BACKGROUND: In the event of an advanced rectal carcinoma, an evisceration with rectal amputation may become necessary. The resulting defects, due to their extent, depth, or local tissue damage from previous surgeries and radiation, can in many cases only be closed through free microvascular tissue transfer. In this case series, we demonstrate the successful combination of a musculocutaneous musculus vastus lateralis flap (MVL) with a direct connection to the superior gluteal artery. MATERIALS AND METHODS: Over a 47-month period, we retrospectively examined 11 cases of patients with dorsal pelvic defects after evisceration and rectal amputation that could not be closed using local or regional means. In cases of extensive defects with deep pararectal wound cavities, all these patients underwent defect coverage through a free myocutaneous MVL flap with a direct vascular anastomosis to the superior gluteal vessels. RESULTS: The mean defect size was 290.0 cm² (SD: 131.2; range: 200-600 cm²). The mean defect depth was 10.5 cm, necessitating MVL flap reconstruction with an average size of 336.3 cm². Three operative revisions were required due to postoperative bleeding. There were no arterial or venous thromboses, and no flap loss occurred. Only one necrosis of a distal flap tip was observed, which could be corrected secondarily by direct suturing. The case-mix evaluation yielded an average value of 24.251 (SD: 21.699; range: 7.036-65.748) points, emphasizing the complexity of the cases. CONCLUSIONS: Our results indicate that a free microvascular MVL flap is a viable therapeutic option for pararectal defects that cannot be closed by local or regional methods. The superior gluteal artery proves to be a safe and sufficient vascular connection. In combination, even extensive defects can be successfully closed.
PURPOSE: Beside many advantages, disadvantages such as reduced degrees of freedom and poorer depth perception are still apparent in laparoscopic surgery. 3D visualization and the development of complex instruments are intended to counteract the disadvantages. We want to find out whether the use of complex instruments and 3D visualization has an influence on the performance of novices. METHODS: 48 medical students with no experience in laparoscopic surgery or simulator-based laparoscopy training were included. They were randomized in four groups according to a stratification assessment. During a structured training period they completed the FLS-Tasks "PEG Transfer", "Pattern Cut" and "Intracorporeal Suture" and a transfer task based on these three. Two groups used conventional laparoscopic instruments with 3D or 2D visualization, two groups used complex curved instruments. The groups were compared in terms of their performance. RESULTS: In 2D laparoscopy there was a better performance with straight instruments vs. curved instruments in PEG Transfer and Intracorporeal Suture. In the transfer task, fewer errors were made with straight instruments. In 2D vs. 3D laparoscopy when using complex curved instruments there was an advantage in Intracorporeal Suture and PEG Transfer for 3D visualization. Regarding the transfer exercise, a better performance was observed and fewer errors were made in 3D group. CONCLUSION: We could show that learning laparoscopic techniques with complex curved instruments is more difficult with standard 2D visualization and can be overcome using 3D optics. The use of curved instruments under 3D vision seems to be advantageous when working on more difficult tasks.
Laparoscopy , Simulation Training , Humans , Clinical Competence , Imaging, Three-Dimensional/methods , Laparoscopy/methods , Learning Curve , Simulation Training/methods
Having established itself in various other areas of surgery as well as in urology, robotics is increasingly gaining importance in plastic surgery. The case presented in this manuscript describes the first published robotic-assisted harvesting of a latissimus dorsi muscle free flap in the German-speaking world. The aim is to increase the knowledge of robotics in plastic surgery and to support the introduction of robotic-assisted plastic surgery in Germany.
Free Tissue Flaps , Robotic Surgical Procedures , Superficial Back Muscles , Tissue and Organ Harvesting , Humans , Superficial Back Muscles/transplantation , Tissue and Organ Harvesting/methods , Robotic Surgical Procedures/methods , Free Tissue Flaps/surgery , Male , Microsurgery/methods , Female
Introduction: This study compares five augmented reality (AR) vasculature visualization techniques in a mixed-reality laparoscopy simulator with 50 medical professionals and analyzes their impact on the surgeon. Material and methods: ââThe different visualization techniques' abilities to convey depth were measured using the participant's accuracy in an objective depth sorting task. Demographic data and subjective measures, such as the preference of each AR visualization technique and potential application areas, were collected with questionnaires. Results: Despite measuring differences in objective measurements across the visualization techniques, they were not statistically significant. In the subjective measures, however, 55% of the participants rated visualization technique II, 'Opaque with single-color Fresnel highlights', as their favorite. Participants felt that AR could be useful for various surgeries, especially complex surgeries (100%). Almost all participants agreed that AR could potentially improve surgical parameters, such as patient safety (88%), complication rate (84%), and identifying risk structures (96%). Conclusions: More studies are needed on the effect of different visualizations on task performance, as well as more sophisticated and effective visualization techniques for the operating room. With the findings of this study, we encourage the development of new study setups to advance surgical AR.
Augmented Reality , Laparoscopy , Surgeons , Surgery, Computer-Assisted , Humans , Laparoscopy/methods , Surgery, Computer-Assisted/methods
BACKGROUND: Analysis of surgical instrument motion is applicable in surgical skill assessment and monitoring of the learning progress in laparoscopy. Current commercial instrument tracking technology (optical or electromagnetic) has specific limitations and is expensive. Therefore, in this study, we apply inexpensive, off-the-shelf inertial sensors to track laparoscopic instruments in a training scenario. METHODS: We calibrated two laparoscopic instruments to the inertial sensor and investigated its accuracy on a 3D-printed phantom. In a user study during a one-week laparoscopy training course with medical students and physicians, we then documented and compared the training effect in laparoscopic tasks on a commercially available laparoscopy trainer (Laparo Analytic, Laparo Medical Simulators, Wilcza, Poland) and the newly developed tracking setup. RESULTS: Eighteen participants (twelve medical students and six physicians) participated in the study. The student subgroup showed significantly poorer results for the count of swings (CS) and count of rotations (CR) at the beginning of the training compared to the physician subgroup (p = 0.012 and p = 0.042). After training, the student subgroup showed significant improvements in the rotatory angle sum, CS, and CR (p = 0.025, p = 0.004 and p = 0.024). After training, there were no significant differences between medical students and physicians. There was a strong correlation between the measured learning success (LS) from the data of our inertial measurement unit system (LSIMU) and the Laparo Analytic (LSLap) (Pearson's r = 0.79). CONCLUSION: In the current study, we observed a good and valid performance of inertial measurement units as a possible tool for instrument tracking and surgical skill assessment. Moreover, we conclude that the sensor can meaningfully examine the learning progress of medical students in an ex-vivo setting.
Laparoscopy , Physicians , Humans , Clinical Competence , Laparoscopy/methods , Motor Skills , Learning
PURPOSE: Only a few studies have evaluated Augmented Reality (AR) in in vivo simulations compared to traditional laparoscopy; further research is especially needed regarding the most effective AR visualization technique. This pilot study aims to determine, under controlled conditions on a 3D-printed phantom, whether an AR laparoscope improves surgical outcomes over conventional laparoscopy without augmentation. METHODS: We selected six surgical residents at a similar level of training and had them perform a laparoscopic task. The participants repeated the experiment three times, using different 3D phantoms and visualizations: Floating AR, Occlusion AR, and without any AR visualization (Control). Surgical performance was determined using objective measurements. Subjective measures, such as task load and potential application areas, were collected with questionnaires. RESULTS: Differences in operative time, total touching time, and SurgTLX scores showed no statistical significance ([Formula: see text]). However, when assessing the invasiveness of the simulated intervention, the comparison revealed a statistically significant difference ([Formula: see text]). Participants felt AR could be useful for various surgeries, especially for liver, sigmoid, and pancreatic resections (100%). Almost all participants agreed that AR could potentially lead to improved surgical parameters, such as operative time (83%), complication rate (83%), and identifying risk structures (83%). CONCLUSION: According to our results, AR may have great potential in visceral surgery and based on the objective measures of the study, may improve surgeons' performance in terms of an atraumatic approach. In this pilot study, participants consistently took more time to complete the task, had more contact with the vascular tree, were significantly more invasive, and scored higher on the SurgTLX survey than with AR.
Augmented Reality , Laparoscopy , Surgery, Computer-Assisted , Humans , Surgery, Computer-Assisted/methods , Pilot Projects , Laparoscopy/methods , Phantoms, Imaging
BACKGROUND: The "digital era" in the field of medicine is the new "here and now". Artificial intelligence has entered many fields of medicine and is recently emerging in the field of organ transplantation. Solid organs remain a scarce resource. Being able to predict the outcome after liver transplantation promises to solve one of the long-standing problems within organ transplantation. What is the perfect donor recipient match? Within this work we developed and validated a novel deep-learning-based donor-recipient allocation system for liver transplantation. METHOD: In this study we used data collected from all liver transplant patients between 2004 and 2019 at the university transplantation centre in Munich. We aimed to design a transparent and interpretable deep learning framework to predict the outcome after liver transplantation. An individually designed neural network was developed to meet the unique requirements of transplantation data. The metrics used to determine the model quality and its level of performance are accuracy, cross-entropy loss, and F1 score as well as AUC score. RESULTS: A total of 529 transplantations with a total of 1058 matching donor and recipient observations were added into the database. The combined prediction of all outcome parameters was 95.8% accurate (cross-entropy loss of 0.042). The prediction of death within the hospital was 94.3% accurate (cross-entropy loss of 0.057). The overall F1 score was 0.899 on average, whereas the overall AUC score was 0.940. CONCLUSION: With the achieved results, the network serves as a reliable tool to predict survival. It adds new insight into the potential of deep learning to assist medical decisions. Especially in the field of transplantation, an AUC Score of 94% is very valuable. This neuronal network is unique as it utilizes transparent and easily interpretable data to predict the outcome after liver transplantation. Further validation must be performed prior to utilization in a clinical context.
Image registration is a commonly required task in computer assisted surgical procedures. Existing registration methods in laparoscopic navigation systems suffer from several constraints, such as lack of deformation compensation. The proposed algorithm aims to provide the surgeons with updated navigational information about the deep-seated anatomy, which considers the continuous deformations in the operating environment. We extended an initial rigid registration to a shape-preserving deformable registration pathway by incorporating user interaction and an iterative mesh editing scheme which preserves local details. The proposed deformable registration workflow was tested with phantom and animal trial datasets. A qualitative evaluation based on expert feedback demonstrated satisfactory outcome, and an commensurate execution efficiency was achieved. The improvements offered by the method, couples with its relatively easy implementation, makes it an attractive method for adoption in future pre-clinical and clinical applications of augmented reality assisted surgeries.
Augmented Reality , Laparoscopy , Surgeons , Surgery, Computer-Assisted , Algorithms , Animals , Humans
BACKGROUND: Breast reconstruction using autologous tissue is an integral part of breast cancer treatment. While many studies have elucidated the impact of breast reconstruction on patients' quality of life, self-esteem, sexuality and more, there is a lack of objective data regarding the effects on external observers. Aim of this study was to investigate the change in gaze pattern of independent observers depending on the stage of DIEP-flap breast reconstruction. MATERIALS AND METHODS: Eye-tracking technology was utilized to analyze the eye movements of 58 study participants while viewing 2 D photographs of a patient after mastectomy and different stages of DIEP-flap breast reconstruction. Time until first fixation and total time of fixation were recorded and con- secutively analyzed for the right and left breast on each image. RESULTS: Overall, the total time of fixation of the operated breast decreased significantly over the different stages of breast reconstruction, with p<0.001. At the same time, there was no statistically significant change in total time of fixation of the non-operated breast, with p=0.174. The time until first fixation showed a significant increase over the different stages of reconstruction for the reconstructed breast, with p<0.001, while no significant differences were found for the opposite breast, with p=0.344. CONCLUSION: Mastectomy and the individual steps of breast reconstruction alter the perception of breast cancer patients. Over the course of breast reconstruction, the deviation of gaze in the direction of the affected breast is reversed.
Breast Neoplasms , Mammaplasty , Perforator Flap , Breast Neoplasms/surgery , Epigastric Arteries/surgery , Eye-Tracking Technology , Female , Humans , Mammaplasty/methods , Mastectomy , Perforator Flap/surgery , Quality of Life
BACKGROUND: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Laparoscopic lower rectal resections in accordance with the oncological principles are recommended as the gold standard for CRC surgical management. However, the learning curve for adopting these techniques is quite steep and the incomplete resections are predictive of local recurrence. This study was conducted in an attempt to find a way to help surgeons to overcome some of these difficulties and define the right resection margins. MATERIAL AND METHODS: As such, we carried out two laparoscopic lower rectal resections in porcine models. The first resection was performed following the ligation and selective infusion of Indocyanine Green (ICG) into the inferior mesenteric artery (IMA), and the second after the ligation of both inferior mesenteric artery and vein (IMV) and systemic intravenous infusion of ICG. Fluorescence was detected in real time by means of an infrared imaging system. RESULTS: Sharp resection margins were defined after intra-arterial infusion, and all the tissues in the IMA basin were colored in the first case. In the second model every organ and tissue was colored except the rectum, urinary bladder and ductus deferens. CONCLUSIONS: Although systemic intra-venous application of ICG and negative-staining of the rectum including the mesorectum is much easier compared to laparoscopic inter-arterial perfusion through IMA, image results of selevtive IMA-perfusion appear in sharper discrimination of the several layers. Further investigation should focus on simplifying this technique.
Laparoscopy , Rectal Neoplasms , Animals , Feasibility Studies , Indocyanine Green , Rectal Neoplasms/surgery , Rectum/diagnostic imaging , Rectum/surgery , Staining and Labeling , Swine
OBJECTIVE: The aim of our study was to conduct a systematic review and meta-analysis comparing the survival outcomes of IBD-associated and non-IBD-associated CRC. SUMMARY OF BACKGROUND DATA: Investigations comparing the prognosis in CRC patients with and without IBD have yielded conflicting results. METHODS: PubMed/MEDLINE, Embase, Web of Science, Cochrane Library were searched for studies evaluating the prognostic outcomes between CRC patients with IBD and those without IBD. Estimates of survival-related outcomes and clinicopathological features in IBD-CRC and non-IBD CRC were pooled through random-effects or fix-effects models. The study is registered with PROSPERO, CRD42021261513. RESULTS: Of 12,768 records identified, twenty-five studies with 8034 IBD-CRC and 810,526 non-IBD CRC patients were included in the analysis. IBD-CRC patients have a significant worse overall survival (OS) with the hazard ratio (HR) of 1.33 [95% confidence interval (CI): 1.20-1.47] than those without IBD. Pooled estimates of cancer-specific survival demonstrated that IBD-CRC patients had a poorer cancer-specific survival than those without IBD with fixed-effect model (HR, 2.17; 95% CI: 1.68-2.78; P < 0.0001). Moreover, ulcerative colitis-associated CRC patients have favorable OS than Crohn's disease-associated CRC (HR 0.79,95% CI: 0.72-0.87). Compared to non-IBD-CRC, patients with IBD-associated CRC are characterized by an increased rate of poor differentiation (OR 2.02, 95% CI: 1.57-2.61), mucinous or signet ring cell carcinoma (OR 2.43, 95% CI: 1.34-4.42), synchronous tumors (OR 3.18, 95% CI: 2.26-4.47), right-sided CRC (OR 1.62, 95%CI: 1.05-2.05), male patients (OR 1.10, 95% CI: 1.05-1.16), and a reduced rate of R0 resections (OR 0.60, 95% CI: 0.44-0.82). CONCLUSIONS: IBD-CRC patients have a significant worse OS than patients with non-IBD CRC, which may be attributed to more aggressive histological characteristics and a lower rate of R0 resections at the primary tumor site. Optimized therapeutic standards and tailored follow-up strategies might improve the prognosis of IBD-CRC patients.
Colitis, Ulcerative , Colorectal Neoplasms , Crohn Disease , Inflammatory Bowel Diseases , Colorectal Neoplasms/pathology , Crohn Disease/complications , Humans , Inflammatory Bowel Diseases/complications , Male , Prognosis
The quality of mesorectal resection is crucial for resection in rectal cancer, which should be performed by laparoscopy for better outcome. The use of indocyanine green (ICG) fluorescence is now routinely used in some centers to evaluate bowel perfusion. Previous studies have demonstrated in animal models that selective intra-arterial ICG staining can be used to define and visualize resection margins in rectal cancer. In this animal study, we investigate if laparoscopic intra-arterial catheterization is feasible and the staining of resection margins when performing total mesorectal excision with a laparoscopic medial to lateral approach is possible. In 4 pigs, laparoscopic catheterization of the inferior mesenteric artery (IMA) is performed using a seldinger technique. After a bolus injection of 10 ml ICG with a concentration of 0.25 mg/ml, a continuous intra-arterial perfusion was established at a rate of 2 ml/min. The quality of the staining was evaluated qualitatively. Laparoscopic catheterization was possible in all cases, and the average time for this was 30.25 ± 3.54 min. We observed a significant fluorescent signal in all areas of the IMA supplied, but not in other parts of the abdominal cavity or organs. In addition, the mesorectum showed a sharp border between stained and unstained tissue. Intraoperative isolated fluorescence augmentation of the rectum, including the mesorectum by laparoscopic catheterization, is feasible. Inferior mesenteric artery catheterization and ICG perfusion can provide a fluorescence-guided roadmap to identify the correct plane in total mesorectal excision, which should be investigated in further studies.
Indocyanine Green/chemistry , Mesenteric Artery, Inferior/diagnostic imaging , Optical Imaging/methods , Rectum/surgery , Animals , Catheterization , Laparoscopy , Swine
We studied the long-term effect of ileal transposition (IT) metabolic surgery on the hepatokines: retinol-binding protein-4 (RBP4), α-2-HS-glycoprotein (aHSG/fetuin-A), and fibroblast growth factor 21 (FGF21), C-reactive protein (CRP) plasma levels, glucose metabolism, body weight, liver histology, as well as total lipids concentration in muscle, liver, and fat tissue of obese Zucker (Crl:ZUC(ORL)-Leprfa) rats. 14 adult males were randomly submitted either to IT or SHAM (control) surgery. Pre-operative hepatokines plasma levels were not significantly different in rats submitted to IT or SHAM protocol. Three months after the procedures the plasma levels of RBP4, aHSG, FGF21, and CRP were significantly lower in IT-operated animals when compared to SHAM-operated group. Three and 12 weeks after the IT and SHAM surgery, the AUCOGTT were significantly lower than AUCOGTT before the surgery. HOMA-IR was lower in rats after IT surgery in comparison to the SHAM-operated rats. Muscle and liver total lipids concentration was reduced after the IT procedure when compared to pre-IT conditions. IT had a significant reductive impact on the body weight in comparison to SHAM surgery in the 4th, 6th, 8th, and 10th week after the surgery. We conclude that IT reduces hepatokines' plasma concentrations, muscle and liver total lipids concentration but not the inflammatory processes in the liver of Zucker (Crl:ZUC(ORL)-Leprfa) rats.
Bariatric Surgery/methods , Cytokines/blood , Glucose/metabolism , Lipid Metabolism , Obesity/surgery , Animals , Male , Rats , Rats, Zucker
INTRODUCTION: Laparoscopic resection has become an accepted approach to liver tumour surgery. However, it is considered difficult, especially in unfavourably located lesions. AIM: To compare the outcomes of laparoscopic (LLR) and open liver resection (OLR) of posterolateral segments. MATERIAL AND METHODS: We searched the PubMed, EMBASE, and Scopus databases from inception to 30 September 2019. Full text articles and conference abstracts were included for further analysis. This review follows the PRISMA guidelines. RESULTS: From 643 articles, 15 studies (N = 1196 patients) were included in the meta-analysis. All of them were non-randomised. Our findings showed that LLR had significantly lowered overall morbidity compared to OLR (MD = 0.66; 95% CI: 0.51-0.86; p = 0.002). Length of hospital stay (MD = 2.48; 95% CI: -3.87, -1.08; p < 0.001) was also shorter in the LLR group. Operative time (MD = 55.65; 95% CI: 24.14-87.16; p < 0.001) was significantly shorter in the OLR group. In terms of blood loss, major complications, R0 resection rates, and resection margin, there were no significant differences. CONCLUSIONS: Our meta-analysis showed that the laparoscopic approach to resections of posterolateral liver segments is beneficial. However, the results are based on non-randomised trials, and further research is needed to fully establish their clinical application.
Background. Most robotic camera steering devices (RCSDs) require active steering by the surgeon and necessarily increase workload. Clinical experience shows that standard laparoscopic procedures can be performed safely as solo surgery aided by RCSDs. No evidence exists concerning exploratory or emergency procedures. We compared the performance during unexpected laparoscopic tasks on surgical simulators aided either by an RCSD controllable by head movements of the surgeon or by a human camera assistant. Methods. Forty-five medical students without previous experience with minimal invasive surgery were randomized in 2 groups, and they performed standard and unexpected laparoscopic tasks requiring complex camera movements on box trainers either using an RCSD or assisted by a human camera assistant. Efficiency and performance parameters were recorded. Results. Performance in simulated standard procedures was equivalent. In simulated exploratory procedures, we saw significantly better performance scores in the conventional group versus the RCSD group. The strongest factor for these differences was the longer camera-adjusting time in the RCSD group versus the conventional group (PEG task = 208 ± 51 seconds vs 170 ± 36 seconds, P = .005; suture task = 563 ± 126 seconds vs 454 ± 201 seconds, P = .041). Conclusion. These results, obtained on surgical simulators, indicate that the solo approach to standard surgical tasks, facilitated by an RCSD controllable by head movements, can most likely be viewed as safe. Exploratory procedures with a relevant chance for complications or procedures that require rapid, often, or complex camera movements should rather be performed with a human camera assistant.
Laparoscopy , Robotic Surgical Procedures , Robotics , Surgeons , Head Movements , Humans
The prevalence of diabetes type 2 (T2DM) and obesity is growing exponentially and becoming a global public health problem. The enzymes of glucose metabolism play a role in the pathogenesis of insulin resistance and T2DM. A pathophysiological link between different dietary patterns, HFD, obesity, T2DM and the enzymes of glucose metabolism can be used as a potential target in therapeutic strategies for the treatment of obesity, and T2DM. The aim of this study was to measure the impact of DJOS bariatric surgery and different types of dietary patterns on glycogen synthase kinase 3 α (GSK-3α), glycogen phosphorylase (PYGM, PYGL), and phosphofructokinase (PFK-1) concentrations in liver and soleus muscle tissues of rats. After 8 weeks on a high-fat diet (HF) or control diet (CD), rats underwent duodenal-jejunal omega switch (DJOS) or SHAM (control) surgery. After surgery, for the next 8 weeks, half of DJOS/SHAM animals were kept on the same diet as before, and half had a changed diet. The concentrations of GSK-3α, PYGM, PYGL and PFK-1 were measured in the soleus muscles and livers of the Sprague-Dawley rats. The type of diet applied before/after surgery had stronger impact on levels of selected metabolic enzymes than DJOS or SHAM surgery. The impact of DJOS surgery was visible for GSK-3α and PYGL concentration in the liver but not in the soleus muscle tissue. The type of bariatric surgery had an impact on liver GSK-3α concentration in all studied groups except the CD/CD group, where the impact of diet was stronger. DJOS bariatric surgery influenced the level of PYGL in the livers of rats maintained on the CD/CD diet but not from other groups. The dietary patterns applied before and after bariatric surgery, had a stronger impact on enzymes' concentrations than DJOS surgery, and the strong, deleterious effect of an HF was observed. A change of the diet per se showed a negative impact on the enzymes' tissue concentration.
