Viable Tissue Research Articles

Initial Outcomes After Unicompartmental Tibiofemoral Bipolar Osteochondral and Meniscal Allograft Transplantation in the Knee Using MOPS-Preserved Fresh (Viable) Tissues

Background: Unicompartmental tibiofemoral bipolar osteochondral allograft transplantation (OCAT) with meniscal allograft transplantation (MAT) has not historically been associated with consistently successful outcomes for treatment of knee articular cartilage defects with meniscal deficiency. Hypothesis: Primary OCAT and MAT using fresh tissues will be associated with successful short-term outcomes based on statistically significant and clinically meaningful improvements in pain and function in the majority of patients. Study Design: Case series; Level of evidence, 4. Methods: Patients were prospectively enrolled into a registry for outcomes after OCAT and MAT. Patients included those who underwent primary OCAT and MAT using Missouri Osteochondral Preservation System (MOPS)–preserved allografts for treatment of large bipolar tibiofemoral articular cartilage defects with meniscal deficiency and had a minimum of 2-year follow-up data. Results: A total of 76 patients (n = 52 male; 68%) met inclusion criteria (mean follow-up, 52 months). The mean age was 41.1 years (range, 15-69 years), and the mean body mass index was 28.9 (range, 17-46); 48 patients underwent another OCAT in addition to the unicompartmental bipolar tibiofemoral OCAT and MAT; 23 patients (30.3%) were documented to be nonadherent to the prescribed postoperative restriction and rehabilitation protocol. The initial success rate (>2 years) was 77.6%, with 8 patients (10.5%) undergoing revision and 9 (11.8%) converting to arthroplasty. Variables associated with an increased risk for treatment failure (revision or arthroplasty) included ipsilateral osteotomy (P = .046; odds ratio [OR] = 3.3), ipsilateral concurrent procedure (P = .0057; OR = 5.5), and nonadherence (P = .0009; OR = 7.2). None of the patients undergoing revision surgery required arthroplasty at the time of data analysis such that the overall success rate for primary and revision unicompartmental bipolar OCA plus MAT was 88.2%. There were statistically significant (P < .0001) and clinically important improvements for all patient-reported outcomes at each annual follow-up time point. Conclusion: Unicompartmental tibiofemoral bipolar OCAT and MAT can result in successful short-term outcomes (2-6 years) and satisfaction in the majority of patients (78%). Primary MOPS-preserved OCAT with MAT for treatment of femoral condyle and tibial plateau articular cartilage defects with concurrent meniscal deficiency was associated with statistically significant and clinically meaningful improvements in patient-reported measures of pain and function.

Assessing the arrhythmogenic risk of engineered heart tissue patches through in silico application on infarcted ventricle models

BackgroundPost myocardial infarction (MI) ventricles contain fibrotic tissue and may have disrupted electrical properties, both of which predispose to an increased risk of life-threatening arrhythmias. Application of epicardial patches obtained from human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a potential long-term therapy to treat heart failure resulting from post MI remodelling. However, whether the introduction of these patches is anti- or pro-arrhythmic has not been studied. MethodsWe studied arrhythmic risk using in silico engineered heart tissue (EHT) patch engraftment on human post-MI ventricular models. Two patient models were studied, including one with a large dense scar and one with an apparent channel of preserved viability bordered on both sides by scar. In each heart model a virtual EHT patch was introduced as a layer of viable tissue overlying the scarred area, with hiPSC-CMs electrophysiological properties. The incidence of re-entrant and sustained activation in simulations with and without EHT patches was assessed and the arrhythmia inducibility compared in the context of different EHT patch properties (conduction velocity (CV) and action potential duration (APD)). The impact of the EHT patch on the likelihood of focal ectopic impulse propagation was estimated by assessing the minimum stimulus strength and duration required to generate a propagating impulse in the scar border zone (BZ) with and without patch. ResultsWe uncovered two main mechanisms by which ventricular tachycardia (VT) risk could be either augmented or attenuated by the interaction of the patch with the tissue. In the case of isthmus-related VT, our simulations predict that EHT patches can prevent the induction of VT when the, generally longer, hiPSC-CMs APD is reduced towards more physiological values. In the case of large dense scar, we found that, an EHT patch with CV similar to the host myocardium does not promote VT, while EHT patches with lower CV increase the risk of VT, by promoting both non-sustained and sustained re-entry. Finally, our simulations indicate that electrically coupled EHT patches reduce the likelihood of propagation of focal ectopic impulses. ConclusionsThe introduction of EHT patches as a treatment for heart failure has the potential to augment or attenuate the risk of ventricular arrhythmias, and variations in the anatomic configuration of the substrate, the functional properties of the BZ and the electrophysiologic properties of the patch itself will determine the overall impact. Planning for delivery of this therapy will need to consider the possible impact on arrhythmia.

Osteo-core plasty: minimally invasive approach for subchondral pathologies

The subchondral bone is a critical part of the osteochondral unit, providing nutrients to the overlying articular cartilage, thereby maintaining viability of the chondral tissue. The subchondral bone also provides firm mechanical support to assist with stability of the articular cartilage and distribution of stress. Subchondral bone pathology, diagnosed as a bone marrow lesion (BML) on magnetic resonance imaging, may be seen in a variety of pathologic conditions, including knee osteoarthritis (OA). Bone marrow lesions accelerate degenerative changes in the knee joint, and treatment of these lesions may prolong joint longevity. Presently, treatment options for subchondral bone lesions are limited. Osteo-core plasty is a minimally invasive treatment for subchondral bone pathology that consists of two parts: (1) decompression of bone marrow and the administration of bone marrow aspirate concentrate (BMAC) to promote tissue healing, and (2) implantation of bone autograft to provide mechanical support. In an observational study 24 patients with bone marrow lesions have been treated with Osteo-core plasty due to symptomatic bone marrow lesions. At 2 year follow-up they showed a significant improvement in patient-reported scores compared to the preoperative assessment. Based on early clinical data Osteo-core plasty has demonstrated clinical efficacy in treatment of symptomatic bone marrow lesions associated with knee osteoarthritis.

Development of an in vitro mouse cultured uterine tissue model for the endometrial regenerative therapy

The endometrium is a characteristic structure that undergoes sequential phases involving regeneration and shedding of the functional area. It is believed that the stroma and stem cells found in the endothelium's basal layer are what cause regeneration. This process is impacted by numerous endometrial diseases which decrease the fertility. The absence of readily available animal‒level models is the fundamental constraint on the research into the regenerative treatment. This paper presented an air‒liquid culture model, established to investigate the suitable conditions for maintaining the survival of mouse uterine tissue in vitro. The submerged culture model was used as a control. The culture lasted for 16 days. The evaluations of the structure (H &amp; E staining), viability (live/dead staining), and function (embryo implantation) of the uterine tissue were performed to confirm the efficacy of the model. The obtained results showed that the mouse uterine tissues cultured in an air‒liquid condition recovered their tissue structure clearly, remained stable throughout the survey up until day 12, and displayed impaired degradation on the 16th day. On the other hand, by the 12th day, the submerged culture model had clearly degraded. Additionally, compared to the submerged culture model, the viability of tissue cultured under air‒liquid conditions demonstrated the superiority with the P-value of 0.05. Only the tissues, cultured in an air‒liquid environment, showed the embryos attaching to the endometrium's surface. In summary, the air‒liquid culture conditions supported the maintenance of a stable tissue structure for 12 days. This model could be suitable for the study of therapies for mouse‒damaged endometrial tissue in vitro with a duration of up to three estrous cycles.

An unusual case of chronic osteomyelitis in a 4-year-old male child: A case report

Abstract Chronic osteomyelitis is a complex and devastating surgical disease with a variety of etiologies and a multimodal approach towards its treatment. The aim of treatment is eradication of infection and restoration of function of the limb with surgical management being the cornerstone of treatment. Despite the need of surgical debridement in the treatment of chronic osteomyelitis, the reliable radiological and tissue diagnosis along with appropriate antimicrobial therapy is paramount for the success of treatment. Biofilm forms the most notorious reason for persistence of infection in a bone and needs thorough debridement till only viable tissue is left behind. Control of chronic osteomyelitis is challenging for the surgeons even today and demands patience from both the surgeon and the patient. Here, we are going to report an unusual case of osteomyelitis in a 4 year of male child.

A benchtop brain injury model using resected donor tissue from patients with Chiari malformation.

The use of live animal models for testing new therapies for brain and spinal cord repair is a controversial area. Live animal models have associated ethical issues and scientific concerns regarding the predictability of human responses. Alternative models that replicate the 3D architecture of the central nervous system have prompted the development of organotypic neural injury models. However, the lack of reliable means to access normal human neural tissue has driven reliance on pathological or post-mortem tissue which limits their biological utility. We have established a protocol to use donor cerebellar tonsillar tissue surgically resected from patients with Chiari malformation (cerebellar herniation towards the foramen magnum, with ectopic rather than diseased tissue) to develop an in vitro organotypic model of traumatic brain injury. Viable tissue was maintained for approximately 2 weeks with all the major neural cell types detected. Traumatic injuries could be introduced into the slices with some cardinal features of post-injury pathology evident. Biomaterial placement was also feasible within the in vitro lesions. Accordingly, this 'proof-of-concept' study demonstrates that the model offers potential as an alternative to the use of animal tissue for preclinical testing in neural tissue engineering. To our knowledge, this is the first demonstration that donor tissue from patients with Chiari malformation can be used to develop a benchtop model of traumatic brain injury. However, significant challenges in relation to the clinical availability of tissue were encountered, and we discuss logistical issues that must be considered for model scale-up.

A comparative study of human and porcine-derived decellularised nerve matrices.

Decellularised extracellular matrix (dECM) biomaterials originating from allogeneic and xenogeneic tissues have been broadly studied in the field of regenerative medicine and have already been used in clinical treatments. Allogeneic dECMs are considered more compatible, but they have the drawback of extremely limited human tissue sources. Their availability is also restricted by the health and age of the donors. To investigate the viability of xenogeneic tissues as a substitute for human tissues, we fabricated both porcine decellularised nerve matrix (pDNM) and human decellularised nerve matrix for a comprehensive comparison. Photomicrographs showed that both dECM scaffolds retained the ECM microstructures of native human nerve tissues. Proteomic analysis demonstrated that the protein compositions of both dECMs were also very similar to each other. Their functional ECM contents effectively promoted the proliferation, migration, and maturation of primary human Schwann cells in vitro. However, pDNM contained a few antigens that induced severe host immune responses in humanised mice. Interestingly, after removing the α-galactosidase antigen, the immune responses were highly alleviated and the pre-treated pDNM maintained a human decellularised nerve matrix-like pro-regenerative phenotype. Therefore, we believe that an α-galactosidase-free pDNM may serve as a viable substitute for human decellularised nerve matrix in future clinical applications.

Experiments and simulations demonstrating the rapid ultrasonic rewarming of frozen tissue cryovials

The development of methods to safely rewarm large cryopreserved biological samples remains a barrier to the widespread adoption of cryopreservation. Here, experiments and simulations were performed to demonstrate that ultrasound can increase rewarming rates relative to thermal conduction alone. An ultrasonic rewarming setup based on a custom 444 kHz tubular piezoelectric transducer was designed, characterized, and tested with 2 ml cryovials filled with frozen ground beef. Rewarming rates were characterized in the -20 °C to 5 °C range. Thermal conduction-based rewarming was compared to thermal conduction plus ultrasonic rewarming, demonstrating a tenfold increase in rewarming rate when ultrasound was applied. The maximum recorded rewarming rate with ultrasound was 57° C/min, approximately 2.5 times faster than with thermal conduction alone. Coupled acoustic and thermal simulations were developed and showed good agreement with the heating rates demonstrated experimentally and were also used to demonstrate spatial heating distributions with small (<3° C) temperature differentials throughout the sample when the sample was below 0° C. The experiments and simulations demonstrate the potential for ultrasonic cryovial rewarming with a possible application to large volume rewarming, as faster rewarming rates may improve the viability of cryopreserved tissues and reduce the time needed for cells to regain normal function.

Abstract C028: The differential burden of BRCA2 gene mutation in prevalent cancers in Nigeria: Any difference between Africa and the world?

Abstract Introduction: The high mortality rate among cancer patients in Africa has been attributed to the high rate of late-stage presentation, aggressiveness, and metastatic nature of the tumors. The manifestation of cancer has also been linked with mutation of DNA repair genes including BRCA1, evidenced by the lack of expression of the tumor suppressors in the affected tissue. However, in Africa, there is a paucity of studies on the frequency of BRCA2 gene mutation in prevalent cancers. This study determined the prevalence of BRCA2 mutation in common cancers in Nigeria in a bid to compare the disparity of the mutation between Africa and elsewhere. Methods: This retrospective study included 51, 54, 58, 48, and 55 viable formalin-fixed Paraffin-embedded tissues of the breast, colorectal, endometrial, ovarian, and prostate cancers, respectively diagnosed between 2017 and 2019 in two tertiary health care facilities in Southern Nigeria. Tissues were stained for BRCA2 protein using the immunohistochemical technique, scored based on staining intensity, and documented as 0, +1, +2, and +3. Tissues with scores of 0 and +1 were considered negative whereas those with scores of +2 and +3 were considered positive. Descriptive, Chi-square test and Pearson’s correlation were carried out and significance was set at ≤0.05. Results: The mean age of women diagnosed with endometrial cancer was lower (41.34 ± 9.16 years) compared with breast, colorectal, ovarian, and prostate cancers (51.00 ± 10.98 years, 47.34 ± 14.73 years, 50.15 ± 12.29 years, and 72.66 ± 8.67 years, respectively). The prevalence of BRCA2 mutation was higher in endometrial cancer (78.4%) than in breast, colorectal, ovarian, and prostate cancers (41.5%, 25%, 54.2%, and 65.1%, respectively) at p&amp;lt; 0.001. There was a direct relationship between age and BRCA2 mutation among women with endometrial cancer (p= 0.005). Conclusion: This study suggests that the prevalence of BRCA2 mutation is high in Southern Nigeria and could be linked with the poor survival rate observed among cancer patients in West Africa. Citation Format: Jude Ogechukwu Okoye, Chiemeka Michael Emeka, Okechi Obioma. The differential burden of BRCA2 gene mutation in prevalent cancers in Nigeria: Any difference between Africa and the world? [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C028.

Advances in In Vitro and In Vivo Bioreactor-Based Bone Generation for Craniofacial Tissue Engineering.

Craniofacial reconstruction requires robust bone of specified geometry for the repair to be both functional and aesthetic. While native bone from elsewhere in the body can be harvested, shaped, and implanted within a defect, using either an in vitro or in vivo bioreactors eliminates donor site morbidity while increasing the customizability of the generated tissue. In vitro bioreactors utilize cells harvested from the patient, a scaffold, and a device to increase mass transfer of nutrients, oxygen, and waste, allowing for generation of larger viable tissues. In vivo bioreactors utilize the patient's own body as a source of cells and of nutrient transfer and involve the implantation of a scaffold with or without growth factors adjacent to vasculature, followed by the eventual transfer of vascularized, mineralized tissue to the defect site. Several different models of in vitro bioreactors exist, and several different implantation sites have been successfully utilized for in vivo tissue generation and defect repair in humans. In this review, we discuss the specifics of each bioreactor strategy, as well as the advantages and disadvantages of each and the future directions for the engineering of bony tissues for craniofacial defect repair.

Biomaterial-based 3D bioprinting strategy for orthopedic tissue engineering.

The advent of three-dimensional (3D) bioprinting has enabled impressive progress in the development of 3D cellular constructs to mimic the structural and functional characteristics of natural tissues. Bioprinting has considerable translational potential in tissue engineering and regenerative medicine. This review highlights the rational design and biofabrication strategies of diverse 3D bioprinted tissue constructs for orthopedic tissue engineering applications. First, we elucidate the fundamentals of 3D bioprinting techniques and biomaterial inks and discuss the basic design principles of bioprinted tissue constructs. Next, we describe the rationale and key considerations in 3D bioprinting of tissues in many different aspects. Thereafter, we outline the recent advances in 3D bioprinting technology for orthopedic tissue engineering applications, along with detailed strategies of the engineering methods and materials used, and discuss the possibilities and limitations of different 3D bioprinted tissue products. Finally, we summarize the current challenges and future directions of 3D bioprinting technology in orthopedic tissue engineering and regenerative medicine. This review not only delineates the representative 3D bioprinting strategies and their tissue engineering applications, but also provides new insights for the clinical translation of 3D bioprinted tissues to aid in prompting the future development of orthopedic implants. STATEMENT OF SIGNIFICANCE: 3D bioprinting has driven major innovations in the field of tissue engineering and regenerative medicine; aiming to develop a functional viable tissue construct that provides an alternative regenerative therapy for musculoskeletal tissue regeneration. 3D bioprinting-based biofabrication strategies could open new clinical possibilities for creating equivalent tissue substitutes with the ability to customize them to meet patient demands. In this review, we summarize the significance and recent advances in 3D bioprinting technology and advanced bioinks. We highlight the rationale for biofabrication strategies using 3D bioprinting for orthopedic tissue engineering applications. Furthermore, we offer ample perspective and new insights into the current challenges and future direction of orthopedic bioprinting translation research.

Case Study: Reimplementation of the Proximal Third of the Arm

Introduction: Microsurgical reimplantation in patients faces challenges due to complex factors, concerning the comorbidities of the patient and the type and severity of the amputation. The one-year survival rate is 90, 9% [1]. Plastic surgeons and a multidisciplinary team will be needed to perform microsurgical techniques, such as the use of tridimensional models to reconstruct different body parts using top-notch technology [2]. This study aims to evaluate the technique of reimplantation of the third proximal left arm in a patient with a traumatic amputation. Background of the Case Study: 49-years old man suffered an amputation of his left forearm by an industrial grinding machine in his workplace on October 5th, 2017, which resulted in a total avulsion of his limb. The patient was taken to the Emergency room to perform a warm ischemic technique for around 30 minutes. Physicians kept the amputated forearm on ice for 3 hours and conducted the intraoperative ischemia for 4 hours. The surgery included an extent debridement of the devitalized muscles, injured tendons and vessels, and the osteosynthesis of the radius and ulna without complications. After one year, researchers conducted the metacarpophalangeal capsuloplasty, tenolysis of the extensors and opening of the first space and section of the pronator quadratus. Conclusion: Revascularization within the first four hours was crucial because it prevented permanent damage to the tissues. The surgery technique focused on the reconstruction of the viable tissues, resulted in the reimplantation of the forearm.

Functional performance of children with Myelomeningocele submitted to intrauterine repair and conventional surgery

Introduction: Myelomeningocele (MMC) is an embryonic malformation that occurs in the first four weeks of gestation due to a failure in the closure of the neural tube. They have multifactorial etiology such as genetic and environmental factors that affect folic acid metabolism. Several anomalies may be associated with MMC, with the occurrence of hydrocephalus and Arnold Chiari type II malformation being most present. Surgical repair should ideally occur within the first 24 hours after birth to prevent or decrease the risk of infection, preservation of all viable nerve tissue, anatomical reconstitution. However, surgical repair of MMC intrauterine has shown substantial benefit in all babies submitted to this intervention. Objective: To compare the functional performance of children with MMC who underwent intrauterine surgical repair and those who did traditional surgery at birth. Methods: Cross-sectional study carried out at the UCB School-Clinic, where children treated with MMC were evaluated, analyzing their motor status and functional performance using the Pediatric Evaluation of Disability Inventory (PEDI) for a quantitative record of functional capacity and autonomy in daily activities, in the areas of self-care, mobility and social function. Results: There was a statistically significant relevance on the mobility function (p=0.01) for children who underwent intrauterine repair when compared to children who underwent traditional surgery. Conclusion: There is a strong relationship of better functionality of children who underwent intrauterine surgery when compared to children who underwent traditional surgery.

ВЫБОР МЕТОДА РЕКОНСТРУКЦИИ ПОЗИТРОННО-ЭМИССИОННЫХ ЭКГ-СИНХРОНИЗОВАННЫХ ИССЛЕДОВАНИЙ И ЕГО ВЛИЯНИЕ НА РАССЧИТАННЫЕ ОБЪЁМНЫЕ ПОКАЗАТЕЛИ ФУНКЦИИ МИОКАРДА ЛЕВОГО ЖЕЛУДОЧКА И ВИЗУАЛЬНОЕ КАЧЕСТВО ИЗОБРАЖЕНИЙ

Ischemic heart disease is one of the leading causes of mortality in the Russian Federation. Timely diagnosis of this condition allows you to determine the optimal treatment tactics. Positron emission tomography with 18-fluorodeoxyglucose is a method for verifying viable cardiac tissue in patients with myocardial infarction. The methods used for the reconstruction of positron emission tomograms can affect the quantitative indicators of the contractile function of the myocardium. Materials and methods. The study retrospectively included 12 patients who underwent PET/CT with 18-fluorodeoxyglucose, the results of which were reconstructed using filtered back projection methods and iterative reconstruction, with ECG synchronization and division of ECG R-R intervals into 8, 10 and 16 frames. The obtained images were evaluated visually by two radiologists, and the quantitative parameters characterizing the contractile function of the left ventricular myocardium were compared in pairs. Results. There were no significant differences in the assessment of quantitative indicators such as end-systolic and diastolic volumes, stroke volume and ejection fraction. However, the iterative reconstruction results show less data scatter than the filtered back projection reconstruction method. In visual analysis, the best quality of reconstructions by iterative methods is noted. Conclusions. Thus, the recommended method for both visual analysis and quantification is iterative reconstruction, regardless of the number of timing windows used. A spread in the number of used reconstructed fragments of the cardiac cycle in the range of 8-16, commonly used in clinical practice, can be recommended.

Drug sensitivity profiling of 3D tumor tissue cultures in the pediatric precision oncology program INFORM

The international precision oncology program INFORM enrolls relapsed/refractory pediatric cancer patients for comprehensive molecular analysis. We report a two-year pilot study implementing ex vivo drug sensitivity profiling (DSP) using a library of 75–78 clinically relevant drugs. We included 132 viable tumor samples from 35 pediatric oncology centers in seven countries. DSP was conducted on multicellular fresh tumor tissue spheroid cultures in 384-well plates with an overall mean processing time of three weeks. In 89 cases (67%), sufficient viable tissue was received; 69 (78%) passed internal quality controls. The DSP results matched the identified molecular targets, including BRAF, ALK, MET, and TP53 status. Drug vulnerabilities were identified in 80% of cases lacking actionable (very) high-evidence molecular events, adding value to the molecular data. Striking parallels between clinical courses and the DSP results were observed in selected patients. Overall, DSP in clinical real-time is feasible in international multicenter precision oncology programs.

Towards an Established Intraoperative Oncological Favorable Tool: Results of Fluorescein-Guided Resection from a Monocentric, Prospective Series of 93 Primary Glioblastoma Patients.

It is commonly reported that maximizing surgical resection of contrast-enhancing regions in patients with glioblastoma improves overall survival. Efforts to achieve an improved rate of resection have included several tools: among those, the recent widespread of fluorophores. Sodium fluorescein is an unspecific, vascular dye which tends to accumulate in areas with an altered blood-brain barrier. In this retrospective analysis of patients prospectively enrolled in the FLUOCERTUM study, we aimed to assess the role of fluorescein-guided surgery on surgical radicality, survival, and morbidity. A retrospective review based on 93 consecutively and prospectively enrolled IDH wild-type glioblastoma patients (2016-2022) was performed; fluorescence characteristics, rate of resection, clinical outcome, and survival were analyzed. No side effect related to fluorescein occurred; all of the tumors presented a strong yellow-green enhancement and fluorescein was judged fundamental in distinguishing tumors from viable tissue in all cases. Gross total resection was achieved in 77 cases out of 93 patients (82.8%). After a mean follow-up time of 17.4 months (3-78 months), the median progression-free survival was 12 months, with a PFS-6 and PFS-12 of 94.2% and 50%, respectively, whereas median overall survival was estimated to be 16 months; survival at 6, 12, and 24 months was 91.8%, 72.3%, and 30.1%, respectively. Based on these results, we can assert that the fluorescein-guided technique is a safe and valuable method for patients harboring a newly diagnosed, untreated glioblastoma.

110 ANEURYSMECTOMY AND SURGICAL ABLATION: WHEN?

Abstract A 60-year-old man with a previous myocardial infarction was admitted to our ICU for acute pulmonary edema in the context of an acute antero-lateral non-ST elevation myocardial infarction. Echocardiography showed severe left ventricular (LV) dilatation with extensive wall motion abnormalities, large apical aneurysm and severe systolic dysfunction. Coronary angiography showed a triple-vessel disease with proximal occlusion of the left anterior descending artery. During the hospitalization, multiple episodes of drug-resistant monomorphic ventricular tachycardias occurred, requiring repeated DC Shock. After Heart Team discussion, the patient underwent coronary artery bypass grafting, LV restoration according to the procedure described by Guilmet and surgical cryoablation. The Guilmet septoexclusion is indicated when the interventricular septum is more involved than the free wall. After aneurysm incision, cryolesions were applied at the septum and at the transitional zone of the scar and viable tissue. Thus, the anterior free wall was sewn obliquely to the septum. Finally, the edges of the incision, anterior and septal, were sewn together to assure a definitive hemostasis (overcoat technique). After surgery, an implantable cardioverter-defibrillator was implanted in secondary prevention. The postoperative course and subsequent cardiological follow-up were characterized by a gradual clinical improvement with mild increasing in LV function and reduction in ventricular arrhythmias. Nowadays, combined aneurysmectomy and endocardial ablation are rarely performed, but should be considered in patients with LV aneurysm who manifest drug-resistant ventricular arrhythmias. Encircling cryoablation in a remodelled ventricle is safe and effective in reducing ventricular arrhythmias which are a negative prognostic factor.

Is Nitropaste Effective in Stressed Flaps?

Topical nitroglycerine (nitropaste) is an agent that has seen popularization in plastic surgery in recent years. A low-cost medication functioning, by inducing vasodilation primarily in the venous system and inhibiting platelet aggregation, has shown the ability to provide benefits in clinically concerning skin flaps. In random-pattern skin flaps, research shows that topical nitroglycerine decreases flap loss and increases the percentage of viable tissue. In mastectomy skin flaps, there have been multiple studies showing significant decreases in flap necrosis and need for debridement in patients undergoing topical nitroglycerine application without changes in complications profiles. These studies have included patients undergoing and not undergoing implant-based breast reconstruction. There are no data examining myocutaneous or perforator flaps. In free flaps, there is research showing benefit of nitroglycerine in breaking vasospasm and inducing vasodilation in microsurgery. Overall, topical nitroglycerine is a proven entity effective at increasing viable tissue in random-pattern skin flaps and shows clear benefits in the reduction of mastectomy skin flap necrosis with minimal adverse effects or additional cost. Further research is needed into other areas of plastic surgery where it may be of value.

Chitosan-Based Membranes for Skin Wound Repair in a Dorsal Fold Chamber Rat Model.

Frequently, deep partial and full-thickness skin wounds do not spontaneously regenerate. To restore the normal function of skin, epidermal and dermal components have to be supplied to the wound bed by grafting various substrates. Available options are limited and frequently costly. Herein, authors present a possible approach using 3D skin scaffolds capable of mimicking structure and biological functions of the extracellular matrix, providing, in parallel, a good environment for cell attachment, proliferation and differentiation. Low-molecular weight chitosan-based membranes were prepared by freeze-drying and ionizing radiation techniques to be used as skin scaffolds. Poly (vinyl alcohol), PVA, vinyl pyrrolidone, VP, and gelatin from cold water fish were incorporated. Information regarding membranes' physical-chemical properties from SEM analysis, swelling and weight loss, together with biological response through in vitro assays (using Human Caucasian Fetal Foreskin Fibroblast) allowed the selection of an optimized batch of membranes that was used as skin scaffold in a dorsal rat model wound. The in vivo implantation assays (in Wistar rats) resulted in very promising results: (i) healing process faster than control; (ii) good vascularization; (iii) viable new tissues morphologically functional.

Surgical Approach to Rhino-Orbital Mucormycosis using Contrast Enhanced MRI as Roadmap

Introduction Increase in Mucormycosis cases following COVID-19 infection was major concern due to angio-invasive nature causing necrosis. Aggressive surgical resection is necessary to combat this infection. Identifying areas of involvement like orbit, infratemporal fossa and nature of involvement (enhancing or non-enhancing) is best assessed by MRI. Hence, we decided to use MRI as surgical roadmap for disease clearance. Materials and Methods All post-COVID suspected mucormycosis cases based on clinical suspicion underwent MRI and nasal endoscopic biopsy. In MRI we evaluated T1 with contrast and T2 with fat suppression. Once Mucormycosis was confirmed by biopsy, Amphotericin B was started with monitoring of biochemical parameters. Surgical resection till level of viable tissue was reached was done based on MRI findings. Post-operatively patients underwent nasal douching and endoscopic surveillance. Results Our surgical experience shows that maximum patients had to undergo unilateral FESS with modified endoscopic Denker’s approach and opening of pterygopalatine and infratemporal fossa. We conclude that all patients must minimally undergo the above surgery. Endoscopic Denker’s approach allows easy post-operative surveillance. The pterygopalatine and infratemporal fossa is anatomically hidden by posterior wall of maxilla. Since we found more than 50% involvement of these areas, the necessity to open and visualise the areas in our opinion is must in all cases of post-COVID rhino-orbital mucormycosis. Conclusion Post-COVID Rhino-Orbital Mucormycosis requires high index of suspicion. Underrated symptoms like headache, facial pain and facial swelling in post-COVID patients with associated immunocompromised state like diabetes mellitus must be thoroughly investigated by MRI nose, paranasal sinus and orbit. Surgical debridement as dictated by MRI and routine inspection of pterygopalatine and infratemporal fossa should be done.