysm sac after open abdominal aortic aneurysm (AAA) repair is a poorly researched phenomenon. If large, such perigraft seroma can cause symptoms of compression, and cases of rupture have even been described. We assessed whether endarterectomy of the aneurysm sac reduces the incidence of perigraft fluid and improves graft incorporation. Design and methods: Starting in July 2005, all patients with elective open AAA repair were alternately treated either with conventional thrombectomy or thrombectomy plus endarterectomy of the aneurysm sac. All patients were treated with a polytetrafluoroethylene (PTFE) graft. The maximum axial width of the perigraft fluid collection was measured on computed tomography (CT) scans 1year after operation. Results: The CT scans of 115 patients were available; 56 had endarterectomy of the aneurysm sac and 59 did not. Fluid collections were significantly smaller in patients with endarterectomy (median width 4.0 versus 8.0mm; P=0.0001). Eight patients with endarterectomy had a fluid collection wider than 10mm compared to 28 patients without endarterectomy (OR 0.18, 95% CI 0.07-0.46). After endarterectomy, 17 patients had radiological signs of complete graft incorporation in comparison to only 6 patients without endarterectomy (OR 3.85, 95% CI 1.39-10.66). No patients were symptomatic or reoperated for perigraft seroma. Conclusions: Endarterectomy of the aneurysm sac in open AAA repair appears to improve graft incorporation. The high rate of asymptomatic perigraft seroma is surprising, and its clinical significance is unknown. Ultrafiltration of PTFE grafts may be an underlying mechanis

Complications of retroperitoneoscopic living donor nephrectomy: single center experience after 164 cases

Objectives: Retroperitoneoscopic living donor nephrectomy (RLDN) is used by only a few centers worldwide. Similar to laparoscopic living donor nephrectomy it offers the donor rapid convalescence and excellent cosmetic results. However, concerns have been expressed over the safety of endoscopic living donor nephrectomy. Methods: We review the results of 164 consecutive RLDN from November 2001 to November 2007. Complications were classified into intra- and early postoperative. Results: Mean donor age was 53.4±10.7years (27-79). Left kidneys were harvested in 76% of cases. Mean operation time was 146±44min (55-270), and warm ischemia time 131±45s (50-280). In two patients (1.2%) conversion to open nephrectomy was necessary. The intraoperative complication rate was 3.0%. In the postoperative period we observed in 17.7% minor complications with no persisting impairments for the donor. The rate of major complications in the early postoperative period was 4.3%. Three patients (1.8%) necessitated revision, due to laceration of the external iliac artery in one patient and chyloretroperitoneum in two patients. Mean donor creatinine was 113.1±26.6mg/dl (63-201) on the first postoperative day, and 102.0±22.2mg/dl (68-159) on the fifth postoperative day. Conclusion: Retroperitoneoscopic living donor nephrectomy can be performed with acceptable intraoperative and early postoperative morbidity. Operation times and warm ischemia times are comparable to the open approac

Increased surface expression of CD18 and CD11b in leukocytes after tourniquet ischemia during elective hand surgery

The surface expression of β2-integrins was investigated in leukocytes from patients undergoing ischemia induced by tourniquet application for elective hand surgery. Blood samples were obtained before initiation, at the end of ischemia, and after 15 minutes of reperfusion from ischemic and contralateral arms of five patients. Comparable expression of CD18, CD11a, CD11b, and CD11c could be detected by immunofluorescence in leukocytes from samples drawn from either arm before tourniquet application. In contrast, a significant increase in the expression of CD18 was detectable in monocytes, granulocytes, and lymphocytes from the ischemic arm compared with that in the nonischemic contralateral control, at the end of the ischemia time (80 ± 16 minutes). A significantly increased expression of CD11b, but not CD11a or CD11c, determinants was also observed in granulocytes and monocytes. Concomitantly, a significant reduction in the percentages of granulocytes in samples from ischemic areas was detectable. After 15 minutes of reperfusion, differences in the expression of these adhesion molecules were no longer significant. The expression of the genes encoding interleukins IL-1α, IL-1β, and IL-6 and tumor necrosis factor alpha (TNFα) proinflammatory cytokines was also studied by reverse polymerase chain reaction (rPCR) in peripheral blood mononuclear cells (PBMCs) obtained from the same samples in three patients. IL-1β or IL-6 gene expression was never observed. Expression of IL-1α and TNFα genes, as detected in two patients, was not related with induction of ischemia. However, in these patients expression of one or both these genes was observed in samples derived from the ischemic but not the control arm after 15 minutes of reperfusion. These data document that overexpression of adhesion molecules and sequestration of leukocytes take place following short ischemia times, as routinely applied clinically for minor surgical procedure

Long-term safety and stability of angiogenesis induced by balanced single-vector co-expression of PDGF-BB and VEGF164 in skeletal muscle

Therapeutic angiogenesis by growth factor delivery is an attractive treatment strategy for ischemic diseases, yet clinical efficacy has been elusive. The angiogenic master regulator VEGF-A can induce aberrant angiogenesis if expressed above a threshold level. Since VEGF remains localized in the matrix around expressing cells, homogeneous dose distribution in target tissues is required, which is challenging. We found that co-expression of the pericyte-recruiting factor PDGF-BB at a fixed ratio with VEGF from a single bicistronic vector ensured normal angiogenesis despite heterogeneous high VEGF levels. Taking advantage of a highly controlled gene delivery platform, based on monoclonal populations of transduced myoblasts, in which every cell stably produces the same amount of each factor, here we rigorously investigated a) the dose-dependent effects, and b) the long-term safety and stability of VEGF and PDGF-BB co-expression in skeletal muscle. PDGF-BB co-expression did not affect the normal angiogenesis by low and medium VEGF doses, but specifically prevented vascular tumors by high VEGF, yielding instead normal and mature capillary networks, accompanied by robust arteriole formation. Induced angiogenesis persisted unchanged up to 4 months, while no tumors appeared. Therefore, PDGF-BB co-expression is an attractive strategy to improve safety and efficacy of therapeutic angiogenesis by VEGF gene delivery

Retroperitoneoscopic donor nephrectomy: donor outcome and complication rate in comparison with three different techniques

Four surgical techniques for living donor nephrectomy were analyzed retrospectively in terms of perioperative outcome and early complication rate. A total of 182 donor nephrectomies including 69 open (OLDN), 14 fully laparoscopic (LDN), 34 hand-assisted laparoscopic (HLDN) and 65 retroperitoneoscopic (RLDN) nephrectomies were analyzed. There was a significant difference in mean operating time (OPT) between the OLDN (160min) and RLDN (150min) as compared to the LDN (212min) and HLDN group (192min) (P<0.001). Mean warm ischemia time (WIT) was significantly shorter with OLDN (114s), RLDN (121s) and HLDN (128s) when compared to LDN (238s) (P<0.001). Major complication rate was comparable among the groups. Independent of the preferred technique, donor nephrectomy is associated with complication rates. RLDN is comparable to OLDN in terms of OPT, WIT. Learning endoscopic donor nephrectomy could be associated with a higher complication rat

Extracellular matrix and growth factor engineering for controlled angiogenesis in regenerative medicine

Blood vessel growth plays a key role in regenerative medicine, both to restore blood supply to ischemic tissues and to ensure rapid vascularization of clinical-size tissue-engineered grafts. For example, vascular endothelial growth factor (VEGF) is the master regulator of physiological blood vessel growth and is one of the main molecular targets of therapeutic angiogenesis approaches. However, angiogenesis is a complex process and there is a need to develop rational therapeutic strategies based on a firm understanding of basic vascular biology principles, as evidenced by the disappointing results of initial clinical trials of angiogenic factor delivery. In particular, the spatial localization of angiogenic signals in the extracellular matrix (ECM) is crucial to ensure the proper assembly and maturation of new vascular structures. Here, we discuss the therapeutic implications of matrix interactions of angiogenic factors, with a special emphasis on VEGF, as well as provide an overview of current approaches, based on protein and biomaterial engineering that mimic the regulatory functions of ECM to optimize the signaling microenvironment of vascular growth factors

Cardiovascular imaging following perioperative myocardial infarction/injury

Patients developing perioperative myocardial infarction/injury (PMI) have a high mortality. PMI work-up and therapy remain poorly defined. This prospective multicenter study included high-risk patients undergoing major non-cardiac surgery within a systematic PMI screening and clinical response program. The frequency of cardiovascular imaging during PMI work-up and its yield for possible type 1 myocardial infarction (T1MI) was assessed. Automated PMI detection triggered evaluation by the treating physician/cardiologist, who determined selection/timing of cardiovascular imaging. T1M1 was considered with the presence of a new wall motion abnormality within 30 days in transthoracic echocardiography (TTE), a new scar or ischemia within 90 days in myocardial perfusion imaging (MPI), and Ambrose-Type II or complex lesions within 7 days of PMI in coronary angiography (CA). In patients with PMI, 21% (268/1269) underwent at least one cardiac imaging modality. TTE was used in 13% (163/1269), MPI in 3% (37/1269), and CA in 5% (68/1269). Cardiology consultation was associated with higher use of cardiovascular imaging (27% versus 13%). Signs indicative of T1MI were found in 8% of TTE, 46% of MPI, and 63% of CA. Most patients with PMI did not undergo any cardiovascular imaging within their PMI work-up. If performed, MPI and CA showed high yield for signs indicative of T1MI.Trial registration: https://clinicaltrials.gov/ct2/show/NCT02573532

A novel fenestration technique for abdominal aortic dissection membranes using a combination of a needle re-entry catheter and the "cheese-wire" technique

This study was designed to demonstrate the applicability of a combined needle-based re-entry catheter and "cheese-wire" technique for fenestration of abdominal aortic dissection membranes