International Microsurgery Club Webinar Series-Bridging the Knowledge Gap during the COVID-19 Pandemic.

BACKGROUND: The impact of the coronavirus disease 2019 (COVID-19) outbreak shut down most conferences. To minimalize the influence, virtual meetings sprang up subsequently. International Microsurgery Club (IMC), as one of the largest professionals-only online microsurgery education groups worldwide, began to host regular weekend webinars during the pandemic to fill the knowledge gap. This study aims to discuss how webinars have fundamentally changed the way knowledge is delivered and exchanged. METHODS: From February 29, 2020 to March 14, 2021, 103 IMC webinars were reviewed and analyzed in detail to determine the use, benefit, and effect. A comparison between webinars hosted by the different societies was made as well. A questionnaire survey focusing on attendees' behavior, attitude, and using habit about webinars was also made. RESULTS: As for the 103 IMC webinar events, the peak participants were 112.3 people in average. The members requesting to join IMC abruptly increased during the pandemic, and the group activity increased dramatically. From the questionnaire (n = 68), the satisfaction level was high (8.88 ± 1.18/10). The respondents were most satisfied with the good quality of the speakers (73.5%). Not only hosts our webinar series but IMC also serves as the platform that welcomes webinars from other societies to share their information. In September 2020, International Microsurgery Webinar League was established via the significant webinar hosts, with more than 300 recorded webinar talks connected successfully. CONCLUSION: As the knowledge revolution driven by COVID-19 will continue, IMC will keep playing an essential role in exploring new and emerging opportunities to improve knowledge dissemination worldwide beyond the space-time boundary.

Chimeric profunda artery perforator - gracilis flap: A computed tomographic angiography study and case report.

BACKGROUND: The possibility of harvesting the profunda artery perforator (PAP) flap in a chimeric configuration together with the innervated gracilis muscle may be a good option for dynamic reconstruction following total glossectomies. In this paper, we present a retrospective radiological study, which evaluates the presence and characteristics of the anatomical variation of the chimeric PAP - gracilis flap. METHODS: The study sample comprised 66 patients (132 legs), 38 men, and 28 women with an average age of 56 ± 2 years old, who underwent head and neck reconstruction with a free flap. Preoperative computed tomographic angiography (CTA) was used for morphologic analysis. We present a case report of a patient with a total glossectomy reconstructed with this flap. RESULTS: A perforator in the PAP area joining with the main pedicle of the gracilis muscle was found in 38 legs (28.8%). Mean length of the pedicle from the profunda femoral artery to the point where the perforator in the PAP area and the pedicle of the gracilis joined was 3.0 ± 0.3 cm. Differences in the existence of this vascular configuration were not significant comparing groups by sex, BMI, height, side or source vessel. Motion of the new tongue was documented clinically and with electromyography. The patient achieved an intelligible speech and normal diet. CONCLUSIONS: Preoperative evaluation is necessary to assess the existence of a perforator in the PAP area joining with the main pedicle of the gracilis muscle. This chimeric flap has been demonstrated useful for dynamic reconstruction of a patient with a total glossectomy.

A Novel Technique to Secure the Skull Post in a Thin Skull Allowing for Surgical Navigation in Infants.

Several surgical procedures have been described to correct the deformities associated with craniosynostosis. To simplify the prediction of results, virtual planning techniques and image-guided surgery have been used. Digital planning can be transferred to the operating room using osteotomy and cutting guides or surgical navigation. We describe a novel bone fixation method that allows for anchoring of a cranial dynamic reference frame (DRF) in a steady manner. DRF can be used for registration and as a reference for surgical navigation in an infant's skull. We describe this novel technique to overcome the problems of DRF fixation on an infant's thin and weak calvarium. We fixed the DRF to the cranium using this new system. A 6-hole X-shaped miniplate was placed using 5 screws, leaving 1 of the central holes free. The self-drilling screw that anchors the DRF in position was placed in the free central hole, avoiding calvarial bone breakage and allowing for surgical navigation. To the best of our knowledge, the present study is the first report of this DRF anchorage modification for surgical navigation during surgery of craniosynostosis in an infant.

The thin profunda femoral artery perforator flap for tongue reconstruction.

BACKGROUND: With the ongoing global epidemic of obesity in the Western countries, thigh flaps such as the profunda artery perforator (PAP) free flap, have been less favorable for glossectomy reconstruction due to large bulk of adipose tissue associated with traditional subfascial harvest. In this article, we present a series of 10 patients who underwent reconstruction with suprafascial PAP free flaps following oncologic tongue resection. METHODS: Our series included six men and four women with an average age of 53.9 years old (range, 28-71 years). All patients underwent preoperative computed tomographic angiography (CTA) for selection of the most suitable perforator and preoperative design of its customized thickness. Flap elevation was performed at the superficial fascia layer while modifying the plane of dissection according to the specific bulk needs in each case. RESULTS: Flaps survived in nine patients; one flap failed due to vasospasm. Mean pedicle length was 7.4 cm (range, 6-8 cm). Skin paddle dimensions varied between 8 × 6 and 15 × 9 cm. Flaps thicknesses ranged from 0.4 to 3 cm. Functional outcome was evaluated at 6 months follow up: good speech and deglutition functional outcomes relative to extent of resection were observed. CONCLUSIONS: The dissection above the superficial fascia layer represents an important refinement to the traditional fasciocutaneous PAP flap. Flap thickness can be tailored to avoid excess of bulk in the medial thigh observed in larger BMI populations.

International Microsurgery Club and World Society for Reconstructive Microsurgery Webinar: Career Building in Microsurgery.

Career building can be challenging for young surgeons, especially when topics such as lifestyle, work-life balance and subspecialization arise. Suggestions and advice from senior colleagues is very valuable but many young surgeons do not have such opportunities or are limited to a few senior surgeons. The International Microsurgery Club (IMC), in collaboration with the World Society of Reconstructive Microsurgery, organized a combined webinar for this topic and invited world renowned microsurgery masters polled by the IMC members to join, including Prof. Peter Neligan (Emeritus from University of Washington, United States), Prof. Raja Sabapathy (Ganga Hospital, India), Dr. Gregory Buncke (The Buncke Clinic, United States), Prof. Isao Koshima (Hiroshima University Hospital, Japan), Prof. David Chwei-Chin Chuang (Chang Gung Memorial Hospital, Taiwan), and Prof. Eric Santamaria (Hospital General Dr. Manuel Gea Gonzalez, Mexico) on May 1, 2022. Prof. Joon-Pio Hong (Asan Medical Center, South Korea) and Prof. Fu-Chan Wei (Chang Gung Memorial Hospital, Taiwan) were also selected but unfortunately could not make it and were therefore invited to another event in April 2023, summarized in a recently published paper. There is ample literature reporting on different aspects of developing a microsurgical career but the goal of this session was to offer an opportunity for direct exchange with experienced mentors. Moreover, insights from experienced microsurgeons from different part of the world were more likely to offer different perspectives on aspects such as career building, failure management, and team culture. This webinar event was moderated by Dr. Jung-Ju Huang (Taiwan), Dr. Susana Heredero (Spain), and Dr. Wei F. Chen (United States).

Fibula free flap in maxillomandibular reconstruction. Factors related to osteosynthesis plates' complications.

The aim of this paper is to identify risk factors associated with the development of osteosynthesis plates' related complications in fibula free flap reconstructions. This is a case series study of consecutive fibula free flaps. Clinical and radiological variables were recorded. Patient outcomes were evaluated with special attention to osteosynthesis plates' related complications; these included plate exposure, plate fracture, loosening of screws, non-union, bone resorption, oro-cutaneous fistulas, and bone exposure. We have done a descriptive analysis, univariate analysis, and multivariate logistic regression model to explore possible risk factors for osteosynthesis plates' related complications. Data analysis was performed using R software (version 3.5.0). 111 fibula free flaps were studied. 29 patients (26.1%) developed osteosynthesis plates' related complications. The mean time to osteosynthesis plates' related complications was 22 months; range (1-120); the median and mode were 12 months. Patients with preoperative radiotherapy (34% vs 14%, p = 0.021), and secondary reconstruction (31% vs 15%, p = 0.053) had a higher incidence of osteosynthesis plates' related complications. In the univariate analysis, "preoperative radiotherapy" (OR 3.07, 95%CI = 1.139-8.242, p = 0.025) and "extraoral soft-tissue defect" (OR 2.907, 95%CI = 1.032-8.088, p = 0.042) were risk factors for osteosynthesis plates' related complications. We have observed an interaction effect: patients with mandibular Brown's classes III + IV and "secondary reconstruction" have a higher risk for osteosynthesis plates' related complications; more than 47.30 times compared to Brown's class I and "primary reconstruction" (p = 0.026). Different factors may contribute to the development of osteosynthesis plates' related complications. Our study adds important information about these. Patients with higher risk of developing complications should be informed that a second intervention to remove the plates might be necessary.

Degrees of tolerance in post-traumatic orbital volume correction: the role of prefabricated mesh.

PURPOSE: To identify factors influencing the volumetric correction of orbital fractures, and evaluate the use of prefabricated titanium mesh in their repair. MATERIALS AND METHODS: We included patients with unilateral orbital fractures and floor or medial-wall defects, subsequently reconstructed with titanium mesh, and subject to adequate follow-up with multislice, digitalized computed tomography (CT) images. Medical records were reviewed, and demographics, operative details, and postoperative course were recorded as prognostic variables. Moreover, orbital volume, apex-to-globe distance, and orbital rim area were measured using postoperative CT. Univariate analysis and a multiple-regression model were used to identify associated factors. RESULTS: A total of 32 patients fulfilled the inclusion criteria. Postoperative clinical evaluation and CT images were obtained in a mean +/- SD of 12.3 +/- 7.2 months after surgery. Clinically, 20 patients were considered normal (63%), and 12 manifested some ocular dystopia (37%). On postoperative CT, the mesh was in good position in 44% of cases, and in an insufficient position in 56% of cases. There was a significant difference between fractured and normal orbits in relation to orbital volume and apex-globe distance. Clinical evaluation significantly correlated with CT mesh placement, but there was no correlation between clinical evaluation and any of the variables measured on CT. The most important factors influencing postoperative orbital volume correction were type of fracture, affected walls, and use of prefabricated mesh. CONCLUSION: Volumetric and lineal symmetry between fractured and normal orbits are very difficult to achieve. In this study, postoperative CT measurements did not correlate with subjective clinical assessment. The clinical-radiological disagreement may be explained by measurement accuracy problems, clinical bias, or normal differences between orbits. The most important identified modifiable factor was the use of prefabricated mesh.

GABAergic and non-GABAergic thalamic, hypothalamic and basal forebrain projections to the ventral oral pontine reticular nucleus: their implication in REM sleep modulation.

The ventral part of the oral pontine reticular nucleus (vRPO) is a demonstrated site of brainstem REM-sleep generation and maintenance. The vRPO has reciprocal connections with structures that control other states of the sleep-wakefulness cycle, many situated in the basal forebrain and the diencephalon. Some of these connections utilize the inhibitory neurotransmitter GABA. The aim of the present work is to map the local origin of the basal forebrain and diencephalon projections to the vRPO whether GABAergic or non-GABAergic. A double-labelling technique combining vRPO injections of the neuronal tracer, cholera-toxin (CTB), with GAD-immunohistochemistry, was used for this purpose in adult cats. All of the numerous CTB-positive neurons in the reticular thalamic and dorsocaudal hypothalamic nuclei were double-labelled (CTB/GAD-positive) neurons. Approximately 15%, 14% and 16% of the CTB-positive neurons in the zona incerta and the dorsal and lateral hypothalamic areas are, respectively, CTB/GAD-positive neurons. However, only some double-labelled neurons were found in other hypothalamic nuclei with abundant CTB-positive neurons, such as the paraventricular nucleus, perifornical area and H1 Forel field. In addition, CTB-positive neurons were abundant in the central amygdaline nucleus, terminal stria bed nuclei, median preoptic nucleus, medial and lateral preoptic areas, dorsomedial and ventromedial hypothalamic nuclei, posterior hypothalamic area and periventricular thalamic nucleus. The GABAergic and non-GABAergic connections described here may be the morphological pillar through which these prosencephalic structures modulate, either by inhibiting or by exciting, the vRPO REM-sleep inducing neurons during the different sleep-wakefulness cycle states.

Precisión en reconstrucción orbitaria con mallas de titanio preformadas / Precision in orbital reconstruction with preformed titanium meshes

Objetivos. Evaluar la adaptación de las mallas orbitarias preformadas industrialmente en nuestro entorno. Determinar la influencia de la planificación preoperatoria y la navegación en la precisión de la reconstrucción. Material y método. Se estudió a pacientes con fracturas unilaterales de suelo orbitario reconstruidos con mallas de titanio preformadas entre 2009 y 2014. Las tomografías computarizadas (TC) se analizaron con iPlan 3.0 (BrainLab). Se importó la malla preformada en formato Standard Tesellation Language (STL) y se posicionó en la órbita sana reflejada en espejo sobre la fracturada. Se cuantificó la diferencia de volumen entre órbitas reconstruida y sana (DV), así como la adaptación del contorno de la malla a las superficies orbitarias. La navegación se hizo con el sistema Kolibrí (BrainLab). Resultados. Se incluyeron 17 reconstrucciones, 10 realizadas previa planificación y con navegación intraoperatoria. La DV fue significativamente menor en el grupo reconstruido con navegación (0,24±0,13 cc), p<0,01. En 9 pacientes la malla no se adaptaba adecuadamente en la TC preoperatoria, introduciéndose 1,88±0,27mm bajo el reborde infraorbitario y 3,23±1,3mm en la fosa nasal, con un ángulo medio de 13±5,2°. La adaptación postoperatoria fue significativamente mejor en los casos en los que se había utilizado la navegación (p<0,05). Conclusiones. Las mallas orbitarias preformadas necesitan ajustes en un 50% de nuestros casos. Planificación preoperatoria y navegación permiten identificar las órbitas en las que la adaptación no es buena y corregirla, y así mejorar la precisión de la reconstrucción (AU)

Objectives. To assess reconstruction with preformed orbital titanium meshes in our patients. To evaluate the influence of surgical planning and intraoperative navigation in orbital reconstruction accuracy. Material and method. Patients with unilateral orbital floor fractures reconstructed with preformed titanium meshes between 2009 and 2014 were included. Computed tomographies (CT) were analyzed with iPlan 3.0 (BrainLab). Orbital mesh was imported as a Standard Tesellation Language (STL) object and it was placed in the best position over the mirror uninjured orbit. Difference of volume between healthy and reconstructed orbits (VD) and variables to measure contour adaptation of the orbital mesh were evaluated. Intraoperative navigation was done with the BrainLab Kolibrí navigation system. Results. A total of 17 patients were reconstructed, 10 with preoperative planning and intraoperative navigation. VD was statistically lower in the group that was reconstructed using navigation (0.24±0.13cc), P<.01. In 9 patients the position of the mesh was not adequate in the preoperative CT: the mesh protruded 1.88±0.27mm below the infraorbital rim, and 3.23±1.3mm in the nose with an angle of 13±5.2°. Postoperative adaptation was statistically better in navigated patients (P<.05). Conclusions. Preformed orbital meshes needed adjustments in about 50% of our patients. Preoperative planning and surgical navigation help identifying them, increasing accuracy in their reconstructions (AU)

Aplicación clínica de la planificación virtual y la navegación en el tratamiento de las fracturas del suelo de la órbita / Clinical application of virtual planning and navigation for the treatment of the orbital floor fractures

El objetivo del tratamiento de las fracturas de órbita es reconstruir la forma tridimensional de las paredes orbitarias para restablecer el volumen orbitario y la función ocular. El enoftalmos y la diplopía producidos por la reconstrucción inapropiada de la anatomía orbitaria tras un traumatismo continúan siendo todavía una secuela de estas fracturas. El objetivo de este trabajo es describir la técnica de la planificación virtual y la navegación intraoperatoria en el tratamiento de fracturas de suelo y pared medial de la órbita como herramienta útil en el tratamiento de estas fracturas. La técnica de planificación virtual y navegación intraorbitaria se aplica para el tratamiento de pacientes con fracturas de suelo o pared medial de órbita. La corrección virtual de la órbita fracturada se realiza utilizando la imagen en espejo del lado sano superpuesta sobre el lado fracturado. La planificación preoperatoria permite, además, importar y seleccionar preoperatoriamnete una malla premoldeada y determinar la adecuación de esta, en forma y tamaño, para tratar la fractura. La navegación intraoperatoria permite la disección segura y adecuada del contenido orbitario («primera» navegación) y la confirmación de la adecuada reconstrucción de las paredes orbitarias («segunda» navegación). La planificación en ordenador, la cirugía virtual y la navegación intraoperatoria aportan una guía útil, precisa y segura para la reconstrucción orbitaria (AU)

The goal of the treatment of orbital fractures is to reconstruct the three-dimensional shape of the orbital walls to restore the orbital volume and eye function. Enophthalmos and diplopía caused by inappropriate orbital wall anatomy reconstruction after trauma, remain still a sequel to these fractures. The objectives of this paper are to describe the technique of virtual planning and intraoperative navigation in the treatment of floor and medial wall fractures of the orbit as a useful tool in the treatment of these fractures. We have applied the technique of virtual planning and navigation for the treatment of patients with fractures of floor and/or medial orbital wall. The virtual correction of the fractured orbit is performed using the mirror image of the healthy side superimposed on the fractured side. Preoperative computer planning also allows importing the object ‘premolded mesh' to the plan to determine its appropriateness, in shape and size, to treat the fracture. Intraoperative navigation allows a safe and proper dissection ('first' navigation) of the orbital contents and confirmed the proper reconstruction of the orbital walls ('second' navigation). Navigation allows a safe dissection of the orbital contents and a verification of the accuracy of the position of the mesh. Computer planning, virtual surgery and intraoperative navigation provide precise guidance and safety for orbital reconstruction (AU)