Protamine sulfate use during tibial bypass does not appear to increase thrombotic events or affect short-term graft patency.

OBJECTIVES: While the use of protamine sulfate as a heparin reversal agent has been extensively reviewed in patients undergoing carotid endarterectomy and coronary artery bypass grafting, there is a lack of literature on protamine's effects on lower extremity bypasses. The purpose of this study was to determine the risk of protamine sulfate dosing after tibial bypass on thrombotic or bleeding events, including early bypass failure. METHODS: We performed a retrospective review of our institutional database for patients undergoing primary distal peripheral bypass from January 2009 through December 2015 (contralateral bypass was considered to be a new primary bypass). Primary endpoints include composite thrombotic events (myocardial infarction, stroke, amputation at 30 days and patency less than 30 days) and composite bleeding events (bleeding or transfusion). RESULTS: A total of 152 tibial or peroneal bypasses in 136 patients with critical limb ischemia were identified. Of these, 78 (57.4%) patients received protamine sulfate intraoperatively and 58 (42.6%) did not. There were no differences in composite thrombotic or hemorrhagic outcomes. Protamine use had no effect on the rates of perioperative MI (9.0% versus 3.5%, p = 0.20), stroke (1.3% versus 1.7%, p = 0.83), or perioperative mortality (5.1% versus 3.5%, p = 0.64). There was no significant difference in composite post-operative bleeding events (20.7% versus 14.1%, p = 0.31) or composite thrombotic events (17.2% versus 18.0%, p = 0.91). Patients who received protamine undergoing bypass with non-autogenous conduit had significantly higher-recorded median operative blood loss (250 mL versus 150 mL, p = 0.0097) and median procedure lengths (265 min versus 201 min, p = 0.0229). No difference in 30-day amputation-free survival was noted (91.0% versus 91.4%, p = 0.94). Follow-up Kaplan-Meier estimation did not demonstrate a difference in 30-day patency (91.7% versus 88.5%, p = 0.52). CONCLUSIONS: Heparin reversal with protamine sulfate after tibial or peroneal bypass grafting is not associated with higher cardiovascular morbidity, bypass thrombosis, amputation, or mortality. Additionally, there was no statistically significant difference in post-operative bleeding or thrombosis complications for patients who did not receive protamine, although the findings are suggestive of a potential difference in a more adequately powered study. Our results suggest that protamine sulfate is safe for intraoperative use without increased risk of thrombotic complications or early tibial bypass graft failure.

The Use of Idarucizumab for Dabigatran Reversal in Clinical Practice: A Case Series.

PURPOSE: To describe the use of idarucizumab (Praxbind, Boehringer Ingelheim) in routine clinical practice at a large urban academic medical center. SUMMARY: Seven total doses of idarucizumab were administered to six unique patients from October 31, 2015, to October 31, 2016. The reversal agent was used in conjunction with local bleeding control measures, blood product transfusions, and acid-suppressive therapy. In 86% of cases, idarucizumab administration resulted in a successful cessation of bleeding by clinical assessment. Two patients expired due to coexisting conditions. Idarucizumab was administered to patients with normal baseline coagulation tests in 43% of cases. No adverse reactions related to idarucizumab were reported. CONCLUSIONS: Idarucizumab administration resulted in successful resolution of bleeding by clinical assessment. The therapy for acute bleeding with use of dabigatran (Pradaxa, Boehringer Ingelheim) remains supportive care, in addition to idarucizumab in cases of severe or uncontrolled bleeding. Development of institution-specific protocols and better guidance for using baseline coagulation tests are needed.

Acute Kidney Injury Risk and Contrast Volume in Intact Versus Ruptured Endovascular Aneurysm Repair in the Vascular Quality Initiative.

OBJECTIVE: Renal impairment after repair of ruptured abdominal aortic aneurysm has been associated with post-operative mortality. Acute kidney injury (AKI) risk specifically related to contrast administration in endovascular aneurysm repair (EVAR) for intact vs ruptured aneurysms has not been previously described. It was our objective to evaluate the risk of AKI and the association with contrast administration in EVAR for ruptured (rEVAR) and intact (iEVAR) aneurysm repair in the Vascular Quality Initiative (VQI). METHODS: Adult patients less than 90 years old undergoing EVAR in the VQI without prior abdominal aortic surgery or who were not actively on dialysis preoperatively were included. Patients immediately converted to an open repair were excluded. Patients were grouped by repair urgency, and patient and operative characteristics and outcomes compared. Univariable and multivariable analyses were performed to identify factors associated with the primary outcome of AKI. Survival was evaluated by Kaplan-Meier analysis. RESULTS: Of 38,775 EVAR patients identified, 86.5% underwent elective surgery for an intact aneurysm, 8.4% had urgent surgery for a symptomatic, intact aneurysm, and 5.1% had emergent repair for a ruptured aneurysm. Significant risk factors for AKI included contrast volume, a preoperative eGFR <30 mL/min, procedure urgency, COPD, congestive heart failure (CHF), and total procedure time. The factor most associated with AKI was aneurysm rupture prior to repair (OR 8.6, CI 7.2-10.3, P <.01). The association of contrast volume with the outcome was the least strong with a 4% increase in risk per 25 mL of contrast (OR 1.04, 95% CI 1.01-1.07). With the development of AKI, postoperative survival was reduced regardless of indication. CONCLUSIONS: Of all factors assessed, aneurysm rupture was the most and contrast volume the least associated with AKI after EVAR. Further studies should evaluate methods of preventing post-EVAR AKI.

A case of intra-arterial thrombolysis with alteplase in a patient with hypothenar hammer syndrome but without underlying aneurysm.

Hypothenar hammer syndrome is a cause of symptomatic ischemia of the hand secondary to the formation of aneurysm or thrombosis of the ulnar artery in the setting of a complete or incomplete palmar arch. Acute occlusive thrombus or embolus of the hand represents a complex problem that often may require immediate surgical intervention. We report a case of acute unilateral arterial hand ischemia requiring catheter-directed thrombolysis with Alteplase therapy in a patient with acute occlusive arterial thrombosis of the left ulnar artery. A catheter-directed thrombolytic regimen consisted of Alteplase 1 mg/h for 24 h, and heparin was infused through the sheath side arm at a rate of 500 units per hour for resolution of the thrombus and improvement in symptoms. A former truck driver presented with worsening pain and subsequent development of significant cyanosis with early gangrenous changes of the left second and third fingertips. He had significant callous of the hypothenar eminence and reported that his left hand was not only his "driving" hand but also a cane has been used in his left hand to ambulate. Initial angiogram revealed only ulnar artery occlusion at the wrist with reconstitution just distal to the hypothenar eminence. After 24 h of the initiation of thrombolysis, repeat angiography revealed resolution with a widely patent ulnar artery. His symptoms and the color of his digits immediately improved, and within a few months, his hand had normalized. The patient had no clinical sequelae of thrombolytic therapy. Catheter-directed thrombolytic therapy in situations of acute occlusive thrombus of the hand may provide a therapeutic option for patients with suspected hypothenar hammer syndrome. However, thrombolytic therapy carries risk of significant hemorrhagic complications. Before initiating therapy, careful judgment about the possibility for bleeding risk is required. This provides for a minimally invasive alternative to open surgical revascularization especially in the absence of underlying correctable anatomic defect such as aneurysm.