Michalak, Gregory

Background: The superficial femoral artery and medial thigh region has been an underused donor site for perforator flaps. This study evaluated perforasomes of the superficial femoral artery and its principal branches to review the clinical applications for locoregional reconstruction. Methods: Twenty-six fresh cadaveric lower extremities were dissected. Perforator size and anatomical course from the superficial femoral artery, descending genicular artery, and saphenous artery branch were documented. Perforators were selectively injected with iodinated contrast to assess vascular territories using computed tomography. A retrospective chart review was conducted on consecutive patients (2014 to 2015). Results: One hundred thirty perforators were mapped in the medial thigh region. Eleven extended medial thigh perforator flaps and 15 hemicircumferential flaps were harvested. The mean distance from the joint line was 16.7 ± 7.3 cm. Perforators arose from the superficial femoral artery (62 percent), saphenous artery branch (23 percent), and descending genicular artery (15 percent). Superficial femoral artery perforators were located around the mid and proximal thigh region (p < 0.001). The median perforasome surface area was 244 cm2, representing 36 percent in hemithigh flaps with preferential filling in the anteromedial region. Proximal perforasomes were the smallest. Perforasome areas based on vessel origin were comparable; however, saphenous artery perforators had a broader perforasome compared with descending genicular (p = 0.01) and superficial femoral artery perforators (p = 0.04). Six clinical case examples were presented for knee, thigh, and lower leg reconstruction. Conclusions: The superficial femoral artery or its branches can provide nontraditional reconstructive perforator flap options in regional reconstruction. They can be simple to harvest using a free-style approach, do not require preoperative imaging, offer a one-stage reconstructive method with low morbidity, and obviate the need for microsurgery or muscle flaps.

Acute liver failure (ALF) is a catastrophic condition that can occur after major liver resection. The aim of this study was to determine the effects of the spheroid reservoir bio‐artificial liver (SRBAL) on survival, serum chemistry, and liver regeneration in posthepatectomy ALF pigs. Wild‐type large white swine (20 kg‐30 kg) underwent intracranial pressure (ICP) probe placement followed by 85% hepatectomy. Computed tomography (CT) volumetrics were performed to measure the extent of resection, and at 48 hours following hepatectomy to assess regeneration of the remnant liver. Animals were randomized into three groups based on treatment delivered 24‐48 hours after hepatectomy: Group1—standard medical therapy (SMT, n = 6); Group2—SMT plus bio‐artificial liver treatment using no hepatocytes (0 g, n = 6); and Group3—SMT plus SRBAL treatment using 200 g of primary porcine hepatocyte spheroids (200 g, n = 6). The primary endpoint was survival to 90 hours following hepatectomy. Death equivalent was defined as unresponsive grade 4 hepatic encephalopathy or ICP greater than 20 mmHg with clinical evidence of brain herniation. All animals in both (SMT and 0 g) control groups met the death equivalent before 51 hours following hepatectomy. Five of 6 animals in the 200‐g group survived to 90 hours ( P < 0.01). The mean ammonia, ICP, and international normalized ratio values were significantly lower in the 200‐g group. CT volumetrics demonstrated increased volume regeneration at 48 hours following hepatectomy in the 200‐g group compared with the SMT ( P < 0.01) and 0‐g (P < 0.01) groups. Ki‐67 staining showed increased positive staining at 48 hours following hepatectomy ( P < 0.01). Conclusion: The SRBAL improved survival, reduced ammonia, and accelerated liver regeneration in posthepatectomy ALF. Improved survival was associated with a neuroprotective benefit of SRBAL therapy. These favorable results warrant further clinical testing of the SRBAL.