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Background: The lumbar region has been scarcely explored as a donor site for free tissue transfer or as a free flap recipient site. The lumbar integument provides a versatile prospective flap site, with a potentially well-concealed scar. Similarly, defects of this region can require recipient vessels that may be difficult to identify. Although lumbar artery perforators have been described, the reliability of perforators in this region remains questionable. Methods: An anatomical study was undertaken combining both cadaveric and in vivo analysis of the lumbar vessels. The cadaveric component comprised both dissection and angiographic studies in fresh and embalmed cadavers (36 lumbar regions in 18 cadavers), and the clinical study comprised a computed tomographic angiographic study (44 sides in 22 patients) and an operative case report. Results: Perforators were shown to arise from all eight lumbar arteries to enter the lumbar integument, with their size, location, and course described. Lower lumbar perforators were more often septocutaneous and of larger caliber. A case in which the fourth lumbar artery and concomitant vein were used as free flap recipient vessels is described, the first such reported case in the literature. Conclusions: Improving the incidence of identifying lumbar perforators of large caliber and with a septocutaneous course can be achieved by selecting lower lumbar vessels, or with the use of preoperative computed tomographic angiography. Computed tomographic angiography can successfully identify the location, size, and course of lumbar artery perforators and can aid flap design. Lumbar artery perforators are highly useful for both donor and recipient vessels in free flap surgery.

BACKGROUND: The anterolateral thigh (ALT) flap has become increasingly popular due to its versatility and minimal donor site morbidity. Its major limitation has been uncertainty in predicting perforator anatomy, with the occasional absence of suitable perforators and high variability in their size and course. The variability of this anatomy has not been adequately explored previously. METHODS: A cadaveric study was undertaken, in which 19 thighs (from 10 fresh cadavers) underwent contrast injection and angiographic imaging. Anatomical variations of the vasculature were recorded. A clinical study of 44 patients undergoing ALT flap reconstruction was also undertaken. Perforator anatomy was described in the first 32 patients, and the subsequent 12 patients underwent computed tomography angiography with a view to predicting individual anatomy and improving operative outcome. RESULTS: Cadaver angiography was able to highlight and classify the variations in arterial anatomy, with four patterns observed and marked variability between cases. In 32 patients undergoing ALT flaps without preoperative CT angiography (CTA), five patients (16%) did not have any suitable perforators from the descending branch of the lateral circumflex femoral artery. By selecting the limb of choice with preoperative CTA, the incidence of flap unsuitability was reduced to 0%. Comparing CTA with Doppler, CTA was more accurate (sensitivity 100%) and provided more information. CONCLUSION: The perforators supplying the ALT flap show significant variability in location and course, with the potential for unsuitable perforators limiting flap success. Preoperative CTA can demonstrate the vascular anatomy and can aid perforator selection and operative success.

The deep inferior epigastric artery perforator (DIEP) flap aims to reduce donor-site morbidity by minimizing rectus muscle damage; however, damage to motor nerves during perforator dissection may denervate rectus muscle. Although cadaveric research has demonstrated that individual nerves do not arise from single spinal cord segments and are not distributed segmentally, the functional distribution of individual nerves remains unknown. Using intraoperative nerve stimulation, the current study describes the motor distribution of individual nerves supplying the rectus abdominis, providing a guide to nerve dissection during DIEP flap harvest.Twenty rectus abdominis muscles in 17 patients undergoing reconstructive surgery involving rectus abdominis (DIEP, transverse rectus abdominis musculocutaneous, or vertical rectus abdominis musculocutaneous flaps) underwent intraoperative stimulation of nerves innervating the infraumbilical segment of the rectus. Nerve course and extent of rectus muscle contraction were recorded.In each case, three to seven nerves entered the infraumbilical segment of the rectus abdominis. Small nerves (type 1) innervated small longitudinal strips of rectus muscle, rather than transverse strips as previously described. There was significant overlap between adjacent type 1 nerves. In 18 of 20 cases, a single large nerve (type 2) at the level of the arcuate line supplied the entire width and length of rectus muscle.Nerves innervating the rectus abdominis are at risk during DIEP flap harvest. Small, type 1 nerves have overlapping innervation from adjacent nerves and may be sacrificed without functional detriment. However, large type 2 nerves at the level of the arcuate line innervate the entire width of rectus muscle without adjacent overlap and may contribute to donor-site morbidity if sacrificed.

In free flap reconstruction and replantation surgery, prolonged ischemia time may lead to flap or replantation failure. The aim of the study was to investigate the effects of hypothermic flap ischemia or remote ischemic perconditioning (RIPER) during normothermic ischemia on acute inflammation of musculocutaneous flaps subjected to ischemia-reperfusion injury.In 24 pigs, a musculocutaneous latissimus dorsi flap was dissected and subjected to 4 hours of arterial ischemia and 7 hours of reperfusion. The animals were allocated into two experimental groups: hypothermic flap ischemia at 4°C (n = 8) or normothermic flap ischemia with RIPER (n = 8), and one control group with normothermic flap ischemia (n = 8). The hypothermic ischemic flaps were cooled in a basin with fresh water and ice. RIPER was initiated 1 hour before reperfusion, by inducing three 10 min cycles of hind limb ischemia with a tourniquet, each separated by 10 min of reperfusion. Acute inflammation was described by inflammatory cytokine secretion (IL-1β, IL-6, IL-10, IL-12p40, and TNF-α) from the flap during reperfusion, and by quantitative determination of macrophages in flap biopsies of dermis, subcutaneous tissue, and skeletal muscle following reperfusion.No significant differences were found between normothermic and hypothermic flap ischemia in inflammatory cytokine secretion. However, the IL-6 secretion was significantly reduced in the RIPER group compared with the control group at 5 hours of reperfusion (P = 0.036), and in the RIPER group compared with the hypothermic ischemia group at 3 (P = 0 0.0063), 5 (P = 0.0026), and 7 hours of reperfusion (P = 0.028). The IL-12p40 secretion was significantly reduced in the RIPER group compared with the control group (P = 0.0054) as well as the hypothermic ischemia group (P = 0.028) at 5 hours of reperfusion. No significant difference was found among groups in macrophage infiltration.RIPER reduced IL-6 and IL-12p40 secretion during reperfusion of porcine musculocutaneous flaps, when compared with hypothermic ischemic flaps and normothermic ischemic flaps without RIPER. © 2016 Wiley Periodicals, Inc. Microsurgery 37:148-155, 2017.