Reconstruction of mandibular defects involving the central segment with fibula osteoseptocutaneous free flap following ameloblastoma resection: Patient-reported outcomes.

OBJECTIVES: Mandibular defects involving the central segment are challenging. This study analyzes the impact of defect extent and reconstruction method on quality of life (QOL) and obstructive sleep apnea (OSA). MATERIALS AND METHODS: Twenty-nine ameloblastoma patients received segmental mandibulectomy involving the C-segment and immediate fibula free flap reconstruction were recruited. Defects: (C: 2, LC: 11, LCL: 19). Mean defect length: 8.79 cm (± 2.34). Inset: Low-single-barrel (n: 19), with secondary distraction osteogenesis (n: 8/19), high-single-barrel (n: 7), double barrel (n: 3). Patients were surveyed using University of Washington Quality of Life (UW-QOL) and Berlin risk of postoperative sleep apnea questionnaires. RESULTS: Flap failure: None. Mean follow-up: 109.6 ±â€¯92.8 months. UW-QOL: Physical function 91.83 (± 14.92); social function 90.17 (± 17.19). No statistical difference between C, LC, and LCL was found, but C group which received low-single-barrel had the lowest score in appearance and chewing domains. In health-related QOL (HR-QOL) compared with 1 month before cancer, 69% reported best results. "Appearance" was the most important issue for the past 7 days, followed by "Chewing," prevailing in LC and C groups that predominately reconstructed by low-single-barrel. Berlin score: 7 patients (4 LCL, 3 LC≥8 cm) were at high risk for postoperative OSA. CONCLUSION: "Like-with-like" reconstruction with immediate endosteal dental implants yields the best results. Inset of fibula bone could affect outcomes, favoring double-barrel or single-high-barrel inset. Appearance and chewing remain the main concerns, largely, in those with low-single-barrel inset and no dental restoration. After long/extensive LCL and LC mandibulectomies, postoperative OSA warrants further investigation, and modification of resection/reconstruction techniques.

Recommendations to Safeguard Reconstructive Microsurgeons Performing High-risk Operations during the COVID-19 Pandemic.

An unprecedented number of health care providers have been infected and many have died during the COVID-19 pandemic. Reconstructive microsurgeons from different surgical backgrounds often are involved in the care of known COVID-19 and high-risk patients. The need for a magnification loupe/microscope makes it difficult for them to wear recommended personal protection equipment, increasing the risk of exposure. Although advanced technologies are available, they have not been exploited effectively. To date, no safety guidelines are available for safe reconstructive microsurgical procedures in high-risk operations/known COVID-19 patients-particularly, to address operations risk and COVID-19 status of the patients, who would operate, how many should be involved, how to equip the surgeons for the procedure, when to operate as the procedure unfolds, how to adapt surgical techniques to reduce exposure risk, and can advanced technology be used to minimize exposure. A set of safety recommendations were thus developed based on literature review and firsthand knowledge of safety procedures during the COVID-19 pandemic. Current understanding of COVID-19 virology can optimize surgical team buildup and dynamics. Operating smaller teams (in a sequential style), minimizing the use of aerosols-generating devices, and modifying surgical plan and flap selection could aid in diminishing the risk of exposure and in conserving resources. Modifications in loupes design, and the combined wear of surgical mask and N95 respirators, and efficient use of "buddy system" could aid in protecting surgeons during donning and doffing. "Remote operating" is a novel concept of using a surgical robot to maximize surgeons' safety during COVID-19 pandemic.

Peripheral arterial disease: the role of extracellular volume measurements in lower limb muscles with MRI.

OBJECTIVES: Peripheral arterial disease (PAD) is characterised by arterial occlusion and fibrosis in the lower extremities. Extracellular volume matrix fraction (ECV) is a biomarker of skeletal muscle fibrosis, but has not been applied to the lower extremities with PAD. This study investigated the clinical feasibility of using ECV for calf muscle fibrosis quantification by comparing normal controls (NC) and PAD patients. METHODS: From October 2016 to December 2017, we recruited patients with PAD, and patients with head and neck cancer receiving fibular flap as NC group. All participants underwent magnetic resonance imaging (MRI) to determine the ECV of the calves and the differences between the NC and PAD groups. ECV was calculated from T1 values at steady-state equilibrium, defined as the point in time after contrast agent injection when the variance of T1 relaxation time in blood and muscle becomes less than 5%. RESULTS: A total of 46 patients (18 in the NC group and 28 in the PAD group) were recruited. Steady-state equilibrium was reached at 11-12 min after contrast agent injection. The NC group had significantly lower mean ECV than the PAD group (12.71% vs. 31.92%, respectively, p < 0.001). In the PAD group, the mean ECV was slightly lower in patients with collateral vessels than in those without (26.58% vs. 34.88%, respectively, p = 0.047). CONCLUSION: Evaluation of skeletal fibrosis in PAD using ECV is feasible. ECV can help identify PAD patients with collateral vessel formation and lay the foundation for future research in PAD management. KEY POINTS: • Steady-state equilibrium for ECV measurement of the lower limbs can be reached at around 11-12 min. • Quantification of lower limb muscle fibrosis by measuring ECV is clinically feasible and can be used to differentiate between patients with PAD and histologically proven normal controls. • ECV can differentiate PAD patients with or without visible collateral vessels, further expanding its role in identifying the presence of collateral supply in clinical decision-making.

Predicting Outcomes of Rat Vascularized Composite Allotransplants through Quantitative Measurement of Chimerism with PCR-Amplified Short Tandem Repeat.

Chimerism has been associated with the induction and maintenance of tolerance to vascularized composite allotransplants (VCA). Although most VCA studies have examined chimerism using flow cytometry, we proposed that precision in the measurement of chimerism may be better approximated when complimentary polymerase chain reaction (PCR) is applied to a specific short tandem repeat (STR). We identified a STR, D10Rat25, which exhibited a ~20 bp difference in length between two rat strains (BN and LEW) often utilized as the donor and recipient in many allotransplantation studies. D10Rat25 was PCR-amplified and quantified with capillary electrophoresis. With pure LEW and BN DNA, a standard curve was constructed to measure chimerism with good linearity. When applied to rat VCA, the relationship between systematic (in peripheral blood) or local (at specific organ/tissues) chimerism to allograft outcomes was noted. We found that peripheral chimerism was elevated by up to ~9% postoperative month 1 (POM 1) but then reduced regardless of the final VCA outcome. However, differences in VCA skin chimerism between early rejection and POM 1 (shown as ΔChimerismPOM1-ER) were notable with respect to VCA outcomes. ROC analysis identified the optimum cutoff value as 17.7%. In summary, we have developed a reliable method to quantify the percentage of BN cells/DNA in BN-LEW chimeras. The detection limit was characterized, and the acquired data were comparable with flow cytometry. This method can be applied to solid organ and composite tissue allotransplantation studies.

The Fibula Osteoseptocutaneous Flap: Concise Review, Goal-Oriented Surgical Technique, and Tips and Tricks.

The fibula osteoseptocutaneous flap is a workhorse flap for bone reconstruction. Mastery of the flap is essential for a rewarding reconstruction. However, there is no complete work on this versatile flap. The authors provide a concise review of the literature, address the myths and challenges associated with the flap, and describe their refined techniques for different reconstruction scenarios and possible anatomical variations.

The Battle Ground between Two Giants: Toe Transfer and Hand Allotransplantation.

A few severe hand injuries represent a gray zone for the reconstructive surgeon, for which autologous tissue transfer and allotransplantation can yield satisfactory results, but not without downsides or morbidity.This article is written to address the dilemma of application of both techniques in those selected cases.