[Coverage of complex pararectal pelvic defects: role of the free myocutaneous musculus vastus lateralis flap]

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.

Laparoscopy training of novices with complex curved instruments using 2D- and 3D-visualization

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.

[Robotic-assisted harvesting of a latissimus dorsi muscle flap: a case report]

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.

AR visualizations in laparoscopy: surgeon preferences and depth assessment of vascular anatomy

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: ​​The 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.

Tracking and evaluating motion skills in laparoscopy with inertial sensors

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 (LS_IMU) and the Laparo Analytic (LS_Lap) (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.

[Change of Gaze Pattern depending on the Stage of DIEP Flap Breast Reconstruction: a Preliminary Eye-Tracking Investigation]

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.

Local Shape Preserving Deformations for Augmented Reality Assisted Laparoscopic Surgery

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.

Laparoscopic intraarterial catheterization with selective ICG fluorescence imaging in colorectal surgery

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.

Laparoscopic versus open liver resections of posterolateral liver segments - a systematic review and meta-analysis

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.

Intra-arterial versus negative-staining of embryonal resection borders with indocyanine green (ICG) fluorescence for total mesorectal excision in colorectal cancer - an experimental feasibility study in a porcine model

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.

A Robotic Camera Holder Controlled by Head Movements: Exploring This New Robot-Surgeon Interface

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.

Intraarterial indocyanine green (ICG) fluorescence augmentation by marking embryonal resection areas in colorectal surgery: a feasibility study in a porcine model

Aim: In this pilot animal study we examined whether it is possible to visualize the embryonal resection layers by using intraarterial indocyanine green (ICG) staining when performing total mesorectal excision (TME) for carcinoma of the rectum. Material and methods: We injected ICG into the inferior mesenteric artery (AMI) of four swines to see whether the watershed area of the arterial supply zone can be sufficiently visualized by fluorescence imaging in order to mark the right dissection area along the fascia parietalis before and during resection. Results: We observed a fluorescence signal in all the supplied areas of AMI but not in other parts of the abdominal cavity or other organs. Additionally, the mesorectum also showed a sharp border between colored and non-colored tissue. Conclusion: In this study we present that resection borders may be determined before resection based on ICG-perfusion and we showed that intraoperative exclusive coloring of the rectum including the mesorectum is possible. Visualizing resection borders based on ICG-perfusion before settling the first cut may be a new approach in oncological surgery.

Two unusual cases: vulvar lipoma - description of the largest case in literature. Developing myoma with the longest pedicle

The authors present two cases of benign tumors one located on the outer surface of the vulva, and the second extending beyond the vagina. The first, originating from the right pudendal lip, a lipoma measuring 23 cm in greatest diameter, weighing 6.6 kg, and the second a pedunculated, uterine smooth muscle myoma with a pedicle of 6.5 cm, maximum diameter 18 cm, weight 700 grams, which caused significant metroptosis. Operative procedures in each case were free of complications.

Reduction of the risk of rhabdomyolysis after bariatric surgery with lower fluid administration in the perioperative period: a cohort study

INTRODUCTION    Obesity is a growing worldwide problem. One of the most effective treatments is a bariatric procedure; however, surgery is associated with the risk of complications, such as staple line leakage, suture line bleeding, and rhabdomyolysis (RML). OBJECTIVES    The objective of our study was to assess the risk of RML after bariatric surgery related to intravenous fluid administration in the perioperative period. PATIENTS AND METHODS    The study involved 194 patients who underwent a bariatric surgery (laparoscopic sleeve gastrectomy or laparoscopic gastric bypass). We studied an association between the development of RML and sex, age, weight, duration of surgery, type of surgery, and the volume of intravenously administered fluids during the perioperative period. RESULTS    The median duration of surgery was 132.5 minutes. The median volume of administered fluids was 3150 ml from the introduction of anesthesia to 24 hours after surgery. Biochemical RML (creatine phosphokinase >1000 U/l) was observed in 30 patients (15.46%). RML with clinical manifestations developed in 6 patients. Multivariate logistic regression revealed an increase in the odds ratio of biochemical RML with an increase of weight on the day of surgery, operative time, and volume of intravenous fluids. A multiple regression model showed that every 500 ml of transfused fluid over the median volume increases creatine phosphokinase concentrations in the first postoperative day by 241.77 U/l over the median level, with the operative time and patient's weight remaining at median values. CONCLUSIONS    We observed an association between the administration of lower fluid volumes and a lower risk of RML. We postulate that decreasing intravenous fluid administration may reduce the risk of RML after bariatric surgery.

Grenzen des laparoskopischen Operierens bei abdomineller Sepsis

<b><i>Hintergrund: </i></b>Zahlreiche präklinische Daten weisen auf Vorteile des laparoskopischen Operierens auch bei abdomineller Sepsisquelle und septischem Patienten hin. <b><i>Methode und Ergebnisse: </i></b>Anhand derzeit verfügbarer Literatur betrachten wir die Möglichkeiten und Limitierungen laparoskopischen Operierens beim septischen Patienten mit abdominellem Fokus. Neben generellen Überlegungen werden im Speziellen das Vorgehen bei Appendizitis, Cholezystitis, perforiertem Ulkus, Sigmadivertikulitis und akuter Pankreatitis erörtert. <b><i>Schlussfolgerungen: </i></b>Erfahrene laparoskopische Chirurgen können die Sanierung der abdominellen Sepsisquelle bei Appendizitis, Cholezystitis, perforiertem Ulkus oder auch Sigmadivertikulitis sicher durchführen. Kombinationen aus interventionellen Techniken und minimal invasiven Operationen bieten insbesondere bei der perforierten Sigmadivertikulitis und bei infizierten Pankreasnekrosen innovative Ansätze, die derzeit in multizentrischen prospektiven Studien untersucht werden.

[Laparoscopic resection of the pancreatic head. Feasibility and perioperative results]

BACKGROUND

Whereas pancreatic tail resection is routinely and safely performed in several institutions, laparoscopic resection of the pancreatic head is only performed by a handful of surgeons worldwide, none of them in Germany.

PATIENTS AND METHODS

We review our experience with 9 laparoscopic pancreatic head resections (lap-PPPD) performed between March and September 2010. The operations were performed using a hybrid approach with complete laparoscopic pylorus-preserving pancreatic head resection and successive reconstruction via a small retrieval incision. Perioperative outcome was compared to 605 open pancreatic head resections (1997-2010).

RESULTS

In the group lap-PPPD 3 out of 9 conversions had to be performed due to oncologic reasons. There were no significant differences in perioperative outcome when comparing open-PPPD to lap-PPPD.

CONCLUSION

Laparoscopic pancreatic head resection with hybrid open reconstruction combines the potential advantages of laparoscopic resection with the safety of an open pancreatic anastomosis. Even at the beginning of the learning curve the procedure can be performed with no concessions to safety or duration of the operation.

Ghrelin PYY 3-36 serum changes in left ventricular hypertrophic, insulin-resistant, hypertensive obese patients

AIM

Hypertension is a major health problem and is usually associated with common conditions such as obesity, which contribute to clinical cardiac dysfunction. The role of energy homeostasis hormones such as ghrelin and PYY 3-36 in cardiovascular function remains incompletely understood. Therefore, the aim of our study was to explore the potential differences in concentrations of ghrelin forms and PYY 3-36 circulating in obese patients with grade 1 and grade 2 hypertension, with higher and lower BMI and without and with insulin resistance as well as to determine whether these hormones may be associated with left ventricular hypertrophy.

METHODS

A total of 142 adult subjects were studied in three subgroups: lean (BMI < 25 kg/m(2)) normotensive subjects and obese subjects (BMI 30.0-34.9 kg/m(2)), and obese subjects (BMI 35.0-39.9 kg/m(2)) under hypertensive treatment for at least 9 years. Fasting blood glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), lipid profile, urinic acid, acylated ghrelin (A-Ghr), total ghrelin (T-Ghr), and PYY 3-36 were measured. Insulin resistance was determined by the homeostasis model assessment of insulin resistance (HOMA-IR). We also echocardiographically assessed left ventricular mass (LVM) index (LVMI = LVM/height(2.7)). We evaluated the association between plasma T-Ghr, A-Ghr, PYY 3-36 levels with LVMI and other measured factors using univariate and multivariate analysis.

RESULTS

There were significant differences between BMI, waist circumference (WC), LVMI, hs-CRP and A-Ghr/nonacylated ghrelin (NA-Ghr) ratio (in the two obese subgroups. There was no significant difference between T-Ghr, A-Ghr and PYY 3-36 levels between obese subgroups. T-Ghr and PYY 3-36 were significantly lower in obese patients than in the control group, whereas A-Ghr levels did not differ between obese and controls. A-Ghr/NA-Ghr ratio was significantly higher in patients with second-degree hypertension and BMI 35.0-39.9 kg/m(2) than in patients with first-degree hypertension and BMI 30.0-34.9 kg/m(2). There were negative associations between T-Ghr, NA-Ghr or PYY 3-36 and LVMI (r = -0.49, p = 0.0001; r = -0.47, p = 0.0001; or r = -0.18, p = 0.029, respectively) and positive association between A-Ghr/NA-Ghr ratio and LVMI (r = 0.3, p = 0.0003). T-Ghr and NA-Ghr, were associated negatively with fasting insulin (r = -0.31, p = 0.0025; and r = -0.36, p = 0.001, repectively), while A-Ghr/NA-Ghr ratio was positively associated with BMI and fasting insulin (r = 0.23, p = 0.041; r = 0.3, p = 0.0045, respectively). T-Ghr, A-Ghr, and NAGhr were also inversely related to HOMA-IR indices in obese patients (r = -0.43, p = 0.001; r = -0.32, p = 0.0359; r = -0.35, p = 0.001, respectively). In insulin-resistant obese subjects T-Ghr and NA-Ghr correlated negatively with HOMA-IR (r = -0.34, p = 0.0015; r = -0.28, p = 0.0116, respectively). LVMI was associated negatively with T-Ghr, NA-Ghr and PYY 3-36 (r = -0.49, p = 0.0001; r = -0.47, p = 0.0001; r = -0.18, p = 0.029, respectively). In addition, LVMI was positively associated with A-Ghr/NA-Ghr ratio (r = 0.30, p = 0.0003).

CONCLUSION

Plasma ghrelin forms and PYY 3-36 levels are associated with LVMI. These associations indicate a possible interaction between gut peptides and the cardiovascular system in hypertension and obesity.