Creating reverse flow arteriovenous fistulas with a forearm cannulation target.

BACKGROUND: Establishing a forearm arteriovenous fistula (AVF) offers preferred cannulation sites and preserves proximal access opportunities. When a radiocephalic AVF at the wrist is not feasible and the upper arm cephalic and median cubital veins are inadequate, an AV graft or more complex access procedure is often required. Creating a retrograde flow forearm AVF (RF-AVF) is a valuable alternative where the mid-forearm median antebrachial or cephalic vein is adequate, offering forearm cannulation zones with AVF outflow through deep and superficial collaterals. We report our technique and results. METHODS: We retrospectively reviewed our vascular access data base of consecutive patients during an 11-year study period where a RF-AVF established the only available cannulation target in the forearm. In addition to physical examination, all patients had ultrasound vessel mapping. RESULTS: A forearm access was established with a RF-AVF as the only opportunity for cannulation in 48 patients. Ages were 14-86 years (median = 62 years). Forty-four percent female, 63% diabetic, 13% obese, and 29% had previous access operations. Inflow was proximal radial artery in 47 individuals and one proximal ulnar. Nine AVFs (19%) failed at 2-66 months (median 14 months). One RF-AVF was ligated due to arm edema. Follow-up was 2-111 months (median = 23.5 months). Primary and cumulative patency rates were 62% and 91% at 12 months, and 46% and 85% at 24 months. Five patients were lost to follow-up with functioning RF-AVFs (mean 41 months). Twenty-three patients (48%) died during F/U of causes unrelated to access procedures (mean 25 months). CONCLUSIONS: Establishing a reverse flow forearm AVF offers a successful autogenous access option in the forearm for selected patients with an inadequate distal radial artery and/or cephalic vein at the wrist, avoiding more complex or staged procedures and preserving upper arm sites for future use. A proximal radial artery inflow procedure is recommended.

Autogenous Vascular Access in American Indians.

BACKGROUND: American Indians (AI) or Alaska Natives, or in combination with another race, comprised 6.8 million individuals in 2010 and the population is expected to exceed 10 million in the current census. Diabetes is more common in AIs than in other races in the United States and is responsible for 69% of new onset end stage renal disease in AI patients. The incidence of obesity is also higher among AIs. As both diabetes and obesity make creating a successful autogenous vascular access more challenging, we reviewed our experience creating arteriovenous fistulas in AI patients. METHODS: Our vascular access database was reviewed for consecutive new AI patients undergoing creation of a hemodialysis vascular access during a 10-year period. Each patient underwent ultrasound vessel mapping by the operating surgeon in addition to history and physical examination. The goal for initial cannulation was 4-6 weeks after access creation. Minimal AVF flow volume for cannulation was 500 mL/min with an outflow vein diameter of 6 mm. RESULTS: 235 consecutive new AI patients were identified. All patients had an autogenous access constructed. The median age was 56 years (range, 15-89 years). Diabetes was present in 85% and 42% were female. Obesity was noted in 27% of the patients and 37% had previous vascular access operations. Primary patency at 12 and 24 months was 62% and 46%, respectively. Cumulative patency at 12 and 24 months was 96% and 94%, respectively. Female gender and previous access operations were associated with lower primary (P = 0.002 and 0.02, respectively) and cumulative patency (P = 0.01 and 0.04, respectively). Obesity was associated with lower cumulative access patency (P = 0.02). Overall, 74% of the access operations used the radial or ulnar artery for AVF inflow. Distal radial artery inflow AVFs were associated with longer patient survival (P = 0.01) and individuals with proximal radial inflow had longer survival when compared to brachial artery AVFs. Previous access operations were associated with shorter patient survival (P = 0.04). CONCLUSIONS: Safe and functional arteriovenous fistulas can be created for American Indians despite a higher prevalence of vascular access risk factors such as diabetes and obesity.

Carotid endarterectomy in patients with high plaque.

BACKGROUND: Difficult cephalad exposure during carotid endarterectomy in patients with high plaque (HP) may lead to increased incidence of complications after carotid endarterectomy. We report on our experience of carotid endarterectomy in patients with HP. METHODS: This is a retrospective review of 1,233 consecutive patients who underwent carotid endarterectomy by a single surgeon at 2 teaching hospitals between January 1989 to December 2018. Group A consisted of patients with HP (n = 100) diagnosed by computed tomography angiography of the neck in 90, catheter-based arteriography in 8, and an unexpected finding during carotid endarterectomy in 2 patients. Group B consisted of 1,133 consecutive carotid endarterectomies with plaque ending in Zone 1 non-high plaque (nHP). RESULTS: Both groups were similar in age (70.9 ± 8.7 vs 70.3 ± 9.1, P = .53). There was a preponderance of male patients in the HP group (78.0% vs 66.1%, P = .02). Associated risk factors, including coronary artery disease, hypertension, diabetes, chronic obstructive pulmonary disease, and hyperlipidemia, were similar in both groups. Indications for carotid endarterectomy in HP patients include recent stroke (<8 weeks) in 15 patients (15.0%), transient ischemic attack in 23 patients (23.0%), and asymptomatic in 62 patients (62.0%). Three patients (3.0%) with HP required shunt placement compared with 10.9% in the nHP group (P = .009). Completion carotid arteriogram was performed in 6 patients. Perioperative stroke and mortality were similar in both groups. The incidence of cranial nerve injury was higher in the HP group. CONCLUSION: Most patients with HP can be diagnosed with computed tomography angiography of the neck or catheter-based arteriography. Shunt requirement in patients with HP is significantly lower than in the nHP group. Perioperative stroke and mortality in patients with HP undergoing carotid endarterectomy is similar to the nHP group; however, there is a higher incidence of permanent cranial nerve injury. Carotid artery stenting should be considered in cases in which carotid endarterectomy may be challenging, such as in patients with HP. Overall, our results demonstrate that carotid endarterectomy can be safely performed in patients with HP, however, at an increased risk of permanent cranial nerve injury.

Iatrogenic Major Venous Injury Is Associated with Increased Morbidity of Aortic Reconstruction.

BACKGROUND: Major venous injury during open aortic reconstruction though uncommon often result in sudden and massive blood loss resulting in increased morbidity and mortality. This study details the etiology, management, and outcome of such injuries. METHODS: A retrospective review of 945 patients (1981-2017) undergoing aortic reconstruction from 2 midsized (350 bed each) teaching hospitals was conducted. Seven hundred twenty-three patients (76.5%) underwent open abdominal aortic aneurysm (AAA) repair/iliac aneurysm repair, 222 patients (23.5%) underwent aortofemoral grafting (AFG). Patients sustaining major venous injury (sudden loss of more than 500 mL of blood) during major aortic reconstruction were studied. The number of units of packed red blood cells transfused, location of injured vessel, type of repair, postoperative morbidity, and mortality were collected in our vascular registry on a continuous basis. All patients identified with iliac vein/inferior vena cava/femoral vein injury had follow-up noninvasive venous examination of the lower extremities. RESULTS: Eighteen major venous injuries (1.9%) occurred during aortic reconstruction in 17 patients (1 patient had 2 major venous injuries): IVC (n = 4), iliac vein (n = 10), left renal vein (n = 4, this includes a posterior retroaortic renal vein injury n = 1). Of the 18 major venous injuries, 7 occurred during open AAA repair for ruptured AAA and another 9 occurred during repair of intact AAA (P = 0.001), 2 venous injuries occurred after AFG, and 1 after primary AFG (P = 0.05). Using multivariate regression analysis, periarterial inflammation had significant association with major venous injury (P < 0.001). The presence of associated iliac aneurysm with abdominal aortic aneurysm also increased the incidence of major venous injury during AAA surgery (P = 0.05). Two patients (11.8%) died, one from uncontrolled bleeding due to tear of right common iliac vein during ruptured AAA repair and second patient from disseminated intravascular complication following repair of ruptured AAA. Intraoperative transfusion requirements were 3-28 units, (median 8 units). Three of 9 (33%) surviving patients developed iliofemoral venous thrombosis following repair of iliac/femoral vein injury. CONCLUSIONS: Major venous injury during aortic reconstructions occurs more commonly during the repair of ruptured AAA and redo AFG. Following repair of iliac/femoral vein injury, surveillance for possible deep venous thrombosis by duplex imaging should be considered.