Endovascular Management of Central Venous Stenoses in the Hemodialysis Patient: Results of Percutaneous Therapy

The purpose of this study was to determine the functional results of transvenous angioplasty for the treatment of central venous stenoses in patients with failing upper extremity arteriovenous access. Two hundred consecutive patients presented with threatened arteriovenous access from January 1999 through July 2002. Angiographic evidence of central venous stenosis was present in 35 patients (18%) (superior vena cava 5, brachiocephalic veins 14, and subclavian veins 18). Follow-up averaged 873 days from the date of initial intervention. The initial technical success rate was 89%. Primary patency for each intervention was 85% at 30 days, 55% at 6 months, 43% at 1 year, and 0% at 2 years. Assisted primary patency rates were 88% at 30 days, 80% at 1 year, and 64% at 2 years. Freedom from central venous dialysis catheter placement was 82% at 30 days, 63% at 3 months, 51% at 1 year, 37% at 2 years, and 25% at 3 years. Freedom from a dialysis catheter was superior in those patients with autogenous arteriovenous fistulas. Transvenous angioplasty appears to be beneficial for hemodialysis patients with central venous stenoses, and it helps preserve functional access in the affected extremity, particularly in patients with autogenous fistulas.

The Relationship of Human Saphenous Vein Smooth Muscle Contractile Responses to Donor Age and Gender

The smooth muscle contractile properties of 100 human saphenous veins derived from healthy tissue and organ donors were investigated. No significant changes in the contractile responses of saphenous veins to potassium chloride, serotonin, and norepinephrine were associated with age. In contrast, comparison of contractile responses between males and females demonstrated significantly less response to potassium chloride in female veins (P<0.05). Female contractile responses to serotonin (P=0.74) and norepinephrine (P= 0.29) did not differ significantly when compared with male responses. These observations support the conclusion that gender may be an important variable in saphenous vein biology.

The Relationship of Human Saphenous Vein Intimal Area to Age and Gender

The saphenous vein is an essential element in arterial bypass surgery. It is known to develop intimal thickening following transplantation to the arterial circulation. No data are available on the relationship of normal saphenous vein intimal area and the age or the gender of the patient. One hundred sixty-two consecutive, donated, cadaveric, midtibial samples of the long saphenous vein were harvested. The donors ranged in age from twelve to eighty-two years; there were 121 males and 41 females. The areas of the intima and media and the intimal ratio (intimal area/[intimal + medial area]) were calculated by computer videomorphometry. There was no correlation between the three variables and age, but there was a significant correlation between the gender of the donor and the intimal area (r2=0.25, P=0.0012) and the intimal ratio (r2=0.34, p = 0.0001) showing that females have a greater intimal area than males.

These findings suggest that gender should be considered as a variable in the choice of suitable control values in subsequent human studies on the development of intimal hyperplasia in venous bypass grafts.

Catheter Thrombolysis of Thrombosed Hepatic Arteries in Liver Transplant Recipients: Predictors of Success and Role of Thrombolysis

Hepatic artery thrombosis is an uncommon complication of liver transplantation. However, it is a major indication for re-transplantation. The use of transcatheter thrombolysis and subsequent surgical revascularization as a graft salvage procedure is discussed. Four of 5 cases (80%) were successful in re-establishing flow and uncovering underlying arterial anatomic defects. None were treated definitively by endoluminal measures due to an inability to resolve the underlying anatomic defects. However, 2 of 5 cases (40%) went on to a successful surgical revascularization and represent successful long-term outcome of transcatheter thrombolysis followed by definitive surgical revascularization. We conclude that, definitive endoluminal success cannot be achieved without resolving associated, and possibly instigating, underlying arterial anatomical defects. However, reestablishing flow to the graft can unmask underlying lesions as well as asses surrounding vasculature thus providing anatomical information for a more elective, better planned and definitive surgical revision.

Endoluminal Management of Arterioportal Fistulae in Liver Transplant Recipients: A Single-Center Experience

Transcatheter embolization of arterioportal fistulae in liver transplant recipients is restricted to symptomatic arterioportal fistulae. Angiograms of liver transplant recipients from a single university medical center were retrospectively reviewed. Hemodynamically significant arterioportal fistulae were defined as those exhibiting opacification of the main portal vein of the transplanted hepatic graft or its first order branch with or without portal venous changes by Doppler ultrasound imaging. Six arterioportal fistulae were found. Doppler ultrasound imaging detected 50% of all arterioportal fistulae and all 3 hemodynamically significant arterioportal fistulae. Three successful embolizations were performed. Follow-up (37 to 67 months) demonstrated patent hepatic arteries and no parenchymal ischemic changes with graft preservation. High-throughput arterioportal fistulae may require larger intrahepatic artery branch embolization. There is a window of opportunity for embolizing significant arterioportal fistulae before their progression to large symptomatic, high through-put arterioportal fistulae with their added risk of ischemic changes before and after embolization.

Current Status of Clot Removal for Acute Pulmonary Embolism

Acute pulmonary embolism (PE) continues to carry a high mortality if not recognized early and treated aggressively. Rapid recognition and diagnosis remains the mainstay of all efforts. Risk stratification early is paramount to guide therapy and achieve successful outcomes. Pulmonary emboli can generally be classified as massive, submassive, or stable. Fibrinolysis and/or surgical embolectomy are recommended for the treatment of the patient with massive PE to rescue the patient and restore hemodynamic stability. Current trials support an aggressive approach. In submassive PE, determination of right ventricular (RV) strain by echocardiography and biomarker assessment (troponin and B-type natriuretic peptide) identify patients who can benefit from catheter-directed therapy with the therapeutic intent of achieving a rapid reduction of RV afterload, prevention of impending hemodynamic collapse and prolonged in-hospital and outpatient survival. Current trials have not shown long-term benefit for this approach to date, and thus, this therapy should only be offered to select patients. Stable PE can be treated using both an inpatient and an outpatient approach, based on the available infrastructure. Therapy for PE continues to evolve and stratification of risks and benefits remain the key to implementation of invasive strategies.

Objective performance goals after endovascular intervention for critical limb ischemia

OBJECTIVE

During the last decade, primary endoluminal therapy for critical limb ischemia (CLI), assessed as rest pain and tissue loss of the lower extremity, has significantly increased. Reporting of patient-centered outcomes using the new Society for Vascular Surgery objective performance goals (OPGs) has been limited. This study examined the OPGs for infrainguinal endovascular management of CLI.

METHODS

A prospective database of patients undergoing endovascular treatment of the lower extremity for CLI between 2000 and 2011 was queried. Evaluated were clinical efficacy (absence of recurrent symptoms, maintenance of ambulation and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (MALEs; above-ankle amputation of the index limb or major reintervention - new bypass graft, jump/interposition graft revision).

RESULTS

A total of 728 patients (60% male; age, 68 ± 14 years) underwent lower extremity interventions for CLI (66% tissue loss); of these, 39% had superficial femoral artery and tibial interventions. Diabetes mellitus was present in 71%, hyperlipidemia in 64%, and chronic renal insufficiency in 37%. Technical success was 96%. The overall rate at 30 days of major adverse cardiovascular events (MACEs) was 3% and MALEs was 12%. At 5 years, clinical efficacy was (mean ± standard error of the mean) 42% ± 5%, amputation-free survival was 41% ± 7%, and freedom from MALEs was 51% ± 4%. Clinical efficacy was significantly different in those presenting with rest pain and tissue loss and in the anatomic high-risk group compared with the clinical high-risk group, and both were worse compared with the group without clinical or high-risk criteria.

CONCLUSIONS

Endoluminal therapy for CLI is associated with early low MACE rates but high MALE rates. When the key outcome of amputation free survival is considered, predictors of a better outcome were absence of current smoking, a lower modified Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT III) amputation risk score, better preoperative ambulation status, lower MACEs, and discharge disposition to home. The presence of tissue loss and anatomic risk factors negatively affect outcomes. Longer-term outcomes after endovascular intervention for CLI remain relatively poor, with <40% success in objective performance outcomes at 5 years.

Case Report: En Bloc Resection of Pancoast Tumor with Adjuvant Aortic Endograft and Chemoradiation

"Pancoast" tumors frequently require a multidisciplinary approach to therapy and are still associated with high morbidity and mortality. Due to their sensitive anatomic location, complex resections and chemoradiation regimens are typically required for treatment. Those with signs of aortic invasion pose an even greater challenge, given the added risks of cardiopulmonary bypass for aortic resection and interposition. Placement of an aortic endograft can facilitate resection if the tumor is in close proximity to or is invading the aorta. Prophylactic endografting to prevent radiation-associated aortic rupture has also been described. This case describes a 60-year-old female who presented with a stage IIIa left upper lobe undifferentiated non-small-cell carcinoma encasing the subclavian artery with thoracic aorta and bony invasion. Following carotid-subclavian bypass with Dacron, en bloc resection of the affected lung, ribs, and vertebral bodies was performed. The aorta was prophylactically reinforced with a Gore TAG thoracic endograft prior to adjuvant chemoradiation. The patient remains disease-free at more than 5 years follow-up after completing her treatment course. Endovascular stenting with subsequent chemoradiation may prove to be a viable alternative to palliation or open operative management and prevention of aortic injury during tumor resection and/or adjuvant therapy in select patients with aortic involvement.

Outcomes of Isolated Tibial Endovascular Interventions for Tissue Loss in CLI Patients on Hemodialysis

PURPOSE

To compare the objective performance goals (OPGs) and patient-centered outcomes of isolated tibial interventions in patients with tissue loss who were on hemodialysis (HD) to patients with tissue loss who were not on HD.

METHODS

Interrogation of a prospectively maintained database identified 242 critical limb ischemia (CLI) patients who underwent isolated tibial interventions for tissue loss in a single limb between 2007 and 2012. The 78 patients (mean age 66±12 years; 44 men) on HD were compared with 164 patients (mean age 50±13 years; 82 men) who were not on HD. There was an equal distribution of the tibial vessels treated; 152 (63%) patients had more than one treated tibial vessel. Patient-centered outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and no major amputation), amputation-free survival (AFS), and freedom from major adverse limb events (MALE) were evaluated. The Society for Vascular Surgery OPGs were defined at 30 days and 1 year.

RESULTS

The 30-day major adverse cardiac events was significantly higher (p=0.004) in the HD group (5, 5%) compared with the no-HD group (0%), but both remained under the stated OPG of ≤10%. The 30-day MALE rates were significantly higher than the stated ≤9% OPG at 13% and 18% for the no-HD and HD groups, respectively. At 1 year, the rates for AFS, freedom from MALE, limb salvage, and survival did not achieve the stated Society for Vascular Surgery OPGs in the HD group. Clinical efficacy was 61% and 25% at 3 years for the no-HD and HD groups, respectively (p<0.01). Overall, AFS was 54% and 22% and freedom from MALE was 56% and 27% at 3 years for the no-HD and HD groups, respectively (both p<0.01).

CONCLUSION

Tibial intervention for tissue loss in patients on HD is a valid treatment option but is associated with a high MALE rate. Three-year outcomes remain relatively poor, with <25% success in terms of clinical efficacy and AFS.

Early Experience With a Novel Hybrid Vascular Graft for Hemodialysis Access Creation in Patients With Disadvantaged Anatomy

Purpose: To describe the use of the Hybrid vascular graft in disadvantaged anatomy for hemodialysis access creation and compare outcomes to standard-wall polytetrafluoroethylene (PTFE) grafts. Methods: In a retrospective analysis, 25 patients (mean age 65±14 years; 13 men) who received the Hybrid graft were compared with 35 contemporaneous patients (mean age 63±12 years; 20 men) who received a standard PTFE graft for hemodialysis access over a 2-year period. Criteria for Hybrid graft placement were (1) exhausted or inadequate peripheral veins for arteriovenous fistula (AVF) creation and concomitant small target veins that precluded conventional PTFE graft placement, (2) previous graft anastomosis or a stent in the venous target at the level of the axilla, or (3) failed brachial-basilic or brachial-brachial upper arm transposition AVF with a small target vein at the axilla. Efficacy, anatomic and clinical considerations, and technique were reviewed; patency rates, complications, and reinterventions were examined. Results: Technical success was achieved in all cases, and all grafts were usable for hemodialysis. Seven of 25 Hybrid patients required stent-graft extensions and 3 patients required angioplasty to improve venous outflow at the time of Hybrid graft insertion. Three of 35 standard PTFE graft patients required angioplasty to improve venous outflow at the time of graft insertion. There was no perioperative mortality or procedure-related morbidity in either group. Median follow-up was 21 months. The patient survival estimate was 66% at 2 years. Estimated primary patency (24% vs 18%, p>0.05), assisted primary patency (34% vs 28%; p>0.05), and secondary patency rates (40% vs 38%, p≥0.05) at 24 months were equivalent for Hybrid vs PTFE grafts, respectively. Venous hypertension was not a complication following Hybrid graft implantation but was seen in 2 patients with the standard PTFE graft. Conclusion: The Hybrid graft offers a safe, technically effective alternative for patients with disadvantaged anatomy requiring hemodialysis access and has comparable outcomes to standard PTFE grafts. Further clinical experience and long-term data are required for determining the proper utility of this device in chronic dialysis-dependent patients.

Endovascular management of early lung transplant-related anastomotic pulmonary artery stenosis

PURPOSE

To report the safety and short-term efficacy of endovascular interventions for symptomatic lung transplant-related anastomotic pulmonary artery stenosis (PAS).

MATERIALS AND METHODS

From February 2008 to December 2011, 354 lung transplants were performed. Pulmonary arteriography was performed in 19 patients (63% men; age, 57 y ± 21, mean ± SD; seven double-lung transplants) because of respiratory decompensation (mean 6.7 mo after transplant). Seven arteriograms were normal, and 12 showed significant PAS. One patient (5%) underwent angioplasty alone, and 11 patients (57%) underwent stent placement.

RESULTS

All patients underwent general anesthesia, and femoral access was used for the intervention. Technical success was 100% in the 12 patients treated. Symptoms improved in all patients who underwent intervention, with resolution in 11 of 12 (92%). There were no major or minor complications. Three patients (16%) had recurrent symptoms after discharge secondary to chronic rejection or pneumonia. Two patients died as a result of sepsis and multiorgan failure at 2 days and 14 days, respectively, after undergoing only pulmonary arteriography. In-stent stenosis occurred in 1 (9%) patient who required additional stent placement. During a mean follow-up period of 11 months, the remaining stents were patent, and the patients were asymptomatic.

CONCLUSIONS

Endovascular stent placement provides an alternative to open repair for transplant-related anastomotic PAS. It has low mortality and morbidity rates, and it has shown excellent short-term functional and anatomic outcomes.

Open arterial revascularization of the critically ischemic foot using arterial homograft

BACKGROUND

Revascularization alternatives for patients with critical limb ischemia and without adequate autogenous vein remain challenging. We reviewed our experience with the use of arterial homograft as a conduit for limb salvage in patients with limb ischemia and active lower extremity infections.

METHODS

A retrospective review of patients who underwent open arterial revascularization of the lower extremity with cryopreserved femoral artery homograft for the treatment of symptomatic critical limb ischemia (i.e., foot ulceration, infection, or gangrene) during an 18-month period was performed. Relevant clinical variables and treatment outcomes were analyzed. Clinical success was defined as limb salvage for one year, patency of the reconstruction, and wound healing.

RESULTS

Thirteen patients (5 men; average age 71 +/- 83 years, range 51-87 years) were treated during this study period. Treatment indications included 10 (77%) foot ulcerations, 2 (15%) critically ischemic limbs without ulceration, and 1 (8%) infected polytetrafluoroethylene bypass graft with acute occlusion and limb ischemia. A femoral below-the-knee popliteal bypass was performed in 4 (1%), femoral to anterior tibial artery in 4 (31%), femoral to posterior tibial artery in 3 (23%), and femoral to peroneal artery in 2 (15%). All 13 limbs were preserved. Minor amputations were performed in 6 patients, 2 underwent toe amputations and 4 patients had a trans-metatarsal amputation. The cumulative patency rate at 6, 9, and 18 months was 92.3%, 70.3%, and 58.6%, respectively.

CONCLUSION

Open arterial revascularization with arterial femoral homograft is an acceptable treatment method in patients with critical limb ischemia and active infection in whom autogenous vein is not available or the use of a synthetic conduit is not possible.

Renal interventions during endovascular aneurysm repair

Renal insufficiency is a risk factor for mortality and morbidity during endovascular aneurysm repair. Multiple changes in practice have occurred to mitigate renal injury and renal dysfunction. Transrenal fixation does carry an increased risk of a decline in renal function in the medium term. Renal stenting for athero-occlusive disease during endovascular aneurysm repair needs careful consideration, as indications have changed and there are unexpected consequences with early vessel occlusion. The growing number of renal interventions during complex endovascular aneurysm repair with the advent of chimney snorkel/periscope techniques and the introduction of fenestrated grafts has shown the resilience of the intervention with relatively low renal issues (approximately 10%), but has also illustrated the need for additional device development.

Evaluating and treating venous outflow stenoses is necessary for the successful open surgical treatment of arteriovenous fistula aneurysms

BACKGROUND

Arteriovenous fistula (AVF) aneurysms (AVFAs) can lead to skin erosion, bleeding, difficult access while on hemodialysis, and poor cosmetic appearance. We reviewed our experience in treating patients with aneurysmal dilatation of their AVF.

METHODS

We reviewed clinical data of 48 patients (37 men; overall mean age, 55 years; range, 28-85 years) with an AVFA who underwent treatment during a 30-month period. Relevant clinical variables and treatment outcomes were analyzed.

RESULTS

All patients underwent a fistulogram, and 90% required percutaneous angioplasty to improve outflow. Fifty-six percent of patients had one stenotic outflow lesion, and 44% had at least two tandem outflow stenoses that required treatment. Open repair with aneurysmorrhaphy was performed in one stage in 64% of patients and in two stages in 36%. A tunneled hemodialysis catheter was required in 11 patients (23%) until the surgically repaired AVF was ready for use again, comprising 10 patients treated with single-stage surgery and only one patient in the staged group. All AVFAs were effectively treated, and patients were able to maintain functional use of their access when healed.

CONCLUSIONS

There is a high association of venous outflow stenoses and AVFA. Comprehensive therapy should encompass treatment of any venous outflow stenoses before open AVFA repair. A two-stage repair may decrease tunneled hemodialysis catheter use in patients with multiple aneurysms.