John A. LoGiudice

Pediatric tissue expansion: indications and complications.

Tissue expansion has become a major reconstructive modality in the past 30 years. Its application in the pediatric population has allowed the plastic surgeon to achieve functional and esthetic goals that were previously unobtainable. Tissue expansion is a major treatment modality in the management of giant congenital nevi and secondary reconstruction of extensive burn scars, allowing sensate tissue of similar color, texture, and thickness to be used to resurface the affected areas. One must be prepared for complications when using tissue expanders, however, because complications are inherent in the process of expanding skin utilizing repeated filling of implanted foreign bodies. Complication rates increase when serial expansion of the same tissues is performed repeatedly or if expanders are placed in the lower extremities. Outcomes are dependent on thorough planning, meticulous technique, close follow-up, and patient compliance. Tissue expansion has revolutionized plastic surgery in the last 30 years. This technique can be applied to a considerable breadth of reconstructive problems in the pediatric population. Tissue expansion has permitted the plastic surgeon to achieve the goals of reconstruction with tissue of similar color, texture, and thickness, with minimal donor site morbidity. Preservation of sensation in a durable flap has allowed the surgeon to achieve acceptable functional as well as esthetic goals simultaneously.

Ceramide Changes the Mediator of Flow-Induced Vasodilation from Nitric Oxide to Hydrogen Peroxide in the Human Microcirculation

Rationale: Mitochondrial-derived hydrogen peroxide (H2O2) regulates flow-induced dilation (FID) in microvessels from patients with coronary artery disease. The relationship between ceramide, an independent risk factor for coronary artery disease and a known inducer of mitochondrial reactive oxygen species, and FID is unknown. Objective: We examined the hypothesis that exogenous ceramide induces a switch in the mediator of FID from nitric oxide to H2O2. Methods and Results: Internal diameter changes of resistance arterioles from human adipose and atrial tissue were measured by video microscopy. Mitochondrial H2O2 production was assayed in arterioles using mito peroxy yellow 1. Polyethylene glycol–catalase, rotenone, and Mito-TEMPO impaired FID in healthy adipose arterioles pretreated with ceramide, whereas N&ohgr;-nitro-L-arginine methyl ester had no effect. Mitochondrial H2O2 production was induced in response to flow in healthy adipose vessels pretreated with ceramide, and this was abolished in the presence of polyethylene glycol–catalase. Immunohistochemistry demonstrated ceramide accumulation in arterioles from both healthy patients and patients with coronary artery disease. N&ohgr;-nitro-L-arginine methyl ester reduced vasodilation to flow in adipose as well as atrial vessels from patients with coronary artery disease incubated with GW4869, a neutral sphingomyelinase inhibitor, whereas polyethylene glycol–catalase had no effect. Conclusions: Our data indicate that ceramide has an integral role in the transition of the mediator of FID from nitric oxide to mitochondrial-derived H2O2 and that inhibition of ceramide production can revert the mechanism of dilation back to nitric oxide. Ceramide may be an important target for preventing and treating vascular dysfunction associated with atherosclerosis.

Efficacy of the morphine-prostigmin test for evaluating patients with suspected papillary stenosis.

The morphine-Prostigmin test (MPT) has been advocated as a diagnostic test for identifying patients with papillary stenosis. We studied 14 patients referred for possible papillary stenosis with the MPT and ERCP sphincter of Oddi manometry. The response to the MPT (symptoms, serum amylase/lipase values) was evaluated by multiple criteria. The MPT was also done on 6 volunteer control subjects. Operative evaluation of the sphincter of Oddi was obtained in 8 of the 14 patients. There was no correlation between the results of the MPT and ERCP manometry or operative findings. There was good correlation, however, between ERCP manometric findings and operative assessment of the sphincter of Oddi. Fifty percent of the volunteer subjects had a significantly positive enzyme response to the MPT. In our experience the MPT does not reliably detect patients with papillary stenosis.

The anterolateral thigh flap for groin and lower abdominal defects: a better alternative to the rectus abdominis flap.

Background: Historically, the mainstay of soft-tissue reconstruction in the groin and lower abdomen has been the anatomically consistent, easily elevated rectus abdominis flap, with variations. Insetting the rectus abdominis flap here requires creating an abdominal wall defect through which to pass the pedicle, which raises the risk of donor-site morbidity. Although popular as a free flap, the anterolateral thigh flap as a pedicled flap in the groin and lower abdomen has not been directly compared with the rectus abdominis flap. Methods: Retrospective record review was conducted on 39 patients who underwent groin or lower abdominal wall reconstruction (30 anterolateral thigh flap and 10 rectus abdominis flap procedures) to address oncologic defects, lymphadenectomy, and complications of vascular bypass. Patient demographics and comorbidities, flap characteristics, postoperative complications, and time to heal were compared. Results: All patients in both the anterolateral thigh and rectus abdominis flap groups healed at the flap recipient sites. Despite similar patient characteristics, wound cause was different between the groups, with more infected wounds being treated in the anterolateral thigh flap group. Early postoperative complication rates were similar in both groups. Anterolateral thigh flap patients had shorter time to healing, with lower rates of delayed (>30 days) postoperative complications compared with rectus abdominis flap patients. Six rectus abdominis flap patients developed delayed abdominal incisional hernias. No donor- or recipient-site complications were encountered in anterolateral thigh flap patients after 90 days. Conclusion: The pedicled anterolateral thigh flap is the preferred choice for reconstruction of wounds in the groin and lower abdomen. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Ectopic scalp replantation: A case report

Temporary ectopic implantation with secondary replantation at the anatomic site is useful in salvage of extremities or organs [Godina M, Bajec J, Baraga A. Salvage of the mutilated upper extremity with temporary ectopic implantation of the undamaged part. Plast Reconstr Surg 1986;78: 295-99; Chernofsky MA, Sauer PF. Temporary ectopic implantation. J Hand Surg [Am] 1990;15:910-14; Matloub HS, Yousif NJ, Sanger JR. Temporary ectopic implantation of an amputated penis. Plast Reconstr Surg 1994;93:408-12; Hallock GG. Transient single-digit ectopic implantation. J Reconstr Microsurg 1992;8:309-11; Graf P, Groner R, Horrl W. Temporary ectopic implantation for salvage of amputated digits. Br J Plast Surg 1996;47:174-77; Yousif NJ, Dzwierzynski WW, Anderson RC, et al. Complications and salvage of an ectopically replanted thumb. Plast Reconstr Surg 1996;97:637-40; Wang J-N, Tong Z-H, Zhang T-H, et al. Salvage of amputated upper extremities with temporary ectopic implantation followed by replantation at a second stage. J Reconstr Microsurg 2006;22:15-20]. Temporary ectopic implantation is usually considered due to poor conditions for replantation at the anatomic site. We report a case of near-total scalp avulsion treated by temporary implantation to the lower abdomen with secondary replantation.

Neural systemic impairment from whole-body vibration

Insidious brain microinjury from motor vehicle‐induced whole‐body vibration (WBV) has not yet been investigated. For a long time we have believed that WBV would cause cumulative brain microinjury and impair cerebral function, which suggests an important risk factor for motor vehicle accidents and secondary cerebral vascular diseases. Fifty‐six Sprague‐Dawley rats were divided into seven groups (n = 8): 1) 2‐week normal control group, 2) 2‐week sham control group (restrained in the tube without vibration), 3) 2‐week vibration group (exposed to whole‐body vibration at 30 Hz and 0.5g acceleration for 4 hr/day, 5 days/week, for 2 weeks), 4) 4‐week sham control group, 5) 4‐week vibration group, 6) 8‐week sham control group, and 7) 8‐week vibration group. At the end point, all rats were evaluated in behavior, physiological, and brain histopathological studies. The cerebral injury from WBV is a cumulative process starting with vasospasm squeezing of the endothelial cells, followed by constriction of the cerebral arteries. After the 4‐week vibration, brain neuron apoptosis started. After the 8‐week vibration, vacuoles increased further in the brain arteries. Brain capillary walls thickened, mean neuron size was obviously reduced, neuron necrosis became prominent, and wide‐ranging chronic cerebral edema was seen. These pathological findings are strongly correlated with neural functional impairments.

The effect of calcium modulating agents on peripheral nerve recovery after crush

After a nerve injury, calcium concentration in the intra-nerve fiber drastically increases. The purpose of our study was to test an implantable micro-osmotic pump to deliver medications to accelerate calcium absorption, thereby greatly improving nerve regeneration. Twenty-four SD rats were divided into four groups of six each: (1) Sham control: crush injury to sciatic nerve only; (2) Crush injury with a Nifedipine pump; (3) Crush injury with a Calcitonin pump; (4) Crush injury with a Saline pump. Each rats right sciatic nerve was crushed. The micro-osmotic pump was implanted in the neck, and the dripping tube was routed to the injured nerve. After four weeks of survival time, compound muscle action potential (CMAP), tetanic muscle force (TMF), myelinated nerve fiber area (NFA), nerve calcium concentration (NCC), and calcified spots (CS) were evaluated. The calcium absorption rate (CAR) was also determined. The order from highest to lowest recovery rate was Nifedipine>Calcitonin>Sham control>Saline. Differences among the groups were statistically significant (P<0.001, ANOVA test), and the difference between Nifedipine/Calcitonin and Saline/Sham control were all statistically significant (P<0.001, t-test). The correlation rate of NCC with CMAP/TMF and with NFA/CS and CAR were calculated to be 0.99 (all P<0.001, Pearsons Correlation). We conclude from this study that nerve regeneration strongly correlated with calcium absorption; our new data has shown greatly improved nerve functional recovery, and this can potentially be translated into clinical applications.

Serratus anterior in vivo contractile force study.

Background: A major limitation of functional muscle transfer for facial and intrinsic hand reanimation is the inability to predict the force that will be generated by the transplanted muscle. Methods: The authors studied the contractile force of the slips of the serratus anterior in situ in 10 patients and tested the gracilis muscle in four subjects as a control. Results: Mean contractile force generated by each serratus slip was 0.178 pound (range, 0.019 to 0.797 pound). This compares favorably with the maximum force generated by smiling (0.307 pound). Muscle strength correlated strongly with age (r = –0.805, p = 0.005). The lowest slip generated less force than those above it (0.133 pound versus 0.191 pound); this difference did not reach statistical significance. When the strength of the lowest slip is compared with the more superior slips as a percentage of total force generated by the slips (to compensate for the effect of age on muscle strength), the lowest slip was significantly weaker (18.6 percent of total force versus 25.5 percent of total force, p = 0.013). Mean contractile force generated by the gracilis was 0.963 pound, significantly different from that generated by a serratus anterior slip (p = 0.009). Conclusions: Each serratus slip could potentially be used to generate a separate force vector for facial reanimation. Further separation of the flap along preexisting fascial planes may allow generation of up to 10 independent force vectors, making the serratus anterior muscle flap an attractive option for facial reanimation and possibly intrinsic hand muscle reconstruction.

Calcitonin pump improves nerve regeneration after transection injury and repair

Introduction: After nerve injury, excessive calcium impedes nerve regeneration. We previously showed that calcitonin improved nerve regeneration in crush injury. We aimed to validate the direct effect of calcitonin on transected and repaired nerve. Methods: Two rat groups (n = 8) underwent sciatic nerve transection followed by direct repair. In the calcitonin group, a calcitonin‐filled mini‐osmotic pump was implanted subcutaneously, with a catheter parallel to the repaired nerve. The control group underwent repair only, without a pump. Evaluation and comparison between the groups included: (1) compound muscle action potential recording of the extensor digitorum longus (EDL) muscle; (2) tetanic muscle force test of EDL; (3) nerve calcium concentration; and (4) nerve fiber count and calcified spot count. Results: The calcitonin pump group showed superior recovery. Conclusions: Calcitonin affects injured and repaired peripheral nerve directly. The calcitonin‐filled mini‐osmotic pump improved nerve functional recovery by accelerating calcium absorption from the repaired nerve. This finding has potential clinical applications. Muscle Nerve 51: 229–234, 2015

Effect of calcitonin on cultured schwann cells: Calcitonin and Schwann Cells

Introduction: After nerve injury, calcium concentrations in intranerve fibers quickly increase. We have shown that functional recovery of injured nerves correlates with calcium absorption. A slight increase in calcium reduces the number of Schwann cells present. Calcitonin therapy greatly improves regeneration by accelerating calcium absorption. We examined the effect of adding calcitonin to higher concentration calcium media on cultured Schwann cells. Methods: The cells, isolated from intact sciatic nerves, were cultured with normal or higher concentration calcium media with or without calcitonin. Schwann cells were incubated with anti–S‐100, goat–anti‐mouse, and propidium iodide and then viewed through fluorescent light and phase‐contrast microscopy for observation and analysis. Results: The cells in each calcitonin‐containing medium showed many Schwann cells, however, the cells in the higher concentration calcium media showed fewer and more defective Schwann cells. Conclusion: These results show that calcitonin protects against the harmful effects of excessive calcium encountered in peripheral nerve injury. Muscle Nerve 56: 768–772, 2017