Characteristics of the learning curve in robotic thoracic surgery in an emerging country.

It is not established which factors impact the learning curve (LC) in robotic thoracic surgery (RTS), especially in emerging countries. The aim of this study is to analyze LC in RTS in Brazil and identify factors that can accelerate LC. We selected the first cases of two Brazilian surgeons who started their LC. We used CUSUM and the Lowess technique to measure LC for each surgeon and Poisson regression to assess factors associated with shorter console time (CT). 58 patients were operated by each surgeon and included in the analysis. Surgeries performed were different: Surgeon I (SI) performed 54 lobectomies (93.11%), whereas Surgeon II (SII) had a varied mix of cases. SI was proctored in his first 10 cases (17.24%), while SII in his first 41 cases (70.68%). The mean interval between surgeries was 8 days for SI and 16 days for SII. There were differences in the LC phases of the two surgeons, mainly regarding complications and conversions. There was shorter CT by 30% in the presence of a proctor, and by 20% with the Da Vinci Xi. Mix of cases did not seem to contribute to faster LC. Higher frequency between surgeries seems to be associated with a faster curve. Presence of proctor and use of bolder technologies reduced console time. We wonder if in phase 3 it is necessary to keep a proctor on complex cases to avoid serious complications. More studies are necessary to understand which factors impact the LC.

Endocrine-Metabolic Response in Patients Undergoing Multiple Body Contouring Surgeries After Massive Weight Loss.

BACKGROUND: The endocrine-metabolic response to trauma is directly related to its magnitude, but little is known about the adverse effects of combined surgical procedures on morbidity. OBJECTIVES: The authors sought to evaluate risk factors by measuring the endocrine-metabolic response in patients who underwent multiple body-contouring surgeries after massive weight loss. METHODS: This prospective, randomized, interventional study included 46 massive weight loss patients who experienced a weight loss >30% of their body mass index (BMI) and were referred for body contouring surgery. Patients were randomly allocated to the control group (n = 10) or intervention group (n = 36), which in turn was divided into 3 subgroups (n = 12, each) according to BMI, surgical time, and scar length values. Blood samples were collected from all patients at different time points to assess biological stress markers. RESULTS: Levels of IL-6 in patients in the higher ranges of BMI and operating time and with more extensive scar length were significantly higher in the immediate postoperative period compared with baseline. Concentrations of noradrenaline were significantly higher 24 hours after surgery compared with baseline only in patients in the higher range of operating time. A higher level of IL-6 at 72 hours after surgery compared with baseline was associated with more extensive scar length. Levels of other biological stress markers did not significantly differ. CONCLUSIONS: The combination of surgical procedures did not significantly affect the concentrations of most biological stress markers. The variable of operating time most influenced increase in plasma concentrations of stress markers.

Magnetic transcutaneous fixation: an experimental study in pigs.

BACKGROUND: Magnetic subdermal implants have never been studied in the context of magnetic fixation of an external device to the body's surface. Excessive attractive force between the implant and the external device may compromise local circulation due to mechanical compression, leading to necrosis. OBJECTIVE: To evaluate the feasibility of transcutaneous magnetic fixation and assess secondary skin changes when subjected to a continuous static magnetic field. METHODS: Using the pig as an animal model, 72 implants were introduced in 12 animals. After wound healing, ultrasonography was performed to measure implant depths. Computer simulations were applied to allow magnetic attachment between implants and external devices without impairing local blood flow. External devices of different magnetic strengths were applied over the skin for 7 days. Local skin was examined and collected for analysis. A senior dermatopathologist blindly examined skin specimens and controls for abnormal findings, measuring dermal and epidermal thickness. Statistical analysis (P <0.05) was performed over the data. RESULTS: Nineteen implants presented extrusion. The remaining 53 skin sites underwent magnetic compression, of which 43 (81%) evolved uneventfully. Implant depth varied between 4.6 mm and 8.3 mm (5.8 mm; ± 8.6 mm) with estimated pressure levels between 13.28 mmHg and 37.04 mmHg (27.6 mmHg; ±6.0 mmHg). Stronger magnets were associated with an increase in dermal thickness (P = 0.011) and neovascularization (P = 0.045). CONCLUSIONS: Transcutaneous magnetic fixation is compatible with skin viability in vivo, under experimental conditions. Skin interposition between two permanent magnets resulted in a continuous static magnetic field stimulation, which showed similar effects to pulsed electromagnetic fields reported on scientific literature.

Effects of local pressure on cutaneous blood flow in pigs.

OBJECTIVE: to evaluate the effects of increasing pressures on the cutaneous blood flow in the skin of pigs. METHODS: we conducted an experimental study in pigs submitted to subcutaneous magnetic implants (n=30). After healing, were applied external magnets with varying magnetic forces to the skin, generating compression. We evaluated the cutaneous circulation of the skin under compression by the Laser Speckle Contrast Imaging (LSCI) technique. We measured the depth of the implants by ultrasonography, and applied computational simulations to the calculation of the different pressure values, considering the different distances between implants and external magnets. RESULTS: nineteen implants presented complications. The remaining 11 were submitted to different magnetic compression forces and perfusion analysis. Two linear regression models showed an inverse correlation between exerted pressure and cutaneous perfusion, with significant variation, mainly in the initial pressure increases, of up to 20mmHg. CONCLUSION: The main reduction in cutaneous blood flow resulted from initial increases of up to 20 mmHg. The results suggest that tissue ischemia can occur even in low-pressure regimes, which could contribute to the appearance of skin lesions, particularly ulcers related to medical devices.

Effects of local pressure on cutaneous blood flow in pigs / Efeitos da pressão local no fluxo sanguíneo cutâneo de porcos

ABSTRACT Objective: to evaluate the effects of increasing pressures on the cutaneous blood flow in the skin of pigs. Methods: we conducted an experimental study in pigs submitted to subcutaneous magnetic implants (n=30). After healing, were applied external magnets with varying magnetic forces to the skin, generating compression. We evaluated the cutaneous circulation of the skin under compression by the Laser Speckle Contrast Imaging (LSCI) technique. We measured the depth of the implants by ultrasonography, and applied computational simulations to the calculation of the different pressure values, considering the different distances between implants and external magnets. Results: nineteen implants presented complications. The remaining 11 were submitted to different magnetic compression forces and perfusion analysis. Two linear regression models showed an inverse correlation between exerted pressure and cutaneous perfusion, with significant variation, mainly in the initial pressure increases, of up to 20mmHg. Conclusion: The main reduction in cutaneous blood flow resulted from initial increases of up to 20 mmHg. The results suggest that tissue ischemia can occur even in low-pressure regimes, which could contribute to the appearance of skin lesions, particularly ulcers related to medical devices.

RESUMO Objetivo: avaliar os efeitos de pressões crescentes exercidas sobre a pele de porcos no fluxo sanguíneo cutâneo. Métodos: estudo experimental em porcos submetidos a implantes magnéticos subcutâneos (n=30). Após a cicatrização, foram aplicados sobre a pele, ímãs externos com forças magnéticas variadas, gerando compressão. A circulação cutânea da pele submetida à compressão foi avaliada pela técnica Laser Speckle Contrast Imaging (LSCI). A profundidade dos implantes foi medida por ultrassonografia, e simulações computacionais foram aplicadas para o cálculo dos diferentes valores de pressão, considerando-se as variadas distâncias entre implantes e ímãs externos. Resultados: dezenove implantes apresentaram complicações. Os 11 restantes foram submetidos à diferentes compressões magnéticas e análise de perfusão. Dois modelos de regressão linear mostraram uma correlação inversa entre pressão exercida e perfusão cutânea com variação significativa principalmente nos acréscimos iniciais de pressão até 20mmHg. Conclusão: a principal redução do fluxo sanguíneo cutâneo resulta dos acréscimos iniciais de pressão de até 20mmHg. Os resultados sugerem que a isquemia tecidual pode ocorrer mesmo em regimes de baixa pressão, o que poderia contribuir para surgimento de lesões de pele, particularmente as úlceras relacionadas a dispositivos médicos.

Influence of acid treatment on surface properties and in vivo performance of Ti6Al4V alloy for biomedical applications.

The purpose of this work was to investigate the influence of acid treatment on the surface properties and in vivo performance of titanium grade 5 (Ti6Al4V) alloy. Mini-implants with surface treatment were inserted into New Zealand rabbit tibia for 1, 4 and 8 weeks. SEM analysis showed intercommunicated micropores in acid treated samples. AFM showed micron and sub-micron roughness. The thickness of the titanium oxide layer increased with surface treatment, with a significant reduction of Al and V concentration. Acid treated implant removal torque was larger than without treatment. The implants/bone interface of acid treated implants showed dense adhered Ca/P particles with spreading osteoblasts after 4 weeks and newly formed bone trabeculae after 8 weeks. Analysis of rabbit blood that received treated implant showed lower Al and V contents at all times. Acid treatment improved surface morphology and mechanical stability, which allowed initial events of osseointegration, while Al-V ion release was reduced. GRAPHICAL ABTSRACT.

Functional and Volumetric Analysis of the Pectoralis Major Muscle After Submuscular Breast Augmentation.

BACKGROUND: Dual plane breast augmentation is a technical variation of the submuscular plane described as a technique that reduces contour deformities due to contraction of the pectoralis major muscle and lower risk of double-bubble deformity associated with breast ptosis. Despite improvement in the aesthetic aspect, there is still no consensus whether this technique affects the function of the pectoralis major muscle. OBJECTIVES: The aim of this study was to correlate functional with volumetric changes associated with dissection of the muscle origin in submuscular breast augmentation. METHODS: Thirty women who desired to undergo breast augmentation were selected prospectively and randomly allocated to 2 groups: 10 patients in the control group and 20 patients in the interventional group, who underwent submuscular breast augmentation. Magnetic resonance imaging and volumetric software were used to assess muscle volume and isokinetic dynamometry was used to assess function of the pectoralis major muscle. Preoperative measurements were compared with those at 3, 6, and 12 months after surgery. RESULTS: Magnetic resonance imaging revealed significant decrease in muscle volume at 6 and 12 months follow-up. The isokinetic test conducted during adduction showed a significant difference in muscle strength between groups from baseline to the 12-month follow-up, and between the 3- and 12-month follow-up. No significant differences in muscle strength during abduction were observed from baseline to the 3-, 6-, and 12-month follow-up. CONCLUSIONS: Submuscular breast augmentation reduced muscle strength during adduction 12 months after surgery, but without a significant correlation with volumetric muscle loss.

Viability of randomized skin flaps-an experimental study in rats.

BACKGROUND: Randomized skin flaps are extensively used in plastic surgery, but the possibility of necrosis has challenged their use. Several studies have been conducted aiming to find ways to reduce the occurrence of necrosis. We evaluated the effects of pentoxifylline (PTX) and hyaluronidase (HLD), each alone or combined, on randomized rat skin flaps. MATERIALS AND METHODS: Fifty male Wistar rats were divided into five groups of 10 animals each: control I, control II, PTX, HLD, PTX-HLD. Substances were administered from the first to the 14th postoperative day. The necrotic area was measured on the seventh and 14th postoperative day; the animals were killed on the 14th day, when samples were collected for histologic and immunohistochemical examination. RESULTS: On the seventh day, percentage of the necrotic area was significantly reduced in PTX, HLD, and PTX-HLD animals compared with control groups. On 14th day, percentage of the necrotic area in PTX, HDL, and PTX-HLD groups was also significantly reduced compared with control groups. PTX and PTX-HLD showed a significant reduction in dermis cellularity, VV of macrophages, and myofibroblasts compared with control groups; PTX showed a significant enhancement of LV of blood vessels compared with all other groups. CONCLUSIONS: The use of each substance alone or combined increased flap viability compared with control groups. On the seventh day, PTX exhibited lower viability than HLD, whereas on the 14th day there was no difference between treated groups. PTX alone enhanced the LV of blood vessels, whereas PTX-HLD did not. However, PTX-HLD was more effective in decreasing the dermis cellularity and macrophage VV than HLD alone.

Use of platelet-rich plasma in deep second- and third-degree burns.

Unfortunately burns are a common occurrence, leading to scarring or death. Platelet-rich plasma (PRP) contains many growth factors that can accelerate wound healing. We analyzed the use of PRP in deep second-degree (dSD), deep second-degree associated with diabetes mellitus (dSDD), and third-degree (TD) burns in rats. Sixty syngeneic rats divided into three groups (dSD, dSDD, and TD) were burned, half receiving topical PRP and half being used as control; 10 additional rats per group were used for PRP preparation. On day 21, the animals were sacrificed and skin biopsies were collected. dSD and dSDD wounds treated with PRP showed faster wound closure, reduction in CD31-, CD68-, CD163-, MPO-, and in TGF-ß-positive cells, and an increase in MMP2-positive cells. The neo-epidermis was thinner in the control of both the dSD and dSDD groups and granulation tissue was less reduced in the control of both the dSDD and TD groups. These results indicate that PRP can accelerate the healing process in dSD and dSDD, but not in TD burns.

Volumetric Evaluation of the Mammary Gland and Pectoralis Major Muscle following Subglandular and Submuscular Breast Augmentation.

BACKGROUND: Besides being a procedure with high level of patient satisfaction, one of the main causes for reoperation after breast augmentation is related to contour deformities and changes in breast volume. Few objective data are available on postoperative volumetric analysis following breast augmentation. The aim of this study was to evaluate volume changes in the breast parenchyma and pectoralis major muscle after breast augmentation with the placement of silicone implants in the subglandular and submuscular planes. METHODS: Fifty-eight women were randomly allocated either to the subglandular group (n = 24) or submuscular group (n = 24) and underwent breast augmentation in the subglandular or submuscular plane, respectively, or to a control group (n = 10) and received no intervention. Volumetric magnetic resonance imaging was performed at inclusion in all participants and either after 6 and 12 months in the control group or at 6 and 12 months after surgery in the intervention groups. RESULTS: Twelve months after breast augmentation, only the subglandular group had a significant reduction in glandular volume (mean, 22.8 percent), while patients in the submuscular group were the only ones showing significant reduction in muscle volume (mean, 49.80 percent). CONCLUSIONS: Atrophy of the breast parenchyma occurred after subglandular breast augmentation, but not following submuscular breast augmentation. In contrast, submuscular breast augmentation caused atrophy of the pectoralis major muscle. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Evaluation of the effects of silicone implants on the breast parenchyma.

BACKGROUND: Despite being the cosmetic procedure most performed worldwide, there are still few objective measurements of postoperative volumetric analysis of breast augmentation available in the literature. OBJECTIVE: The aim of this study was to evaluate volumetric changes in the breast parenchyma after the placement of silicone implants in the subglandular plane. METHODS: Thirty-four women were randomly allocated to the intervention group (n = 24), who underwent breast augmentation in the subglandular plane, or to the control group (n = 10), who received no intervention. Volumetric magnetic resonance imaging was performed at inclusion, and after 6 and 12 months in all participants. The non-parametric Friedman's test was used for statistical analysis. RESULTS: There was a significant reduction in glandular volume (mean, 22%) at 12 months postoperatively in patients who underwent breast augmentation. CONCLUSIONS: Breast augmentation caused reduction in the volume of the breast parenchyma. LEVEL OF EVIDENCE: 3 Therapeutic.

Utility of video-assisted endoscopy in transaxillary breast augmentation.

BACKGROUND: Breast augmentation through incisions in the axillae is an option for patients who wish to avoid scars on the breasts. The axillary approach also preserves the mammary parenchyma and lactiferous ducts. The utility of video-assisted endoscopy during this procedure as a means to improve safety and aesthetic outcomes remains debatable. OBJECTIVES: The authors compared outcomes of transaxillary breast augmentation with and without video-assisted endoscopy. METHODS: Thirty-four women who underwent transaxillary breast augmentation with or without video-assisted endoscopy were evaluated in a prospective, randomized study. Patients received high-profile silicone implants in the subglandular plane and were monitored for an average of 25 months. Operating time, complication rates, postoperative pain, patient satisfaction, and aesthetic parameters were evaluated. RESULTS: Operative time were significantly longer for patients who underwent transaxillary breast augmentation with video-assisted endoscopy compared with patients who underwent nonendoscopic surgery. CONCLUSIONS: Video-assisted endoscopy increased operating time but did not improve the safety of transaxillary breast augmentation or yield better aesthetic outcomes. LEVEL OF EVIDENCE: 3 Therapeutic.

Volumetric and functional evaluation of the gluteus maximus muscle after augmentation gluteoplasty using silicone implants.

BACKGROUND: The gluteal muscles have been very important throughout the evolution of mankind for the adoption of the bipedal posture. Over the past 15 years, the intramuscular technique has become popular and has been improved, with enhanced results and reduced levels of postoperative complications. The insertion of gluteal implants within the musculature may be an intrinsic compression factor of these muscles. The objective of the present study was to evaluate the gluteus maximus function and its variation over a 12-month period after the insertion of the implant. METHODS: This was a prospective, controlled, clinical study. All subjects were female patients, with anthropometric characteristics and body mass index within preset limits to establish similar groups. Isokinetic test gluteus computed tomographic scans and clinical nutritional assessment were conducted in four stages during the study period: preoperatively and 3, 6, and 12 months after surgery. RESULTS: The study group presented 6.14 percent muscle atrophy to the left and 6.43 percent muscle atrophy to the right after the procedure. Muscle strength presented differences in hip flexion and adduction tests. CONCLUSIONS: The gluteus maximus muscle presents atrophy secondarily to gluteal augmentation surgery with implants. Variations in gluteus maximus muscle strength should not be attributed primarily to the surgical procedure or to the implants; physiologic and multifactorial variations should also be considered. Strength and volume variations did not show a significant correlation. Gluteal augmentation with implants was effective in improving the waist-to-hip ratio and in changing the anthropometric pattern from android to gynoid. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

A new model for the standardization of experimental burn wounds.

BACKGROUND: Burns are common and recurrent events treated by physicians on a daily basis at most emergency rooms around the world. There is a constant need to understand the physiopathology of burns, so as to minimize their devastating results. The objective of the present report is to describe a burn apparatus in association with an innovative method of animal fixation, as to produce burns of varying sizes and depths. METHODS: Rats were subjected to burns of 60 °C, 70 °C, and 80 °C for 10 s and after 3 days half of the rats in each group were killed and the resulting lesions were analyzed using histological techniques. In the other half of the rats the wound was measured weakly until complete re-epithelialization. RESULTS: All burns were easily visible and the histological feature for the 60 °C burn was a superficial second-degree burn (28% of the dermis), for 70 °C we observed a deep second-degree burn (72% of the dermis), and in the 80 °C group, a third degree-burn was present (100% of the dermis). CONCLUSIONS: This is a safe, reliable, easy to construct and use model that has the ability to produce a regular and uniform reproducible burn due to precise temperature control associated with standardized animal positioning.

Effects of TachoSil and 5-fluorouracil on colonic anastomotic healing.

BACKGROUND: The administration of intraperitoneal (IP) 5-fluorouracil (5-FU) during the early postoperative period after cytoreductive surgery can decrease local cancer recurrence but may also cause impairment of the anastomotic healing. This study examined the effects of the use of this therapy and of the anastomotic sealing with TachoSil, a fibrin-thrombin coated sealant (FTCS), on the healing of colon anastomoses. MATERIALS AND METHODS: Forty male rats were divided into four groups (1-4, 10 rats each) that underwent transection and anastomosis of the left colon. The anastomoses were covered with FTCS in groups 2 and 4. Saline solution (2 mL/d-groups 1 and 2) or 5-FU (20 mg/kg/d; groups 3 and 4) was administered IP once daily for 3 d. Bursting pressure (BP) was recorded, and the anastomoses were examined macroscopically and graded histologically. RESULTS: The relative weight loss was significantly higher in group 3 than in the other groups (P = 0.0004). Anastomotic dehiscence, postoperative adhesion formation, perianastomotic collections, and preanastomotic dilatation did not differ significantly among groups. BP was significantly lower in group 3 compared with all other groups (P = 0.001). Neoangiogenesis was significantly lower in group 3 compared with groups 1 and 2 (P = 0.05). Fibroblastic activity was significantly higher in group 1 compared with group 3 (P = 0.035). Inflammatory cell infiltration and collagen deposition did not differ significantly among groups. CONCLUSIONS: Our results shown that the early postoperative IP chemotherapy with 5-FU impaired the healing of colon anastomoses. However, anastomotic sealing with FTCS reversed some of the negative effects of this therapy.

Intramuscular technique for gluteal augmentation: determination and quantification of muscle atrophy and implant position by computed tomographic scan.

BACKGROUND: New surgical techniques for gluteal augmentation have improved final results. It is estimated that more than 35,000 patients have undergone augmentation gluteoplasty using implants. The authors sought to determine and quantify the presence of muscle atrophy, and to evaluate implant positioning using the intramuscular technique. METHODS: Twenty-three female patients were selected prospectively for this study and underwent intramuscular gluteal augmentation using gluteal implants of a round or oval base. Computed tomographic scanning and three-dimensional volumetric reconstruction were used to investigate muscle atrophy and implant position, with comparison of the results between the preoperative scan and scans obtained 3, 6, and 12 months after surgery. RESULTS: Three-dimensional reconstruction and volumetric analysis showed muscular atrophy. After 12 months of follow-up, 34 gluteal muscles (17 patients) were analyzed, with 4.3 percent atrophy remaining on the right side and 2.6 percent on the left side. Twenty-three patients were studied regarding position (46 gluteal implants). All oval base implants introduced in a vertical direction (seven patients) turned to an oblique direction, following the direction of muscle fibers by 3 months after surgery. Two patients showed rotation of the implant. CONCLUSIONS: The presence of a gluteal implant caused muscle atrophy. However, it did not lead to clinical or physical limitations. It is not important whether the implants are positioned vertically or obliquely, provided that they are symmetric. The technique proved to be safe in maintaining the intramuscular position of the implant, with good satisfaction for the patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Reducing wound complications in gluteal augmentation surgery.

BACKGROUND: Over the past 30 years, many techniques have been proposed for gluteal augmentation with implants. The intramuscular technique provided greatly improved results and a consequent increase in the number of such procedures performed in Brazil. However, the data available in the medical literature reveal high rates of wound complications, mostly seroma and dehiscence. The aim of this study was to present changes in the management of the wound of augmentation gluteoplasty with silicone implants in an attempt to reduce the rates of postoperative complications. METHODS: Twenty female candidates for augmentation gluteoplasty were selected prospectively and submitted to the procedure with a modified technique. The incidence of wound complications was compared with the data of the authors and of the literature. RESULTS: In the comparison between homogeneous groups of patients, the modified technique reduced the rate of wound complications from 35 percent to 5 percent. The most frequent complications were seroma and dehiscence. The combination of liposuction of the flanks was not a risk factor for the occurrence of these complications. CONCLUSIONS: Reduction of the undermined subcutaneous area, application of adhesion stitches, and maintenance of good vascularization in the sacral region are the keystones of the authors' proposal. The modifications of the technique presented here are simple and easy to perform, and have proved effective in reducing complications during augmentation gluteoplasty with silicone implants. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.