Surgical Techniques Following Free Cartilage Grafting.

BACKGROUND: Reconstruction of surgical defects with free cartilage grafts poses unique challenges. OBJECTIVES: To characterize surgical techniques following free cartilage grafting. MATERIALS AND METHODS: A literature review was performed using the Embase, PubMed Medline, Cochrane Library, ClinicalTrials.gov , and Web of Science databases from inception to May 21, 2021. Studies describing free cartilage grafts harvested from the ear or nose under local anesthesia, specifically for reconstruction of facial surgical defects, were selected for inclusion. Only surgical defects resulting from tumor resection were included. RESULTS: In total, 34 studies involving 713 patients with 723 surgical defects met inclusion criteria. The mean age of patients was 63.3 ± 10.4 years. Free cartilage grafts were most commonly harvested from the ear (93.1%). The most common recipient site was the nose (90.3%), followed by the lower eyelid (6.7%) and ear (3.0%). CONCLUSION: Free cartilage grafts are an effective reconstructive option for patients with deep or cartilaginous defects that have compromised structural support on the nose, ear, or eyelid.

ACTA2 Mutation: Microsurgeon Beware!

Patients with the alpha actin 2 genetic mutation suffer early onset aneurismal and vascular-occlusive conditions due to dysfunctional smooth muscle contractility. Outcomes of free flap reconstruction in this patient population are unknown. Here we report the case of a 21-year-old woman with alpha actin 2 mutation who required decompressive hemicraniectomy following an acute stroke. The entire Cushing flap underwent necrosis, requiring debridement and exposing dura. This condition was treated with a free latissimus myocutaneous flap. The patient's post-operative course was complicated by venous thrombosis, requiring intra-flap tPA and revision of the venous anastomosis with a saphenous vein graft. Ultimately the distal 75% of the flap was lost, leaving the dura exposed. The patient's course was further complicated by multiple wound healing complications: large areas of necrosis of the latissimus and saphenous vein donor sites, the neck vessel recipient site, and the right hand after IV infiltration. She ultimately healed with a regenerative tissue matrix strategy. Reconstructive options with no or minimal donor site morbidity should be considered in patients with the alpha actin 2 mutation. We encourage further reporting of outcomes in these patients.

TMRpni: Combining Two Peripheral Nerve Management Techniques.

Amputee patients suffer high rates of chronic neuropathic pain, residual limb dysfunction, and disability. Recently, targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) are 2 techniques that have been advocated for such patients, given their ability to maximize intuitive prosthetic function while also minimizing neuropathic pain, such as residual and phantom limb pain. However, there remains room to further improve outcomes for our residual limb patients and patients suffering from symptomatic end neuromas. "TMRpni" is a nerve management technique that leverages beneficial elements described for both TMR and RPNI. TMRpni involves coaptation of a sensory or mixed sensory/motor nerve to a nearby motor nerve branch (ie, a nerve transfer), as performed in traditional TMR surgeries. Additionally, the typically mismatched nerve coaptation is wrapped with an autologous free muscle graft that is akin to an RPNI. The authors herein describe the "TMRpni" technique and illustrate a case where this technique was employed.

Pulley Release and Reconstruction With Acellular Dermal Matrix After Zone 2 Flexor Tendon Injury.

Zone 2 flexor tendon repair has been historically associated with poor outcomes, mainly due to stiffness. In an effort to minimize adhesions, accommodate flexor digitorum profundus and flexor digitorum superficialis bulk, and prevent bowstringing, we have developed a novel approach to flexor tendon repair that relies on aggressive flexor tendon pulley release and pulley reconstruction with acellular dermal matrix. This technique leverages the antiadhesive properties and high tensile strength of acellular dermal matrix to maximize gliding and prevent bowstringing. Here we describe the details of our technique and illustrate a case where this technique was employed.

Pyogenic Flexor Tenosynovitis Caused by Shewanella putrefaciens.

Flexor tenosynovitis is a surgical emergency due to the risk of tendon necrosis which can lead to subsequent amputation. We report a case of flexor tenosynovitis with Shewanella putrefaciens as the implicated organism, though the patient's mechanism of penetrating trauma did not involve a marine exposure. Shewanella are Gram negative bacilli associated with marine environments and have rarely been implicated in human disease. This patient presented with all four of Kanavel's signs and required open surgical irrigation and debridement; he was found to have purulence but no flexor tendon necrosis. This case emphasizes the importance of considering marine organisms as putative for flexor tenosynovitis, even if marine exposure does not occur at the time of the penetrating trauma. It also emphasizes the need to obtain a thorough patient history, especially in cases of infection, to assess for all possible environmental exposures.

Trainee Operative Autonomy in Plastic Surgery.

BACKGROUND: Appropriate, progressive trainee autonomy is critical for training competent plastic surgeons who are adequately prepared to enter independent practice. Evaluation and reporting of meaningful operative autonomy among trainees in plastic surgery are understudied. METHODS: Parallel survey instruments were developed using the Zwisch metric for progressive operative autonomy and distributed electronically to trainees and faculties in all accredited training programs. Trainees were queried about their operative autonomy in 17 core plastic surgery procedures, associated approach to logging cases, and perceived readiness to enter practice. Faculties provided assessment of their final-year trainees using the same metrics. RESULTS: Trainees in 28 programs and faculties in 35 programs participated. Final-year trainees reported the most operative independence with breast tissue expander reconstruction and carpal tunnel release and the least with facelift and rhinoplasty. A mean of 40% of final-year trainees reached supervision only autonomy in the procedures queried; none achieved this with rhinoplasty. Faculties identified the highest final-year trainee operative autonomy with botulinum toxin injection and burn excision and grafting; the least trainee independence was reported with rhinoplasty, cleft lip repair, and facelift. Faculty perception of final-year trainee autonomy was higher than that of trainees for 82% of procedures queried. CONCLUSIONS: Although plastic surgery trainees endorse gradual operative autonomy overall, a majority of final-year trainees do not perceive supervision only independence in the majority of core procedures queried. Faculties perceive higher trainee operative autonomy than trainees for most procedures. Discordant approaches to case logging were identified both among trainees and between trainees and faculties. Standardization may improve both progression and assessment of operative autonomy in plastic surgery training.

The Anterolateral Thigh-Medial Femoral Condyle Chimeric Flow-through Flap for Posttraumatic Wrist Arthrodesis.

Wrist arthrodesis in the setting of segmental bone loss can have high failure rates. Therefore, vascularized bone grafting has been advocated for select patients. Patients suffering concomitant large soft tissue loss present even greater challenge. To that end, we describe for the first time successful anterolateral thigh-medial femoral condyle chimeric flow-through flap for posttraumatic wrist arthrodesis and soft tissue coverage. This is a case report of a 19-year-old male laborer who suffered a large blast injury resulting in significant bone and soft tissue injury to the dominant right hand and wrist. After multiple debridements, there was a segmental bone defect from the distal radius and ulna to the metacarpal bases, as well as a 12×8 cm dorsal soft tissue defect. This was reconstructed with a anterolateral thigh-medial femoral condyle chimeric flow-through flap and concomitant wrist arthrodesis in a single stage. Besides a donor site thigh seroma, recovery was uneventful with clinical and radiographic evidence of fusion by >9 weeks postoperation.

An in vitro fluid dynamic study of pediatric cannulae: the value of animal studies to predict human flow.

A challenge to the development of pediatric ventricular assist devices (PVADs) is the use of the aortic cannulae attached to the devices. Cannulae used for pediatric application have small diameters and large pressure drops. Furthermore, during the development of the 12cc Penn State pediatric PVAD, particle image velocimetry (PIV) illustrated that hematocrit levels, through changes in blood viscoelasticity, affected the fluid dynamics. The objective of this study is to compare the fluid dynamics of a pediatric viscoelastic blood analog and a goat viscoelastic blood analog within the PVAD aortic cannula. Two acrylic models were manufactured to model the aortic cannula (6 mm and 8 mm diameters). PIV data was collected to examine the flow at the outlet of the VAD and in the aortic cannula at heart rates of 50 and 75 beats per minute (bpm). Three planes of data were taken, one at the centerline and two 1.5 mm above and below the centerline. Three more planes of data were taken orthogonal to the original planes. While a 75 bpm heart rate was used to represent normal operating conditions, a 50 bpm heart rate represented use of the PVAD during weaning. At 75 bpm, differences were evident between the two different fluids and the two models. Separation zones developed in the plane below the centerline for the higher hematocrit pediatric blood analog. This study raises question to the usefulness of animal testing results in regard to how well they predict the outcome of pediatric patients.

The influence of operational protocol on the fluid dynamics in the 12 cc Penn state pulsatile pediatric ventricular assist device: the effect of end-diastolic delay.

The success of adult ventricular assist devices (VADs), coupled with the high transplant waiting list mortality of infants (40%) has prompted Penn State to develop a pediatric version of the clinically successful adult device. Although the primary use of this device will be bridge-to-transplant, there has been sufficient clinical data to demonstrate the efficacy of VADs in a bridge-to-recovery setting. However, removing the patient from the device, a process known as weaning, demands operation of the device at a lower beat rate and concomitant increased risk for thromboembolism. Previous studies have shown that the interrelated flow characteristics necessary for the prevention of thrombosis in a pulsatile VAD are a strong inlet jet, a late diastolic recirculating flow, and a wall shear rate greater than 500/s. In an effort to develop a strong inlet jet and rotational flow pattern at a lower beat and flow rate, we have compressed diastole by altering the end-diastolic delay time (EDD). Particle image velocimetry was used to compare the flow fields and wall shear rates in the chamber of the 12 cc Penn State pulsatile pediatric VAD operated at 50 beats per minute using EDDs of 10, 50, and 100 ms. Although we expected the 100 ms EDD to have the best wall shear profiles, we found that the 50 ms EDD condition was superior to both the 10 and 100 EDD conditions, due to a longer sustained inlet jet.

The 12 cc Penn State pulsatile pediatric ventricular assist device: fluid dynamics associated with valve selection.

The mortality rate for infants awaiting a heart transplant is 40% because of the extremely limited number of donor organs. Ventricular assist devices (VADs), a common bridge-to-transplant solution in adults, are becoming a viable option for pediatric patients. A major obstacle faced by VAD designers is thromboembolism. Previous studies have shown that the interrelated flow characteristics necessary for the prevention of thrombosis in a pulsatile VAD are a strong inlet jet, a late diastolic recirculating flow, and a wall shear rate greater than 500 s(-1). Particle image velocimetry was used to compare the flow fields in the chamber of the 12 cc Penn State pediatric pulsatile VAD using two mechanical heart valves: Bjork-Shiley monostrut (BSM) tilting disk valves and CarboMedics (CM) bileaflet valves. In conjunction with the flow evaluation, wall shear data were calculated and analyzed to help quantify wall washing. The major orifice inlet jet of the device containing BSM valves was more intense, which led to better recirculation and wall washing than the three jets produced by the CM valves. Regurgitation through the CM valve served as a significant hindrance to the development of the rotational flow.

The 12 cc Penn State pulsatile pediatric ventricular assist device: flow field observations at a reduced beat rate with application to weaning.

Ventricular assist devices (VADs) have become a viable option for adult patients with end-stage heart failure during the bridge-to-transplant period and have recently shown promise in aiding in myocardial recovery. Because the number of available organs is insufficient, mechanical circulatory support systems such as VADs are also being developed for use in pediatric patients. During myocardial recovery, the system must be weaned from the patient to prepare for explant; for pulsatile devices, this often includes a reduction in flow rate, which can change the fluid dynamics of the device. These changes in flow need to be monitored because strong diastolic rotational flow, no areas of blood stasis, low blood residence time, and wall shear rates above 500 s, can help prevent thrombus deposition. Particle image velocimetry was used to observe the planar flow patterns and wall shear rates of the 12 cc Penn State Pneumatic Pediatric VAD (PVAD) at a normal operating condition and a reduced beat rate. At the reduced beat rate, the PVAD showed an earlier loss of rotational pattern, increased blood residence time, and an overall reduction in wall shear rate at the outer walls. Because this reduction in flow rate could lead to a possible increase in thrombus deposition, it may be necessary to look into other options for weaning a patient from the PVAD.