Innominate and Axillary Cannulation in Aortic Arch Surgery Provide Similar Neuroprotection.

BACKGROUND: Contemporaneous trends in cerebral protection during aortic arch surgery include moderate hypothermia (22°C-28°C) and continuous antegrade cerebral perfusion (ACP). Innominate artery cannulation is a simplified, alternative route for ACP; however, clinical outcomes have yet to be evaluated against the gold standard of axillary cannulation. METHODS: Between 2008 and 2015, 140 consecutive patients underwent hemiarch reconstruction with moderate hypothermia and continuous ACP at 2 institutions. Axillary cannulation was used in 74 patients (31.1% female, 64.8 ± 12.7 years) and the remaining 66 patients (24.2% female, 60.8 ± 10.5 years) had direct cannulation of the innominate artery for delivery of ACP. RESULTS: Although there were no statistically significant differences in complications, neurological events were almost twice as frequent in innominate (19.7%) than in axillary (10.8%; P = 0.142) whereas prolonged mechanical ventilation was much more common with axillary (17.6%) vs innominate (7.6%; P = 0.078). There were no mortalities in the axillary group and 1 in the innominate group (0% vs 1.5%; P > 0.471) and no statistically significant differences in any other postoperative complications or hospital length of stay. There was a reduction in total operating room time in the innominate group (axillary 454 ± 115 minutes, innominate 318 ± 125 minutes; P < 0.001), and in the matched subgroup analysis of patients who underwent Bentall and hemiarch reconstruction (axillary 456 ± 109 minutes, innominate 370 ± 106 minutes; P = 0.003). CONCLUSIONS: Axillary and innominate artery cannulation for ACP during proximal aortic arch reconstructive surgery resulted in similarly excellent neurological outcomes. Innominate artery cannulation might reduce total surgical time. Possible clinically relevant differences in neurological and respiratory complications require assessment in randomized controlled trials.

Direct innominate artery cannulation for selective antegrade cerebral perfusion during deep hypothermic circulatory arrest in aortic surgery.

OBJECTIVE: To demonstrate a novel, reproducible, and effective method of direct innominate artery cannulation using a 14 F pediatric venous cannula to establish antegrade cerebral protection (ACP) in patients undergoing aortic surgery that requires an open distal anastomosis or hemiarch replacement. METHODS: We reviewed prospectively gathered data on all patients who had undergone replacement of the ascending aorta or hemiarch with an open distal anastomosis using deep hypothermic circulatory arrest and direct innominate artery cannulation with a 14 F pediatric venous cannula at our institution. After central cannulation and cooling to 25 °C to 28 °C, all patients had ACP initiated by way of a direct innominate cannula placed over a guidewire. RESULTS: Fifty patients underwent direct innominate artery cannulation with our technique from 2010 to 2012. The operative mortality was 2% (n = 1), and the rates of neurologic morbidity were acceptable and similar to those with other methods of ACP delivery: stroke (2%, n = 1), seizure (0%, n = 0), and delirium (18%, n = 9). The mean operative time was 31 ± 9, 19 ± 5, 100 ± 39, 141 ± 39, and 259 ± 63 minutes for cooling, circulatory arrest, crossclamp, cardiopulmonary bypass, and total operative time, respectively. No local or arterial complications were observed. CONCLUSIONS: Direct cannulation of the innominate artery using a 14 F pediatric venous cannula is a simple, reproducible, safe, and effective technique for establishing ACP in patients undergoing aortic surgery that requires an open distal anastomosis or hemiarch replacement. This technique avoids the additional time and potential local complications associated with other established methods for delivering ACP, such as axillary cannulation.

Serologic evidence for exposure to Rickettsia rickettsii in eastern Arizona and recent emergence of Rocky Mountain spotted fever in this region.

During 2002 through 2004, 15 patients with Rocky Mountain spotted fever (RMSF) were identified in a rural community in Arizona where the disease had not been previously reported. The outbreak was associated with Rickettsia rickettsii in an unexpected tick vector, the brown dog tick (Rhipicephalus sanguineus), which had not been previously associated with RMSF transmission in the United States. We investigated the extent of exposure to R. rickettsii in the local area through serologic evaluations of children and dogs in 2003-2004, and in canine sera from 1996. Antibodies to R. rickettsii at titers > or = 32 were detected in 10% of children and 70% of dogs in the outbreak community and 16% of children and 57% of dogs in a neighboring community. In comparison, only 5% of canine samples from 1996 had anti-R. rickettsii antibodies at titers > or = 32. These results suggest that exposures to RMSF have increased over the past 9 years, and that RMSF may now be endemic in this region.