Jeffery B. Dattilo

Analysis of functional renal allograft tolerance with single-dose rapamycin based induction immunosuppression.

The induction of transplantation tolerance is one of the primary goals following solid organ transplantation. The combination of a single dose of rapamycin (RAPA) with a short course of cyclosporine (CsA) has been shown to induce transplantation tolerance in the nonfunctional rat heterotopic cardiac transplant model. The purpose of this study was to assess this effective induction protocol in a functional renal transplant model. Male ACI (RTl(a)) and Lewis (RT1(1)) rats were used as donor and recipients respectively. Allografts received a single RAPA dose of (1.5 mg/kg) combined with CsA (10 mg/kg) 12-14 hr prior to transplantation. CsA (5 mg/kg) was given daily on days +1 - +7. Untreated Lewis to Lewis isografts served as histological controls. Chimerism, assessed in recipient skin, and intragraft interleukin (IL) 10 expression was determined utilizing PCR and RT-PCR techniques respectively. Treated animals and isografts were sacrificed 120-130 days posttransplant for functional and histological evaluation. Allografts (n=9) were functionally tolerant with serum creatinine (0.77+/-0.1 vs. 0.88+/-0.1; P=0.275), blood urea nitrogen (37.6+/-4.6 vs. 23.3+/-1.9; P=0.123), and 24 hr protein excretion (27.0+/-4.4 vs. 17.9+/-5.2; P=0.131) similar to single kidney ACI controls. Histologically, 45% (4/9) allografts were indistinguishable from isografts with no evidence of rejection, and were considered immunologically tolerant. Donor/recipient chimerism was not detected. All immunologically tolerant allografts had evidence of intragraft IL-10 expression. Rejecting allografts and isografts did not express intragraft IL-10. This study confirms the efficacy of pre-engraftment single-dose RAPA combined with CsA in inducing true immunologic tolerance in this stringent functional renal transplant model. The expression of intragraft IL-10 in tolerant recipients suggests a Th-2 shift as the mechanism of tolerance in this model.

Mega-aneurysmal degeneration of a saphenous vein graft following infrainguinal bypass: A case report

True aneurysm formation in infrainguinal autologous vein grafts is rare. The authors report a case of a patient presenting with extensive aneurysmal degeneration of a femoropopliteal bypass vein graft 13 years after the original operation and 8 years after graft revision and thrombolysis for acute occlusion. Over a 2-year period, the vein graft aneurysm expanded from 2.7 to 4.5 cm maximal diameter. He underwent exclusion and partial resection of the vein graft aneurysm with placement of a new femoropopliteal bypass using reversed saphenous vein from the contralateral leg. Histopathologic examination of the aneurysm revealed intimal fibrosis, medial degeneration, and inflammation. This case and review of the literature suggests that true infrainguinal vein graft aneurysms occur infrequently and massive aneurysm degeneration is even more uncommon. Because of the rarity of true infrainguinal vein graft aneurysms, their etiology remains unclear.

Retroperitoneal repair of abdominal aortic aneurysms offers postoperative benefits to male patients in the Veterans Affairs Health System.

BACKGROUND Transperitoneal (TP) and retroperitoneal (RP) approaches have equal efficacy in elective open abdominal aortic aneurysm (AAA) repair. The effect of open operative approach on patient-specific outcomes after AAA repair was tested. METHODS Consecutive patients undergoing open AAA repair at the Veterans Affairs Tennessee Valley Healthcare System between January 2000 and August 2008 were retrospectively reviewed. Analysis was performed to examine the effects of demographic and clinical covariates on postoperative outcomes. RESULTS A total of 106 patients were identified: 54 with TP approach and 52 with RP approach. Demographics and preoperative comorbidities were equivalent (p > or = 0.10), with the exception of chronic obstructive pulmonary disease which was more prevalent in the TP group (61 vs. 40%). Operative times were longer in the TP group (4.6 vs. 3.5 hours; p < 0.01); however, significantly more TP patients had reconstruction with a bifurcated graft (72 vs. 2%; p < 0.01). Postoperative nasogastric tube decompression times were shorter in the RP group (1 vs. 3 days; p < 0.01), and RP approach led to a quicker return to preoperative diet (4 vs. 6 days; p = 0.05). Patients undergoing RP repair developed fewer incisional hernias (2 vs. 15%; p = 0.03). CONCLUSION RP approach to AAA repair offers patients faster return of bowel function and is associated with fewer incisional hernias.

Minimally Invasive Vein Harvesting: A Comparison of Endoscopic Versus Traditional Open Saphenectomy:

The greater saphenous vein (SV) is the conduit of choice for coronary and infrapopliteal revascularization procedures. Unfortunately, to harvest an SV it is often necessary to make an incision the length of the leg, and this is associated with a significant incidence of wound complications. Minimally invasive procedures have several advantages including reduced incidence of wound complications, decreased hospital length of stay, and, therefore, health-care savings. Currently, little information is available that compares traditional open saphenectomy (OS) versus a minimally invasive procedure, endoscopic saphenectomy (ES). The purpose of this study was to compare SV harvest time, incision length, and harvested vein quality between the OS and ES techniques in six nonpreserved cadavers. Each limb was randomly selected for either OS or ES. The length of incision, number of SV leaks after harvest, length of SV, and time required for harvest were recorded for each technique. (continued on next page) The table summarizes the findings of the cadaver dissections. Per limb, no difference was noted in vein harvest length or number of leaks between OS and ES. A significant reduction was found in incision length for ES (14.4 ±1.4 cm per limb), but the time required for OS was significantly shorter (P=0.01). This study suggests an equivalent length of SV can be harvested with either OS or ES techniques; however, with the ES technique there is a reduction in incision length and, therefore, a less morbid operative technique.