Alberto Meyer

Bio: Alberto Meyer is an academic researcher from University of São Paulo. The author has contributed to research in topics: Hernia & Inguinal hernia. The author has an hindex of 10, co-authored 59 publications receiving 323 citations.

Learning curve takes 65 repetitions of totally extraperitoneal laparoscopy on inguinal hernias for reduction of operating time and complications

Abstract: Inguinal hernia repair is one of the most frequently conducted surgical procedures worldwide. Totally extraperitoneal (TEP) hernioplasty has shown many advantages over traditional open surgery. However, because of increased surgical complexity, it requires more practice to achieve optimal results. The aim of this study is to evaluate the learning curve for TEP hernioplasty, analysing parameters related to the mean operating time. The secondary objective is to assess the complications and early discharge rates related to this procedure. A prospective study of 238 consecutive patients undergoing TEP hernioplasty from the same practitioner between May 2009 and May 2014, in a specialised centre for abdominal hernias in Sao Paulo, Brazil, was conducted. All data were obtained through medical records. The study included 137 patients undergoing a total of 157 TEP hernia repairs. Bilaterality and complications can influence the operating time and so were excluded. Patients with unilateral surgery and without complications were included. Patients were chronologically divided into four groups. Groups 1–3 were composed of 35 patients and group 4 of 32. There were no significant variations in clinical characteristics between the groups. The plateau of the learning curve was reached on the 65 th repetition of the surgery, with a mean operating time of 28 min (p < 0,05). Complications were only observed in the first group of 35 patients. 97% of patients were discharged early, defined as patient leaving hospital less than 12 h after surgery. After an initial reduction, the mean operating time stabilised after 65 cases. A reduction in the rate of complications was observed after 35 cases, and a rate of 97% of early discharge was achieved.

Laparoscopic totally extraperitoneal inguinal hernia repair: twenty-seven serious complications after 4565 consecutive operations.

Abstract: OBJETIVO: identificar e avaliar as complicacoes do tratamento da hernia inguinal com a colocacao de tela totalmente extraperitoneal. METODOS: Foram incluidos, em uma serie consecutiva de 4565 reparos de hernia laparoscopica, pacientes que haviam sido submetidos ao procedimento TEP entre janeiro de 2001 e janeiro de 2011. Os criterios de inclusao foram: diagnostico com hernia inguinal sintomatica, incluindo recorrencia apos correcao de hernia inguinal e cirurgia previa em abdomen inferior e pelve. Todos os pacientes > 18 anos de idade. Pacientes com hernia encarcerada na urgencia foram excluidos do estudo. RESULTADOS: Um total de 4565 hernias foram incluidas no estudo. Ocorreram 27 complicacoes graves (0,6%): 12 hemorragias (0,25%), duas lesoes da bexiga (0,04%), cinco oclusoes (0,11%), quatro perfuracoes intestinais (0,09%), uma lesao da veia iliaca (0,02%), uma lesao do nervo femoral (0,02%), duas lesoes dos vasos deferentes (0,04%) e dois obitos (0,02%) (embolia pulmonar, peritonite). CONCLUSAO: A taxa de complicacoes com o procedimento TEP e baixa. Correcao de hernia laparoscopica e uma tecnica reprodutivel e confiavel. Em nossa experiencia, existem contraindicacoes para o procedimento de TEP. A tecnica TEP deve ser minuciosa para evitar complicacoes intraoperatorias (diatermia bipolar). As complicacoes podem ocorrer mesmo apos o cirurgiao ter adquirido experiencia substancial.

Quantitative and qualitative analysis of collagen types in the fascia transversalis of inguinal hernia patients.

Abstract: BACKGROUND: Inguinal hernia is the second most common surgical case in our field. The anatomical factors alone are not enough to explain the inguinal hernia. Studies show changes in the proportion and quantity of collagen fibers in the developing of inguinal hernia. The greater production of collagen type III compared to the type I could justify the thinning of the fascia transversalis and its weakness. AIM: To determine the quantitative and qualitative changes of collagen in the fascia transversalis in inguinal hernia patients and compare them to findings from corpses without inguinal hernia. METHOD: Prospective case-control study based on the biopsy of fascia transversalis of 27 patients and 24 corpses. The technique used was hematoxylin-eosin and picrosirius colorimetry. RESULTS: The medium percent area of collagen (types I + III) and collagen type I, in both groups, show no statistic difference. The quantity of collagen type III was greater in the patients. Patients classified with Nyhus IIIa presented greater quantity of collagen type III. CONCLUSION: There is no significant difference in the quantity of collagen in the fascia transversalis of patients compared to the controls. An increase in the quantity of collagen type III was found in patients with inguinal hernia and a greater quantity in those patients classified with Nyhus IIIa.

The impact of properly diagnosed sarcopenia on postoperative outcomes after gastrointestinal surgery: A systematic review and meta-analysis.

Abstract: Background Sarcopenia is defined as the loss of muscle mass combined with loss of muscle strength, with or without loss of muscle performance. The use of this parameter as a risk factor for complications after surgery is not currently used. This meta-analysis aims to assess the impact of sarcopenia defined by radiologically and clinically criteria and its relationship with complications after gastrointestinal surgeries. Materials and methods A review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO registration number: CRD42019132221). Articles were selected from the PUBMED and EMBASE databases that adequately assessed sarcopenia and its impact on postoperative complications in gastrointestinal surgery patients. Pooled estimates of pre-operative outcome data were calculated using the odds ratio (OR) and 95% confidence interval (CI). Subgroup analysis were performed to assess each type of surgery. Results The search strategy returned 1323, with 11 studies meeting the inclusion criteria. A total of 4265 patients were analysed. The prevalence of sarcopenia between studies ranged from 6.8% to 35.9%. The meta-analysis showed an OR for complications after surgery of 3.01 (95% CI 2.55–3.55) and an OR of 2.2 (95% CI 1.44–3.36) for hospital readmission (30 days). Conclusion Sarcopenia, when properly diagnosed, is associated with an increase in late postoperative complications, as well as an increase in the number of postoperative hospital readmissions for various types of gastrointestinal surgery. We believe that any preoperative evaluation should include, in a patient at risk, tests for the diagnosis of sarcopenia and appropriate procedures to reduce its impact on the patient’s health.

The Effects of Light at Night on Circadian Clocks and Metabolism

Abstract: Most organisms display endogenously produced ∼ 24-hour fluctuations in physiology and behavior, termed circadian rhythms. Circadian rhythms are driven by a transcriptional-translational feedback loop that is hierarchically expressed throughout the brain and body, with the suprachiasmatic nucleus of the hypothalamus serving as the master circadian oscillator at the top of the hierarchy. Appropriate circadian regulation is important for many homeostatic functions including energy regulation. Multiple genes involved in nutrient metabolism display rhythmic oscillations, and metabolically related hormones such as glucagon, insulin, ghrelin, leptin, and corticosterone are released in a circadian fashion. Mice harboring mutations in circadian clock genes alter feeding behavior, endocrine signaling, and dietary fat absorption. Moreover, misalignment between behavioral and molecular circadian clocks can result in obesity in both rodents and humans. Importantly, circadian rhythms are most potently synchronized to the external environment by light information and exposure to light at night potentially disrupts circadian system function. Since the advent of electric lights around the turn of the 20th century, exposure to artificial and irregular light schedules has become commonplace. The increase in exposure to light at night parallels the global increase in the prevalence of obesity and metabolic disorders. In this review, we propose that exposure to light at night alters metabolic function through disruption of the circadian system. We first provide an introduction to the circadian system, with a specific emphasis on the effects of light on circadian rhythms. Next we address interactions between the circadian system and metabolism. Finally, we review current experimental and epidemiological work directly associating exposure to light at night and metabolism.

Innovations in Surgery Simulation: A Review of Past, Current and Future Techniques

Abstract: As a result of recent work-hours limitations and concerns for patient safety, innovations in extraclinical surgical simulation have become a desired part of residency education. Current simulation models, including cadaveric, animal, bench-top, virtual reality (VR) and robotic simulators are increasingly used in surgical training programs. Advances in telesurgery, three-dimensional (3D) printing, and the incorporation of patient-specific anatomy are paving the way for simulators to become integral components of medical training in the future. Evidence from the literature highlights the benefits of including simulations in surgical training; skills acquired through simulations translate into improvements in operating room performance. Moreover, simulations are rapidly incorporating new medical technologies and offer increasingly high-fidelity recreations of procedures. As a result, both novice and expert surgeons are able to benefit from their use. As dedicated, structured curricula are developed that incorporate simulations into daily resident training, simulated surgeries will strengthen the surgeon’s skill set, decrease hospital costs, and improve patient outcomes.

Connective tissue alteration in abdominal wall hernia

Abstract: Background: The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdominal wall hernia formation. Methods: A computer-assisted search of the medical databases PubMed and Embase was performed, together with a cross-reference search of eligible papers. Results: Fifty-two papers were included. Collagen alteration depended on the type of hernia; there were more pronounced changes in patients with a direct inguinal hernia than in those with an indirect inguinal hernia, recurrent inguinal hernia or incisional hernia. A consistent finding was a significant increase in immature type III collagen relative to the stronger type I collagen in patients with a hernia. This resulted in thinner collagen fibres with a correspondingly diminished biomechanical strength. It has been suggested that these alterations are due to variation in the synthesis, maturation or degradation of collagen by matrix metalloproteinases, in combination or alone. Conclusion: Hernia formation and recurrence is associated with altered collagen metabolism manifested by a decreased type I:III collagen ratio. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Modular tissue engineering for the vascularization of subcutaneously transplanted pancreatic islets

Abstract: The transplantation of pancreatic islets, following the Edmonton Protocol, is a promising treatment for type I diabetics. However, the need for multiple donors to achieve insulin independence reflects the large loss of islets that occurs when islets are infused into the portal vein. Finding a less hostile transplantation site that is both minimally invasive and able to support a large transplant volume is necessary to advance this approach. Although the s.c. site satisfies both these criteria, the site is poorly vascularized, precluding its utility. To address this problem, we demonstrate that modular tissue engineering results in an s.c. vascularized bed that enables the transplantation of pancreatic islets. In streptozotocin-induced diabetic SCID/beige mice, the injection of 750 rat islet equivalents embedded in endothelialized collagen modules was sufficient to restore and maintain normoglycemia for 21 days; the same number of free islets was unable to affect glucose levels. Furthermore, using CLARITY, we showed that embedded islets became revascularized and integrated with the host’s vasculature, a feature not seen in other s.c. studies. Collagen-embedded islets drove a small (albeit not significant) shift toward a proangiogenic CD206 + MHCII − (M2-like) macrophage response, which was a feature of module-associated vascularization. While these results open the potential for using s.c. islet delivery as a treatment option for type I diabetes, the more immediate benefit may be for the exploration of revascularized islet biology.

Pelvic organ prolapse and collagen-associated disorders

Abstract: Introduction and hypothesis Pelvic organ prolapse (POP) and other disorders, such as varicose veins and joint hypermobility, have been associated with changes in collagen strength and metabolism. We hypothesized that these various disorders were more prevalent in both POP patients and their family members.