Risk factors for the development of antibody-mediated rejection in highly sensitized pediatric kidney transplant recipients.

ABMR remains a significant concern for early graft loss, especially for those who are HS against HLA antigens. We sought to determine the risk factors leading to ABMR in HS pediatric kidney transplant recipients. From January 2009 to December 2015, 16 HS pediatric kidney transplant patients at our center (age range 2-21) were retrospectively reviewed for outcomes and risk factors for ABMR. All HS patients received desensitization with high-dose IVIG/rituximab prior to transplant. Two groups were examined: ABMR+ (n = 7) and ABMR- (n = 9). Patient survival was 100%; however, one patient in the ABMR+ group suffered graft loss from ABMR 16 months post-transplant. ABMR+ patients had higher Class I PRA at the time of transplant (Class I: 73.1 ± 19.1 vs 49.1 ± 28.3, P = .075), although not statistically significant. ABMR+ patients were more likely to have a history of transplant nephrectomy (P = .013). The characteristic that most strongly correlated with ABMR was the DSA-RIS (P = .045), a scoring system used to quantify cumulative intensity of all DSA. In conclusion, DSA, as quantified by the RIS at the time of transplant, should be considered as part of the initial allocation strategy and patients with high RIS monitored closely for ABMR post-transplant.

The Influence of Collagen Impregnation of a Knitted Dacron Patch Used in Carotid Endarterectomy.

BACKGROUND: In selected populations, carotid endarterectomy (CEA) reduces long-term stroke risk. Studies have shown increased risk of restenosis with use of a collagen-impregnated Dacron patch compared to a polytetrafluorethylene patch. There is concern that collagen impregnation may initiate thrombosis or promote restenosis due to platelet activation. We performed a retrospective analysis of our CEA experience with routine patching using knitted Dacron patches with (Hemashield) and without (Sauvage) collagen impregnation. METHODS: Our database was queried for all CEAs between January 2006 and December 2010. Seven surgeons performed 655 CEAs. Patients were excluded if no patch was used (n = 1), a primary CEA was performed before study period or by other surgeons (n = 11), or the patch type was indeterminable (n = 38). Demographics, clinical data, and outcomes were compared between the collagen-impregnated (C, Hemashield) group and non-collagen-impregnated (NC, Sauvage) group. RESULTS: A total of 605 CEAs were analyzed (395 C and 210 NC). Demographics were similar except for coronary artery disease (C 54.3% vs. NC 41.6%, P = 0.003). There was no statistically significant difference in 30-day (C 99.7% vs. NC 99.5%, P > 0.99) or 5-year survival (C 80.0% vs. NC 83.7%, P = 0.26) or 30-day stroke rate (C 0.3% vs. NC 1.0%, P = 0.28). No late ipsilateral strokes occurred during 5-year follow-up. The 5-year freedom from restenosis >30% (C 85.3% vs. NC 86.4%, P = 0.33), restenosis >50% (C 94.5% vs. NC 95.5%, P = 0.44), and restenosis >70% (C 98.6% vs. NC 98.9%, P = 0.73) were similar. Two patients underwent carotid stenting for restenosis >70%. Two patients (both in the C group) developed occlusion of the carotid artery. CONCLUSIONS: The thrombosis and restenosis rates in the 2 groups were similar. This suggests that collagen-impregnated patches do not initiate thrombosis or increase restenosis rates after CEA.

Combined Heart and Kidney Transplantation: Clinical Experience in 100 Consecutive Patients.

Background Combined heart and kidney transplantation ( HKT x) is performed in patients with severe heart failure and advanced renal insufficiency. We analyzed the long-term survival after HKT x, the influence of age and dialysis status, the rates of cardiac rejection, and the influence of sensitization. Methods and Results From June 1992 to December 2016, we performed 100 HKT x procedures. We compared older (≥60 years, n=53) with younger (<60 years, n=47) recipients, and recipients on preoperative dialysis (n=49) and not on dialysis (n=51). We analyzed actuarial freedom from any cardiac rejection, acute cellular rejection, and antibody-mediated rejection, and survival rates by sensitized status with panel-reactive antibody levels <10%, 10% to 50%, and >50%, and compared these survival rates with those from the United Network for Organ Sharing database. There was no difference in 15-year survival between the 2 age groups (35±12.4% and 49±17.3%, ≥60 versus <60 years; P=0.45). There was no difference in 15-year survival between the dialysis and nondialysis groups (44±13.4% and 37±15.2%, P=0.95). Actuarial freedom from any cardiac rejection ( acute cellular rejection >0 or antibody-mediated rejection >0) was 92±2.8% and 84±3.8%, acute cellular rejection (≥2R/3A) 98±1.5% and 94±2.5%, and antibody-mediated rejection (≥1) 96±2.1% and 93±2.6% at 30 days and 1 year after HKT x. There was no difference in the 5-year survival among recipients by sensitization status with panel-reactive antibody levels <10%, 10% to 50%, and >50% (82±5.9%, 83±10.8%, and 92±8.0%; P=0.55). There was no difference in 15-year survival after HKT x between the United Network for Organ Sharing database and our center (38±3.2% and 40±10.1%, respectively; P=0.45). Conclusions HKT x is safe to perform in patients 60 years and older or younger than 60 years and with or without dialysis dependence, with excellent outcomes. The degree of panel-reactive antibody sensitization did not appear to affect survival after HKT x.

Safety and Efficacy of Alemtuzumab Induction in Highly Sensitized Pediatric Renal Transplant Recipients.

BACKGROUND: Studies show that alemtuzumab, a potent lymphocyte-depleting agent, is well tolerated in pediatric renal transplantation. We report on the use of alemtuzumab induction in highly HLA sensitized (HS) pediatric kidney transplant patients. METHODS: Fifty pediatric renal transplants were performed from 1/2009-12/2014. 15 HS patients received IVIG (2 g/kg ×2 doses)/rituximab (375 mg/m ×1) for desensitization with alemtuzumab induction (15-30 mg, 1 dose, subcutaneous), whereas 35 nonsensitized patients received anti-IL-2R. Graft survival and infections were compared between 2 groups. RESULTS: All HS patients had received a prior transplant and were older with lower risk for viral infections due to serostatus. Patient survival was 100%, and graft outcomes were similar with mean 1-year creatinine of 1.03 ± 0.45 versus 0.99 ± 0.6 (P = 0.48). Although a higher incidence of acute cellular rejection was seen in HS patients receiving alemtuzumab (P = 0.001), there was a nonsignificant difference in antibody-mediated rejection. White blood cell and absolute lymphocyte count were significantly lower in alemtuzumab group at 30 days (P < 0.0001) and at 1 year (P = 0.026 and P = 0.001), respectively. There was no significant difference in bacterial, viral, or fungal infections after transplant. CONCLUSIONS: Alemtuzumab induction with desensitization led to nearly equivalent graft survival and functional outcomes in HS pediatric patients as nonsensitized patients receiving anti-IL-2R induction. With this small sample size, we observed significant reduction of white blood cell and absolute lymphocyte count up to 1 year posttransplant. The risk of infection was comparable between the 2 groups; however, patients who received alemtuzumab were older and at lower risk of viral infection due to serostatus.

Carotid reconstruction in nonagenarians: is surgery a viable option?

Because of limited longevity and perceived increased perioperative risk, the optimal treatment of significant carotid stenosis in nonagenarians is controversial. This study was conducted to evaluate our results in this demographic group. A retrospective review was performed of carotid endarterectomies (CEAs) done in nonagenarians at Cedars-Sinai Medical Center between 1996 and 2006. During this period, a total of 2,038 CEAs were performed on patients of all ages. Data abstracted included demographics, patient risk factors, indications for surgery, perioperative complications, and survival. Fifty-three (2.8%) CEAs were performed as the primary procedure on 49 patients aged 90 or greater during the study period. Of these patients, 11 (22.4%) had diabetes, 38 (77.5%) had hypertension, and 31 (63.3%) had coronary artery disease. Eleven patients (22.4%) had a history of smoking, and there were no current smokers. Renal disease was present in three (6.1%) patients, one of whom was dialysis-dependent. The median length of stay was 2 days with a range of 1 to 24 days. Five patients (10.2%) required the intensive care unit following surgery. There were no postoperative strokes, and none of the patients had suffered ipsilateral stroke during follow-up. One patient (1.8%) had a perioperative myocardial infarction. One patient died in the perioperative period (1.8%). The 1-month stroke and mortality results did not differ significantly from those in patients under the age of 90, 0.3% and 0.4%, respectively (p = nonsignificant by Fisher's exact test). Using Kaplan-Meier life-table analysis, the 1- and 5-year survival rates were 84 +/- 5% and 33 +/- 9%, respectively. Our study demonstrates that in a group of well-selected nonagenarians, CEA is a safe procedure with acceptable perioperative morbidity.

Hyperperfusion syndrome after carotid endarterectomy.

The hyperperfusion syndrome is a rare delayed postoperative complication of carotid endarterectomy (CEA) characterized by headache and seizure, with or without intracranial edema or hemorrhage. Between January 1996 and December 2003, 1,602 CEAs were performed. Six patients (0.4%) developed symptoms of hyperperfusion within 2 weeks of surgery. All patients had critical stenoses, five > or =90% and one 80-90%, with poor backbleeding from the distal internal carotid artery noted at operation in all cases. Five patients were asymptomatic prior to operation; one had a hemispheric transient ischemic attack. Three patients had severe contralateral internal carotid disease (two occlusions and one severe stenosis). Two patients developed severe, self-limiting headache that prolonged hospitalization. Three patients had ipsilateral intracranial bleeding, two occurring after an uneventful postoperative course. After initial discharge from the hospital, severe intracranial hemorrhage caused death in two patients. One patient experienced focal seizures 1 week after discharge. Hypertension did not appear to be related to the symptoms in any case. During the study period, the hyperperfusion syndrome caused three of five perioperative strokes (60%) and two of seven deaths (29%) in the entire endarterectomy population. Although rare, the hyperperfusion syndrome accounts for a significant percentage of the neurological morbidity and mortality following CEA.

Early experience with radiofrequency ablation of the greater saphenous vein.

Radiofrequency ablation of the greater saphenous vein (GSV) has been proposed as an alternative to conventional ligation and stripping in the treatment of varicose veins. We have reviewed our initial experience with this new technology in 28 procedures on 24 patients. Preoperative duplex scans confirmed venous valvular incompetence of the GSV in all patients. Intraoperative ultrasound was used to measure the depth of the GSV, to precisely place the radiofrequency catheter adjacent to the saphenofemoral junction, and to confirm the results of the ablative procedure. Occlusion of the GSV was seen on 96% of completion scans and in all patients within 1 week of the procedure. Duplex scans were available for 21 limbs at 3 months and for 3 at 1 year. Persistent occlusion was documented in all cases. No patient had paresthesias or thermal skin injury. Two patients had transient superficial thrombophlebitis around the knee in a treated segment of the GSV. One patient was found to have extension of an asymptomatic, nonocclusive thrombus into the common femoral vein on a routine scan 3 days after surgery. Postoperative patient questionnaires showed that 96% of respondents were very satisfied with the procedure. Radiofrequency ablation of the GSV appears to be a safe alternative to conventional stripping and ligation. Subjective assessment by the surgeons suggests an earlier return to work and active lifestyle compared to traditional extirpative techniques. Longer follow-up is required to establish the durability of the procedure.

Spontaneous infrarenal abdominal aortic dissection presenting as claudication: case report and review of the literature.

Spontaneous infrarenal abdominal aortic dissection (SIAAD) is rare. Patients with SIAAD may be asymptomatic or may present with abdominal pain or lower extremity ischemia. We describe a case report of a patient with SIAAD who presented with claudication. We reviewed the English literature on this disorder and specifically evaluated the differences between patients on the basis of their presenting symptoms. Patients who had SIAAD and lower extremity ischemia were more likely to have the dissection process extend into the iliac or femoral artery and were less likely to have an associated abdominal aortic aneurysm. Aortic rupture in the presence of SIAAD was associated with increased risk of death.

Delayed retroperitoneal arterial hemorrhage after inferior vena cava (IVC) filter insertion: case report and literature review of caval perforations by IVC filters.

Transvenous placement of inferior vena cava (IVC) filters has become commonplace in selected patients with deep venous thrombosis (DVT) and pulmonary embolism (PE). IVC filters have been shown to have excellent therapeutic efficacy and low complication rates. Penetration of the IVC by filter hooks or struts has been reported and commonly noted to be inconsequential. We report a laceration of a lumbar artery by a stainless steel Greenfield (SSG) filter strut that resulted in a near fatal hemorrhage, and review the world literature on caval perforation by IVC filters.

Cryopreserved saphenous vein allografts in infrainguinal revascularization: analysis of 240 grafts.

INTRODUCTION: Cryopreserved saphenous vein allografts (Cryograft; CryoLife, Kennesaw, Ga) have been used as conduit in infrainguinal revascularization when autogenous vein is inadequate or unavailable. Although some studies of Cryografts report poor long-term patency, an anticoagulation protocol may improve outcome. We evaluated our experience with Cryografts to further define their role in lower extremity revascularization. Patients and methods Between March 1992 and March 2002, 240 infrainguinal revascularization procedures with Cryografts were performed in 199 limbs of 177 patients. Eighty-nine percent of procedures were performed because of ischemic rest pain or tissue loss, and 75% of vein grafts were implanted into infrapopliteal targets. Most patients received anticoagulation therapy with warfarin sodium or aspirin, or both, postoperatively. Mean age of the cohort was 78 years; 61% were women; 75% had hypertension, 58% had diabetes, and 38% had renal dysfunction; and 47% were current or past smokers. RESULTS: Mean follow-up was 7 months (range, 0-48 months). Primary patency rate was 83% at 1 month, 50% at 6 months, 30% at 12 months, and 18% at 24 months. Diabetes adversely affected graft patency. Warfarin sodium or antiplatelet therapy did not significantly improve graft patency. Limb salvage was 80% at 1 year and 71% at 2 years. CONCLUSIONS: Cryografts have low primary patency rates that are not affected by anticoagulation with warfarin sodium. Short-term patency of these grafts may be sufficient to heal ischemic wounds and thereby prevent limb loss. However, other less expensive alternatives, eg, prosthetic grafts with vein cuffs, are available and appear to have better patency. Accordingly, use of Cryografts should be limited to revascularization through infected fields in patients without autogenous conduit.

Isolated dissection of the abdominal aorta: clinical presentation and therapeutic options.

INTRODUCTION: Arterial dissection commonly affects the thoracic aorta and is associated with high morbidity and mortality rates. Although dissection of the abdominal aorta is considered rare, liberal use of diagnostic computed tomographic scan imaging for evaluation of abdominal pain has identified this process with increasing frequency. Because the clinical features and therapeutic options of isolated abdominal aortic dissection are not well characterized, we reviewed our recent experience and provide an algorithm for treatment. PATIENTS AND RESULTS: Since 1996, we have treated 10 patients with abdominal aortic dissection. The mean age was 62 +/- 17 years, and 40% were female. Presentation included abdominal pain in seven patients and lower extremity ischemia in one patient. Dissection was asymptomatic in two of the patients. Hypertension, smoking history, remote trauma, and claudication were noted in four, three, two, and two of the patients, respectively. Three patients had abdominal tenderness, three had a pulsatile mass, and five had a benign abdominal examination. The diagnosis of dissection was made on abdominal computed tomographic scan in eight cases, on arteriogram in one case, and at operation in one case. No patient had an associated thoracic aortic dissection. The dissection flap originated below or at the renal arteries in nine of the cases and at the superior mesenteric artery in one case. Length of the dissection ranged between 21 and 110 mm, and in three patients, the dissection flap extended beyond the aortic bifurcation into the common iliac arteries. In three patients who had an aortogram, evidence of flow limitation was found on the basis of the presence of aortic stenosis or occlusion. Treatment consisted of aortic stent graft deployment in one patient, direct aortic reconstruction in three patients, and observation in the remaining six patients. CONCLUSION: Although the natural history of isolated abdominal aortic dissection has not been well defined, our experience adds to the understanding of this rare process. Because aneurysmal degeneration can occur, close surveillance is indicated if definitive treatment is not used initially. Patients with ischemic symptoms and those with intractable pain need intervention, the nature of which should be based on risk profile and aortoiliac anatomy.