The Impact of Minimally Invasive Surgical Techniques

An intuitive guidewire control mechanism for robotic intervention

PURPOSE

Teleoperated Interventional Robotic systems (TIRs) are developed to reduce radiation exposure and physical stress of the physicians and enhance device manipulation accuracy and stability. Nevertheless, TIRs are not widely adopted, partly due to the lack of intuitive control interfaces. Current TIR interfaces like joysticks, keyboards, and touchscreens differ significantly from traditional manual techniques, resulting in a shallow, longer learning curve. To this end, this research introduces a novel control mechanism for intuitive operation and seamless adoption of TIRs.

METHODS

An off-the-shelf medical torque device augmented with a micro-electromagnetic tracker was proposed as the control interface to preserve the tactile sensation and muscle memory integral to interventionalists' proficiency. The control inputs to drive the TIR were extracted via real-time motion mapping of the interface. To verify the efficacy of the proposed control mechanism to accurately operate the TIR, evaluation experiments using industrial grade encoders were conducted.

RESULTS

A mean tracking error of 0.32 ± 0.12 mm in linear and 0.54 ± 0.07° in angular direction were achieved. The time lag in tracking was found to be 125 ms on average using pade approximation. Ergonomically, the developed control interface is 3.5 mm diametrically larger, and 4.5 g. heavier compared to traditional torque devices.

CONCLUSION

With uncanny resemblance to traditional torque devices while maintaining results comparable to state-of-the-art commercially available TIRs, this research successfully provides an intuitive control interface for potential wider clinical adoption of robot-assisted interventions.

Sensorimotor Challenges in Minimally Invasive Surgery: A Theoretically-Oriented Review

OBJECTIVE

This review surveys the literature on sensorimotor challenges impacting performance in laparoscopic minimally invasive surgery (MIS).

BACKGROUND

Despite its well-known benefits for patients, achieving proficiency in MIS can be challenging for surgeons due to many factors including altered visual perspectives and fulcrum effects in instrument handling. Research on these and other sensorimotor challenges has been hindered by imprecise terminology and the lack of a unified theoretical framework to guide research questions in the field.

METHOD

We conducted a systematic survey of the MIS literature, focusing on studies investigating sensorimotor challenges affecting laparoscopic performance. To provide a common foundation for cross-study comparisons, we propose a standardized taxonomy that distinguishes between different experimental paradigms used in the literature. We then show how the computational motor learning perspective provides a unifying theoretical framework for the field that can facilitate progress and motivate future research along clearer, hypothesis-driven lines.

RESULTS

The survey identified diverse sensorimotor perturbations in MIS, which can be effectively categorized according to our proposed taxonomy. Studies investigating monitor-, camera-, and tool-based perturbations were systematically analyzed, elucidating their impact on surgical performance. We also show how the computational motor learning perspective provides deeper insights and potential strategies to mitigate challenges.

CONCLUSION

Sensorimotor challenges significantly impact MIS, necessitating a systematic, empirically informed approach. Our proposed taxonomy and theoretical framework shed light on the complexities involved, paving the way for more structured research and targeted training approaches to enhance surgical proficiency.

APPLICATION

Understanding the sensorimotor challenges inherent to MIS can guide the design of improved training curricula and inform the configuration of setups in the operating room to enhance surgeon performance and ultimately patient outcomes. This review offers key insights for surgeons, educators, and researchers in surgical performance and technology development.

Open versus robot-assisted retroperitoneal tumors resection involving inferior vena cava, abdominal aorta, and renal hilum: a comparative study

INTRODUCTION

Surgery is currently the only effective treatment for retroperitoneal tumors that do not involve any specific organ. The use of robots for removing both benign and malignant retroperitoneal tumors is considered safe and feasible. However, there is insufficient evidence to determine whether robotic retroperitoneal tumor resection (RMBRs) is superior to open retroperitoneal malignant resection (OMBRs). This study compares the short-term outcomes of robotic excision of benign and malignant retroperitoneal tumors with open excision of the same-sized tumors.

METHODS

The study compared demographics and outcomes of patients who underwent robotic resection (n = 54) vs open resection (n = 54) of retroperitoneal tumors between March 2018 and December 2022. A 1:1 matching analysis was conducted to ensure a fair comparison.

RESULTS

The study found that RBMRs resulted in reduced operative time (OT), estimated blood loss (EBM), and postoperative hospital stay (PSH) when compared to OBMRs. Additionally, RBMRs reduced EBL, PHS, and OT for patients with malignant tumor involvement in major vessels. No significant differences were found in tumor size, blood transfusion rate, and morbidity rate between the RBMRs and OBMRs groups.

CONCLUSION

When comparing RMBRs to OMBRs, it was observed that RMBR was associated with lower (EBL), shorter postoperative hospital stays (PHS), and reduced operative time (OT) in a specific group of patients with both benign and malignant tumors.

Open Minimally Invasive Parathyroidectomy Versus Minimally Invasive Video-Assisted Parathyroidectomy: A Systematic Review and Meta-Analysis

Various minimally invasive techniques exist for surgical parathyroidectomy. The aim of this study was to conduct a meta-analysis comparing two popular minimally invasive techniques: minimally invasive video-assisted parathyroidectomy (MIVAP) and open minimally invasive parathyroidectomy (OMIP). An extensive search was conducted of online databases to identify all previous studies that had compared MIVAP and OMIP. The primary outcome measures considered were visual analog scale (VAS) score 24 hours postoperatively, conversion of operation (to open), failure rate and analgesic consumption. The data from these studies was extracted and compiled into a meta-analysis. The literature search yielded 104 studies of which four were included, enrolling 903 patients in this analysis. A significant difference was found regarding rates of conversion to open parathyroidectomy between the two groups, with the OMIP group demonstrating fewer conversions (MD = 3.52, CI = (2.04-6.08), P< 0.00001). No statistically significant differences were found between the two groups when comparing postoperative VAS scores at 24 hours (MD = -1.75, CI = (-9.8-6.3), P = 0.67), consumption of analgesia (OR = 0.49, CI = 0.07-3.54, P = 0.48) or failure rates (OR = 1.81, CI = 0.58-5.72, P = 0.31). OMIP was seen to require less need to convert to open parathyroidectomy with shorter operative times, while similar complication rates and scar lengths to MIVAP. More studies are required to evaluate the superior technique for parathyroidectomy.

Soft tissue surgical robot for minimally invasive surgery: a review

Purpose

The current state of soft tissue surgery robots is surveyed, and the key technologies underlying their success are analyzed. State-of-the-art technologies are introduced, and future directions are discussed.

Methods

Relevant literature is explored, analyzed, and summarized.

Results

Soft tissue surgical robots had rapidly spread in the field of laparoscopic surgery based on the multi-degree-of-freedom movement of intra-abdominal surgical tools and stereoscopic imaging that are not possible in conventional surgery. The three key technologies that have made surgical robots successful are wire-driven mechanisms for multi-degree-of-freedom movement, master devices for intuitive remote control, and stereoscopic imaging technology. Recently, human-robot interaction technologies have been applied to develop user interfaces such as vision assistance and haptic feedback, and research on autonomous surgery has begun.

Conclusion

Robotic surgery not only replaces conventional laparoscopic surgery but also allows for complex surgeries that are not possible with laparoscopic surgery. On the other hand, it is also criticized for its high cost and lack of clinical superiority or patient benefit compared to conventional laparoscopic surgery. As various robots compete in the market, the cost of surgical robots is expected to decrease. Surgical robots are expected to continue to evolve in the future due to the need to reduce the workload of medical staff and improve the level of care demanded by patients.

M1 transcranial direct current stimulation augments laparoscopic surgical skill acquisition

The acquisition of basic surgical skills is a key component of medical education and trainees in laparoscopic surgery typically begin developing their skills using simulation box trainers. However, despite the advantages of simulation surgical training, access can be difficult for many trainees. One technique that has shown promise to enhance the deliberate practice of motor skills is transcranial electric stimulation (tES). The purpose of this study was to assess the impact of transcranial direct current stimulation (tDCS) on training induced improvements and retention of traditional time and kinematic based laparoscopic surgical skill metrics. Forty-nine medical students were randomly allocated to a neurostimulation or sham group and completed 5 training sessions of a bead transfer and threading laparoscopic task. Participants in both the sham and stimulation groups significantly improved their time and kinematic performance on both tasks following training. Although we did find that participants who received M1 tDCS saw greater performance benefits in response to training on a bead transfer task compared to those receiving sham stimulation no effect of neurostimulation was found for the threading task. This finding raises new questions regarding the effect that motor task complexity has on the efficacy of neurostimulation to augment training induced improvement and contributes to a growing body of research investigating the effects of neurostimulation on the sensory-motor performance of laparoscopic surgical skill.

Artificial intelligence and automation in endoscopy and surgery

Modern endoscopy relies on digital technology, from high-resolution imaging sensors and displays to electronics connecting configurable illumination and actuation systems for robotic articulation. In addition to enabling more effective diagnostic and therapeutic interventions, the digitization of the procedural toolset enables video data capture of the internal human anatomy at unprecedented levels. Interventional video data encapsulate functional and structural information about a patient's anatomy as well as events, activity and action logs about the surgical process. This detailed but difficult-to-interpret record from endoscopic procedures can be linked to preoperative and postoperative records or patient imaging information. Rapid advances in artificial intelligence, especially in supervised deep learning, can utilize data from endoscopic procedures to develop systems for assisting procedures leading to computer-assisted interventions that can enable better navigation during procedures, automation of image interpretation and robotically assisted tool manipulation. In this Perspective, we summarize state-of-the-art artificial intelligence for computer-assisted interventions in gastroenterology and surgery.

Fabrication of Bilayer Magnetically Actuated L-Shaped Microrobot Based on Chitosan via Photolithography

Magnetically actuated microrobots showed increasing potential in various fields, especially in the biomedical area, such as invasive surgery, targeted cargo delivery, and treatment. However, it remains a challenge to incorporate biocompatible natural polymers that are favorable for practical biomedical applications. In this work, bilayer magnetic microrobots with an achiral planar design were fabricated using a biocompatible natural polymer and Fe₃O₄ nanoparticles through the photolithography by applying the layer-by-layer method. The microrobots consisted of a magnetic bottom layer and a photo-crosslinked chitosan top layer. The SEM results showed that the microrobot processed the L-shaped planar structure with the average width, length, and thickness of 99.18 ± 5.11 μm, 189.56 ± 11.37 μm, and 23.56 ± 4.08 μm, respectively. Moreover, microrobots actuated using a three-dimensional (3D) Helmholtz coil system was characterized and reached up to an average maximum velocity of 325.30 μm/s and a step-out frequency of 14 Hz. Furthermore, the microrobots exhibited excellent cell biocompatibility towards L929 cells in the CCK-8 assay. Therefore, the development of bi-layered chitosan-based microrobots offers a general solution for using magnetic microrobots in biomedical applications by providing an easy-to-fabricate, highly mobile microrobotic platform with the incorporation of biocompatible natural polymers for enhanced biocompatibility.

Deployable Tubular Mechanisms Integrated with Magnetic Anchoring and Guidance System

Deployable mechanism has received more attention in the medical field due to its simple structure, dexterity, and flexibility. Meanwhile, the advantages of the Magnetic Anchoring and Guidance System (MAGS) are further highlighted by the fact that the operators can remotely control the corresponding active and passive magnetic parts in vivo. Additionally, MAGS allows the untethered manipulation of intracorporeal devices. However, the conventional instruments in MAGS are normally rigid, compact, and less flexible. Therefore, to solve this problem, four novel deployable tubular mechanisms, Design 1 (Omega-shape mechanism), Design 2 (Fulcrum-shape mechanism), Design 3 (Archway-shape mechanism), and Design 4 (Scissor-shape mechanism) in this paper, are proposed integrated with MAGS to realize the laser steering capability. Firstly, this paper introduces the motion mechanism of the four designs and analyzes the motion characterization of each structure through simulation studies. Further, the prototypes of four designs are fabricated using tubular structures with embedded magnets. The actuation success rate, the workspace characterization, the force generation and the load capability of four mechanisms are tested and analyzed based on experiments. Then, the demonstration of direct laser steering via macro setup shows that the four mechanisms can realize the laser steering capability within the error of 0.6 cm. Finally, the feasibility of indirect laser steering via a macro-mini setup is proven. Therefore, such exploration demonstrates that the application of the deployable tubular mechanisms integrated with MAGS towards in vivo treatment is promising.

Design and clinical application of injectable hydrogels for musculoskeletal therapy

Musculoskeletal defects are an enormous healthcare burden and source of pain and disability for individuals. With an aging population, the proportion of individuals living with these medical indications will increase. Simultaneously, there is pressure on healthcare providers to source efficient solutions, which are cheaper and less invasive than conventional technology. This has led to an increased research focus on hydrogels as highly biocompatible biomaterials that can be delivered through minimally invasive procedures. This review will discuss how hydrogels can be designed for clinical translation, particularly in the context of the new European Medical Device Regulation (MDR). We will then do a deep dive into the clinically used hydrogel solutions that have been commercially approved or have undergone clinical trials in Europe or the United States. We will discuss the therapeutic mechanism and limitations of these products. Due to the vast application areas of hydrogels, this work focuses only on treatments of cartilage, bone, and the nucleus pulposus. Lastly, the main steps toward clinical translation of hydrogels as medical devices are outlined. We suggest a framework for how academics can assist small and medium MedTech enterprises conducting the initial clinical investigation and post‐market clinical follow‐up required in the MDR. It is evident that the successful translation of hydrogels is governed by acquiring high‐quality pre‐clinical and clinical data confirming the device mechanism of action and safety.

A comparative study of peri-operative outcomes for 100 consecutive post-chemotherapy and primary robot-assisted and open retroperitoneal lymph node dissections

PURPOSE

To describe and compare differences in peri-operative outcomes of robot-assisted (RA-RPLND) and open (O-RPLND) retroperitoneal lymph node dissection performed by a single surgeon where chemotherapy is the standard initial treatment for Stage 2 or greater non-seminomatous germ cell tumour.

METHODS

Review of a prospective database of all RA-RPLNDs (28 patients) and O-RPLNDs (72 patients) performed by a single surgeon from 2014 to 2020. Peri-operative outcomes were compared for patients having RA-RPLND to all O-RPLNDs and a matched cohort of patients having O-RPLND (20 patients). Further comparison was performed between all patients in the RA-RPLND group (21 patients) and matched O-RPLND group (18 patients) who had previous chemotherapy. RA-RPLND was performed for patients suitable for a unilateral template dissection. O-RPLND was performed prior to the introduction of RA-RPLND and for patients not suitable for RA-RPLND after its introduction.

RESULTS

RA-RPLND showed improved peri-operative outcomes compared to the matched cohort of O-RPLND-median blood loss (50 versus 400 ml, p < 0.00001), operative duration (150 versus 195 min, p = 0.023) length-of-stay (1 versus 5 days, p < 0.00001) and anejaculation (0 versus 4, p = 0.0249). There was no statistical difference in complication rates. RA-RPLND had lower median lymph node yields although not significant (9 versus 13, p = 0.070). These improved peri-operative outcomes were also seen in the post-chemotherapy RA-RPLND versus O-RPLND analysis. There were no tumour recurrences seen in either group with median follow-up of 36 months and 60 months, respectively.

CONCLUSIONS

Post-chemotherapy RA-RPLND may have decreased blood loss, operative duration, hospital length-of-stay and anejaculation rates in selected cases and should, therefore, be considered in selected patients. Differences in oncological outcomes require longer term follow-up.

Population pharmacokinetic model selection assisted by machine learning

A fit-for-purpose structural and statistical model is the first major requirement in population pharmacometric model development. In this manuscript we discuss how this complex and computationally intensive task could benefit from supervised machine learning algorithms. We compared the classical pharmacometric approach with two machine learning methods, genetic algorithm and neural networks, in different scenarios based on simulated pharmacokinetic data. Genetic algorithm performance was assessed using a fitness function based on log-likelihood, whilst neural networks were trained using mean square error or binary cross-entropy loss. Machine learning provided a selection based only on statistical rules and achieved accurate selection. The minimization process of genetic algorithm was successful at allowing the algorithm to select plausible models. Neural network classification tasks achieved the most accurate results. Neural network regression tasks were less precise than neural network classification and genetic algorithm methods. The computational gain obtained by using machine learning was substantial, especially in the case of neural networks. We demonstrated that machine learning methods can greatly increase the efficiency of pharmacokinetic population model selection in case of large datasets or complex models requiring long run-times. Our results suggest that machine learning approaches can achieve a first fast selection of models which can be followed by more conventional pharmacometric approaches.

Urology Residents Simulation Training Improves Clinical Outcomes in Laparoscopic Partial Nephrectomy

BACKGROUND

Partial nephrectomy (PN) is the preferred modality of treatment for small renal masses. Laparoscopic partial nephrectomy (LPN) has been adopted worldwide and a fundamental role is played by surgical skills. The need for skill instruction outside the operating room is well recognized in the modern models of surgery residency training. We aim to investigate the impact of residents' laparoscopic surgical skills training on the successful implementation of LPN in a reference public teaching hospital in southern Brazil.

METHODS

We accessed all patients undergoing LPN by senior's urology residents at Hospital de Clínicas de Porto Alegre. Patients were stratified in 2 periods of time named 'LPN eras' 1 and 2, to report the training impact on the outcome. LPN era 1 was from October 2012 to February 2017 and LPN era 2 from March 2017 to June 2019. All the senior residents of LPN era 2 followed a simulation training divided into 4 years with a total training time of 244 hours before performing the LPN. Residents from LPN era 1 did not have simulation training.

RESULTS

124 patients underwent LPN during the study period, 53 (42.7%) of those were performed in LPN era 1 and 71 (57.3%) in LPN era 2. Baseline characteristics of the patients in the two groups were similar. The training performed by LPN era 2 residents was able to significantly reduce estimated blood loss, ischemia time and LOS with p value respectively 0.007, 0.001 and 0.001. LPN era 2 group also reached Trifecta in 77.5% of patients, being significantly more than in the LPN era 1 (p = 0.007).

CONCLUSIONS

Simulation in residents surgical training was able to improve clinical outcomes in LPN. These data reinforce the fundamental importance of adequate residents training before performing surgery on a patient.

Deformation of the Pelvic Arteries Caused by Pneumoperitoneum and Postural Changes in an Animal Model

BACKGROUND/AIM

We investigated pelvic arterial deformation and shift due to intraoperative pneumoperitoneum and postural changes in an animal model.

MATERIALS AND METHODS

Computed tomography images of pigs were acquired in different body positions (supine, head down at 5° and 10°, right lateral recumbent at 5° and 15°) before and after insufflation. We used a free software (3D Slicer) for image analysis. After landmark registration using 10 markers inserted into the pelvis, pelvic arterial deformation and shift of seven arterial bifurcation points were evaluated. The distance moved was the target registration error (TRE) from the points registered in the supine position. Fiducial registration error (FRE) was measured using the 10 pelvic markers.

RESULTS

TRE average from postural changes ranged from 0.7 to 1.2 mm and was 1.4 mm due to pneumoperitoneum. TRE and FRE averages were 2.1 mm and 0.2 mm, respectively.

CONCLUSION

The pelvis was useful for registering anatomical landmarks.

Inducing pilon fractures in human cadaveric specimens depending on the injury mechanism: a fracture simulation

BACKGROUND

Operative management of pilon fractures, especially high-energy compression injuries, is a challenge. Operative education is of vital importance to handle these entities. Not rarely, it is cut by economics and staff shortage. As public awareness toward operative competence rises, surgical cadaver courses that provide pre-fractured specimens can improve realism of teaching scenarios. The aim of this study is to introduce a realistic pilon fracture simulation setup regarding the injury mechanism.

MATERIALS AND METHODS

8 cadaveric specimens (two left, six right) were fixed onto a custom drop-test bench in dorsiflexion (20°) and light supination (10°). The proximal part of the lower leg was potted, and the specimen was exposed to a high energetic impulse via an axial impactor. CT imaging was performed after fracture simulation to detect the exact fracture patterns and to classify the achieved fractures by two independent trauma surgeons. (AO/OTA recommendations and the Rüedi/Allgöwer).

RESULTS

All cadaveric specimens could be successfully fractured: 6 (75%) were identified as a 43-C fracture and 2 (25%) as 43-B fracture type. Regardless of the identical mechanism two different kinds of fracture types were reported. In five cases (62.5%), the fibula was also fractured and in three specimens, a talus fracture was described. There was no statistically significant correlation found regarding Hounsfield Units (HU) and age as well as HU and required kinetic energy.

CONCLUSION

A high energetic axial impulse on a fixed ankle specimen in light dorsiflexion (20°) and supination (10°) induced by a custom-made drop-test bench can successfully simulate realistic pilon fractures in cadaveric specimens with intact soft tissue envelope. Although six out of eight fractures (75%) were classified as a 43-C fracture and despite putting a lot of effort into the mechanical setup, we could not achieve an absolute level of precision. Therefore, we suggest that the injury mechanism is most likely a combination of axial loading, shear and rotation.

LEVEL OF EVIDENCE

III.

Are Surgeons Working Smarter or Harder? A Systematic Review Comparing the Physical and Mental Demands of Robotic and Laparoscopic or Open Surgery

BACKGROUND

Minimally invasive surgical techniques such as robotic surgical platforms have provided favourable outcomes for patients, but the impact on surgeons is not well described. This systematic review aims to synthesize and evaluate the physical and mental impact of robotic surgery on surgeons compared to standard laparoscopic or open surgery.

METHODS

A search strategy was developed to identify peer-reviewed English articles published from inception to end of December 2019 on the following databases: MEDLINE, PubMed, PsycINFO and Embase. The articles were assessed using a modified Newcastle-Ottawa tool.

RESULTS

Of the 6563 papers identified, 30 studies were included in the qualitative synthesis of this review. Most of the included studies presented a high risk of bias. A total of 13 and 21 different physical and mental tools, respectively, were used to examine the impact on surgeons. The most common tool used to measure physical and mental demand were surface electromyography (N = 9) and the NASA Task Load Index (NASA-TLX; N = 8), respectively. Majority of studies showed mixed results for physical (N = 10) and mental impact (N = 7). This was followed by eight and six studies favouring RS over other surgical modalities for physical and mental impact, respectively.

CONCLUSION

Most studies showed mixed physical and mental outcomes between the three surgical modalities. There was a high risk of bias and methodological heterogeneity. Future studies need to correlate mental and physical stress with long-term impact on the surgeons.

Examining the impact of psychological distress on short-term postoperative outcomes after elective endovascular aneurysm repair (EVAR)

PURPOSE

Preoperative psychological factors have an impact on postoperative outcomes and there is a paucity of research in vascular surgery. The objective of this study was to examine the impact of preoperative psychological factors on short-term postoperative outcomes in an infrarenal endovascular aneurysm repair (EVAR) cohort.

METHODS

A prospective, multi-centre observational study was conducted across three vascular units in England. English-speaking participants who were older than 18 years, able to provide informed consent and awaiting an elective standard infrarenal EVAR were eligible for the study. A total of 46 patients undergoing elective infrarenal AAA repair were assessed preoperatively with the State Trait Anxiety Inventory (STAI), Beck's Depression Inventory (BDI-II) and Life Orientation Test-Revised (LOT-R). Data on five short-term postoperative outcomes was collected and analysed using Spearman's rank correlations.

RESULTS

Higher preoperative anxiety levels (ρ = 0.38, p = 0.01), and depression scores (ρ = 0.36, p = 0.02) were moderately correlated with an increased length of postoperative critical care stay. Higher levels of preoperative depression were moderately correlated with greater postoperative opioid analgesia use (ρ = 0.34, p = 0.02). No correlation was witnessed between optimism scores and postoperative outcomes. No correlation was witnessed with respect to total length of stay, number of complications, or time to mobilisation.

CONCLUSIONS

There is a potential link between preoperative psychological well-being and short-term postoperative outcomes in an EVAR cohort. Further work is necessary to validate this link and examine the role of preoperative interventions in optimising the psychological well-being of patients undergoing EVAR.

Inequalities in access to minimally invasive general surgery: a comprehensive nationwide analysis across 20 years

Background

Minimally invasive surgery (MIS) has profoundly changed standards of care and lowered perioperative morbidity, but its temporal implementation and factors favoring MIS access remain elusive. We aimed to comprehensibly investigate MIS adoption across different surgical procedures over 20 years, identify predictors for MIS amenability and compare propensity score-matched outcomes among MIS and open surgery.

Methods

Nationwide retrospective analysis of all hospitalizations in Switzerland between 1998 and 2017. Appendectomies (n = 186,929), cholecystectomies (n = 57,788), oncological right (n = 9138) and left hemicolectomies (n = 21,580), rectal resections (n = 13,989) and gastrectomies for carcinoma (n = 6606) were included. Endpoints were assessment of temporal MIS implementation, identification of predictors for MIS access and comparison of propensity score-matched outcomes among MIS and open surgery.

Results

The rates of MIS increased for all procedures during the study period (p ≤ 0.001). While half of all appendectomies were performed laparoscopically by 2005, minimally invasive oncological colorectal resections reached 50% only by 2016. Multivariate analyses identified older age (p ≤ 0.02, except gastrectomy), higher comorbidities (p ≤ 0.001, except rectal resections), lack of private insurance (p ≤ 0.01) as well as rural residence (p ≤ 0.01) with impaired access to MIS. Rural residence correlated with low income regions (p ≤ 0.001), which themselves were associated with decreased MIS access. Geographical mapping confirmed strong disparities for rural and low-income areas in MIS access. Matched outcome analyses revealed benefits of MIS for length of stay, decreased surgical site infection rates for MIS appendectomies and cholecystectomies and higher mortality for open cholecystectomies. No consistent morbidity or mortality benefit for MIS compared to open colorectal resections was observed.

Conclusion

Unequal access to MIS exists in disfavor of older and more comorbid patients and those lacking private insurance, living in rural areas, and having lower income. Efforts should be made to ensure equal MIS access regardless of socioeconomic or geographical factors.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-08123-0) contains supplementary material, which is available to authorized users.

Teaching surgery novices and trainees advanced laparoscopic suturing: a trial and tribulations

INTRODUCTION

The benefits of minimally invasive surgery are numerous; however, considerable variability exists in its application and there is a lack of standardized training for important advanced skills. Our goal was to determine whether participation in an advanced laparoscopic curriculum (ALC) results in improved laparoscopic suturing skills.

METHODS AND PROCEDURES

Study design was a prospective, randomized controlled trial. Surgery novices and trainees underwent baseline FLS training and were pre-tested on bench models. Participants were stratified by pre-test score and randomized to undergo either further FLS training (control group) or ALC training (intervention group). All were post-tested on the same bench model. Tests for differences between post-test scores of cohorts were performed using least squared means. Multivariable regression identified predictors of post-test score, and Wilcoxon rank sum test assessed for differences in confidence improvement in laparoscopic suturing ability between groups.

RESULTS

Between November 2018 and May 2019, 25 participants completed the study (16 females; 9 males). After adjustment for relevant variables, participants randomized to the ALC group had significantly higher post-test scores than those undergoing FLS training alone (mean score 90.50 versus 82.99, p = 0.001). The only demographic or other variables found to predict post-test score include level of training (p = 0.049) and reported years of video gaming (p = 0.034). There was no difference in confidence improvement between groups.

CONCLUSIONS

Training using the ALC as opposed to basic laparoscopic skills training only is associated with superior advanced laparoscopic suturing performance without affecting improvement in reported confidence levels. Performance on advanced laparoscopic suturing tasks may be predicted by lifetime cumulative video gaming history and year of training but does not appear to be associated with other factors previously studied in relation to basic laparoscopic skills, such as surgical career aspiration or musical ability.

Inducing life-like distal radius fractures in human cadaveric specimens: a tool for enhanced surgical training

INTRODUCTION

Surgical education consists often times of a discrepancy between necessary amount of provided operative teaching and amount of organizational and ward duties. Operative education is often cut to a minimum. As public awareness toward surgical competence raises, so must the educational system. Courses that provide pre-fractured cadaveric specimens can facilitate surgical teaching realistically, prior to operating on living patients. The aim of this study is to introduce a realistic distal radius fracture simulation setup.

MATERIALS AND METHODS

12 cadaveric specimens (3 male, 9 female) were fixed onto a custom drop-test-bench in the hyperextension of the wrist. The forearm was cut midway between elbow and carpus. The distal part of the forearm was potted, and the specimen was exposed to a high energetic impulse. CT imaging was performed after fracture simulation to detect the exact fracture patterns. We used the AO/ASIF recommendations and four-corner concept to classify the achieved fractures by two independent trauma surgeons.

RESULTS

All cadaveric specimens could be successfully fractured. 11 fractures were classified as type 23C3.2 and one was classified as type 23C3.3, as additional fracture of diaphysis occurred. Subclassification according to the four-corner concept showed all fractures to be type C. A concomitant ulnar styloid fracture was observed in 4 cases. Furthermore, all cases showed at least one fragment involving the sigmoid notch. There was no statistically significant correlation found regarding Hounsfield Units (HU) and age (p value 0.402), as well as HU and required kinetic energy (p value 0.063).

CONCLUSION

A high energetic impulse induced by a custom-made drop-test bench can successfully simulate realistic distal radius fractures in cadaveric specimens with intact soft tissue. Furthermore, these pre-fractured specimens can be utilized in surgical education to provide a teaching experience as realistic as possible without harming living patients.

Nursing performance in robotic surgeries: integrative review

OBJECTIVE

To know the scientific production on the performance of the nursing staff in robotic surgeries, identifying the role of the nurse in the three perioperative periods.

METHODS

Integrative review, search in the databases National Library of Medicine, National Institutes of Health, Scientific Electronic Library Online and Biblioteca Virtual em Saúde, performed from June to September, 2017; 17 selected articles met the inclusion criteria.

RESULTS

Most articles were published in foreign journals in English, nine in the United States, classified with evidence level of 4 and 5. The role of nursing in the perioperative period was identified, related mainly to patient safety. The most mentioned perioperative period in the articles was the intraoperative, with greater concern in the positioning of the patient.

CONCLUSION

The nursing performance and patient safety in robotic surgeries are similar to the ones in major surgeries, requiring from the patient a specific knowledge on the setting and preparation of the robot.

3D-Printed Biodegradable Microswimmer for Theranostic Cargo Delivery and Release

Untethered mobile microrobots have the potential to leverage minimally invasive theranostic functions precisely and efficiently in hard-to-reach, confined, and delicate inner body sites. However, such a complex task requires an integrated design and engineering, where powering, control, environmental sensing, medical functionality, and biodegradability need to be considered altogether. The present study reports a hydrogel-based, magnetically powered and controlled, enzymatically degradable microswimmer, which is responsive to the pathological markers in its microenvironment for theranostic cargo delivery and release tasks. We design a double-helical architecture enabling volumetric cargo loading and swimming capabilities under rotational magnetic fields and a 3D-printed optimized 3D microswimmer (length = 20 μm and diameter = 6 μm) using two-photon polymerization from a magnetic precursor suspension composed from gelatin methacryloyl and biofunctionalized superparamagnetic iron oxide nanoparticles. At normal physiological concentrations, we show that matrix metalloproteinase-2 (MMP-2) enzyme could entirely degrade the microswimmer in 118 h to solubilized nontoxic products. The microswimmer rapidly responds to the pathological concentrations of MMP-2 by swelling and thereby boosting the release of the embedded cargo molecules. In addition to delivery of the drug type of therapeutic cargo molecules completely to the given microenvironment after full degradation, microswimmers can also release other functional cargos. As an example demonstration, anti-ErbB 2 antibody-tagged magnetic nanoparticles are released from the fully degraded microswimmers for targeted labeling of SKBR3 breast cancer cells in vitro toward a potential future scenario of medical imaging of remaining cancer tissue sites after a microswimmer-based therapeutic delivery operation.

Disposable Stiffness Sensor for Endoscopic Examination

Since direct manual palpation is not possible in minimally invasive procedures, there is an active field of applied research which aims to retrieve the human sense of touch and feedback tissue properties through artificial tactile feedback. This paper presents an innovative stiffness sensor to be embedded at the tip of a commercial endoscopic camera. The sensor structure is based on multiple cantilever beams, which act as springs with different stiffness when indented into soft tissue. Geometric features mounted on the beams are tracked during physical contact. Movements of thecantilevers result in shape variations of the features in the camera images. The feature size is then segmented and related to the force exerted into the contact location. As beams of different elasticity are integrated, it is possible to estimate the stiffness properties of the soft tissue by employing only visual information. In this paper, Finite Element Analysis (FEA) was implemented to simulate and estimate how contact forces will affect the material and design of the prototype. A calibration device has been developed and used to validate the outcome of the FEA simulations. An experimental test showed the ability of the proposed mechanism to compute the stiffness of a soft phantom.

The Implementation Gap in Laparoscopic Simulation Training

BACKGROUND AND AIMS

Simulation-based training in laparoscopy can improve patient safety and efficiency of care, but it depends on how it is used. Research in medical education has moved from demonstrating transferability of simulation training to the operating room to how to best implement it. This study aims to investigate how simulation-based training in laparoscopy has been implemented Scandinavia.

MATERIAL AND METHODS

An online survey was sent out to medical doctors at surgical, gynecological, and urological departments at 138 hospitals in Denmark, Norway, and Sweden. The questionnaire included questions on respondents' baseline characteristics, opinions, access, and actual use of simulation-based training in laparoscopy.

RESULTS

In total, 738 respondents completed the survey. Of these, 636 (86.2%) of respondents agreed or strongly agreed that simulation-based training in laparoscopy should be mandatory. A total of 602 (81.6%) had access to simulation-based training in laparoscopy. Of the total 738 respondents, 141 (19.1%) were offered structured training courses, 129 (17.5%) were required to reach a predefined level of competency, and 66 (8.9%) had mandatory courses in laparoscopy. In all, 72 (9.8%) had never used simulation-based training in laparoscopy.

CONCLUSION

An implementation gap in laparoscopic simulation-based training still exists in Scandinavia. Simulation equipment is generally available, but there is a lack of structured simulation-based training.

Minimally invasive orthognathic surgery: a systematic review

Minimally invasive techniques are currently applied in many oral and maxillofacial surgical procedures, including orthognathic surgery. A systematic review on the application of potentially minimally invasive procedures in orthognathic surgery was performed to provide a clear overview of the relevant published data. Articles in English on minimally invasive orthognathic procedures, published in the scientific literature, were obtained from the PubMed, Embase, and Cochrane Library databases, and an additional manual search (revised 31 December 2016). After screening the abstracts and applying the eligibility criteria, 403 articles were identified. All articles reporting the potential for minimally invasive orthognathic surgery were included (n=44). The full papers were evaluated in detail and categorized as articles on a minimally invasive surgical approach (n=4), endoscopically assisted orthognathic procedures (n=17), or the use of a piezoelectric device in orthognathic surgery (n=25); two articles were each included in two categories. Although a small incision and minimal dissection is the basic principle of a minimally invasive technique, most articles (90.9%) reported the endoscope and piezoelectric instrument as important tools in minimally invasive orthognathic surgery. Evidence from available studies suggests that patients undergoing minimally invasive orthognathic surgery have less morbidity and make a faster recovery. Further research should aim to obtain higher levels of evidence.

Modified approach for pediatric external cricopharyngeal myotomy

Pediatric cricopharyngeal achalasia is an uncommon but important cause of oropharyngeal dysphagia. Failure of upper esophageal sphincter relaxation is the currently understood pathophysiology. Therapies include balloon dilation, botulinum toxin injection, and endoscopic or open cricopharyngeal myotomy (CPM). Open CPM is usually performed at the posterior midline of the cricopharyngeus and can be a risky procedure given concern for esophageal perforation and damage to the recurrent laryngeal nerve. Here, we present a novel modified technique for open CPM using a superficial anterolateral transection approach in the case of a young male with refractory cricopharyngeal achalasia.

Improving the management of post-operative acute pain: priorities for change

Poor management of post-operative acute pain can contribute to medical complications including pneumonia, deep vein thrombosis, infection and delayed healing, as well as the development of chronic pain. It is therefore important that all patients undergoing surgery should receive adequate pain management. However, evidence suggests this is not currently the case; between 10% and 50% of patients develop chronic pain after various common operations, and one recent US study recorded >80% of patients experiencing post-operative pain. At the first meeting of the acute chapter of the Change Pain Advisory Board, key priorities for improving post-operative pain management were identified in four different areas. Firstly, patients should be more involved in decisions regarding their own treatment, particularly when fateful alternatives are being considered. For this to be meaningful, relevant information should be provided so they are well informed about the various options available. Good physician/patient communication is also essential. Secondly, better professional education and training of the various members of the multidisciplinary pain management team would enhance their skills and knowledge, and thereby improve patient care. Thirdly, there is scope for optimizing treatment. Examples include the use of synergistic analgesia to target pain at different points along pain pathways, more widespread adoption of patient-controlled analgesia, and the use of minimally invasive rather than open surgery. Fourthly, organizational change could provide similar benefits; introducing acute pain services and increasing their availability towards the 24 hours/day ideal, greater adherence to protocols, increased use of patient-reported outcomes, and greater receptivity to technological advances would all help to enhance performance and increase patient satisfaction. It must be acknowledged that implementing these recommendations would incur a considerable cost that purchasers of healthcare may be unwilling or unable to finance. Nevertheless, change is under way and the political will exists for it to continue.

Validity of a cross-specialty test in basic laparoscopic techniques (TABLT)

Background

Box trainer systems have been developed that include advanced skills such as suturing. There is still a need for a portable, cheap training and testing system for basic laparoscopic techniques that can be used across different specialties before performing supervised surgery on patients. The aim of this study was to establish validity evidence for the Training and Assessment of Basic Laparoscopic Techniques (TABLT) test, a tablet‐based training system.

Methods

Laparoscopic surgeons and trainees were recruited from departments of general surgery, gynaecology and urology. Participants included novice, intermediate and experienced surgeons. All participants performed the TABLT test. Performance scores were calculated based on time taken and errors made. Evidence of validity was explored using a contemporary framework of validity.

Results

Some 60 individuals participated. The TABLT was shown to be reliable, with an intraclass correlation coefficient of 0·99 (P < 0·001). ANOVA showed a difference between the groups with different level of experience (P < 0·001). The Bonferroni correction was used to confirm this finding. A Pearson's r value of 0·73 (P < 0·001) signified a good positive correlation between the level of laparoscopic experience and performance score. A reasonable pass–fail standard was established using contrasting groups methods.

Conclusion

TABLT can be used for the assessment of basic laparoscopic skills and can help novice surgical trainees in different specialties gain basic laparoscopic competencies.

Simple, cheap and valid

Retrospective assessment of the validity of robotic surgery in comparison to open surgery for pediatric choledochal cyst

PURPOSE

We evaluated the validity of robotic surgery (RS) for pediatric choledochal cyst (CC) in comparison to open surgery (OS).

MATERIALS AND METHODS

From January 2009 to April 2013, clinical data from 79 consecutive pediatric patients with CC, who underwent RS (n=36) or OS (n=43) performed by a single pediatric surgeon, were analyzed retrospectively.

RESULTS

In the RS group, the age of the patients was significantly older, compared to the OS group. Operation and anesthesia times were significantly longer in the RS group than the OS group. Fluid input rates to maintain the same urine output were significantly smaller in the RS group than the OS group. The American Society of Anesthesiologists (ASA) physical status, length of postoperative hospital stay, and the incidence of surgical complications did not differ significantly between the two groups.

CONCLUSION

Although early complications could not be avoided during the development of robotic surgical techniques, RS for pediatric CC showed results comparable to those for OS. We believe that RS may be a valid and alternative surgery for pediatric CC. After further development of robotic surgical systems and advancement of surgical techniques therewith, future prospective studies may reveal more positive results.

Endoscopic retrograde cholangiopancreatography in Ayrshire, Scotland: a comparison of two age cohorts

BACKGROUND AND AIMS

There is an increased trend in prevalence of pancreato-biliary disease in the elderly population. Consequently there is an increasing demand for endoscopic retrograde cholangiopancreatography (ERCP). The aims of this study were to compare ERCP outcomes in patients over 80 with those aged between 60 and 79 years and with the published literature.

METHODS AND RESULTS

Data were collected from a prospectively maintained database. All patients over the age of 60 years who underwent ERCP from May 2010 to May 2012 were identified. Two cohorts were formed, group A: 60-79 years (n = 66) and group B: > 80 years old (n = 49). Data on indications for ERCP, outcome, complications and repeat procedures were collected. One hundred and fifteen patients between the age of 60 and 92 years were identified. Group A had a total of 89 ERCPs and group B 69. Cannulation, overall procedure success, complication and mortality rates were comparable between both groups. Group B contained two cases of perforation with one associated mortality (1.4%) which did not reach statistical significance.

CONCLUSIONS

ERCP in octogenarians is safe and effective when compared to patients aged 60-79.

Endoscopic add-on stiffness probe for real-time soft surface characterisation in MIS

This paper explores a novel stiffness sensor which is mounted on the tip of a laparoscopic camera. The proposed device is able to compute stiffness when interacting with soft surfaces. The sensor can be used in Minimally Invasive Surgery, for instance, to localise tumor tissue which commonly has a higher stiffness when compared to healthy tissue. The purely mechanical sensor structure utilizes the functionality of an endoscopic camera to the maximum by visually analyzing the behavior of trackers within the field of view. Two pairs of spheres (used as easily identifiable features in the camera images) are connected to two springs with known but different spring constants. Four individual indenters attached to the spheres are used to palpate the surface. During palpation, the spheres move linearly towards the objective lens (i.e. the distance between lens and spheres is changing) resulting in variations of their diameters in the camera images. Relating the measured diameters to the different spring constants, a developed mathematical model is able to determine the surface stiffness in real-time. Tests were performed using a surgical endoscope to palpate silicon phantoms presenting different stiffness. Results show that the accuracy of the sensing system developed increases with the softness of the examined tissue.

High-performance aminated poly(phenylene sulfide)/ZnO nanocomposites for medical applications

An aminated poly(phenylene sulfide) derivative (PPS-NH2) has been melt-blended with different contents of ZnO nanoparticles, and the morphology, thermal, mechanical, tribological, antibacterial, and dielectric properties of the resulting nanocomposites have been investigated. The nanoparticles were dispersed within the matrix without the need for surfactants or coupling agents. A gradual rise in the crystallization temperature and the degree of crystallinity was found with increasing ZnO loading, confirming that the nanoparticles act as nucleating agents for PPS-NH2 crystallization. The nanoparticles reduced the water absorption and strongly increased the thermal stability of the matrix, leading to an extraordinary increase in the initial degradation temperature of 80 °C at 8.0 wt % nanoparticle content. The results showed that the stiffness, strength, toughness, glass transition, and heat distortion temperature were remarkably enhanced, whereas the coefficient of thermal expansion decreased upon addition of ZnO, ascribed to strong hydrogen bonding interactions between the amino groups of the matrix and the hydroxyl moieties of the nanoparticles. Moreover, the nanocomposites retained the tensile properties after being exposed to several cycles of steam sterilization. More importantly, an unprecedented drop in wear rate of nearly 100-fold was attained in the nanocomposite with the highest loading, demonstrating the suitability of these nanoparticles for providing wear resistance to the matrix. All the nanocomposites displayed low dielectric constant and dielectric loss, hence can be employed as insulating materials in electrosurgical applications. They also exhibited active inhibition against both Gram-positive and Gram-negative bacteria, which was gradually enhanced with increasing ZnO content. These nanocomposites are suitable as lightweight high-performance materials in the field of medicine and dentistry.

Liver deformation in an animal model due to pneumoperitoneum assessed by a vessel-based deformable registration

PURPOSE

Surgical navigation based on preoperative images partly overcomes some of the drawbacks of minimally invasive interventions - reduction of free sight, lack of dexterity and tactile feedback. The usefulness of preoperative images is limited in laparoscopic liver surgery, as the liver shifts due to respiration, induction of pneumoperitoneum and surgical manipulation. In this study, we evaluated the shift and deformation in an animal liver caused by respiration and pneumopertioneum using intraoperative cone beam CT.

MATERIAL AND METHODS

3D cone beam CT scans were acquired with arterial contrast. The centerlines of the segmented vessels were extracted from the images taken at different respiration and pressure settings. A non-rigid registration method was used to measure the shift and deformation. The mean Euclidean distance between the annotated landmarks was used for evaluation.

RESULTS

A shift and deformation of 44.6 mm on average was introduced due to the combined effect of respiration and pneumoperitoneum. On average 91% of the deformations caused by the respiration and pneumoperitoneum were recovered.

CONCLUSION

The results can contribute to the use of intraoperative imaging to correct for anatomic shift so that preoperative data can be used with greater confidence and accuracy during guidance of laparoscopic liver procedures.

Automated objective routine examination of optical quality of rigid endoscopes in a clinical setting

Rigid endoscopes degrade during clinical use due to sterilization, ionizing radiation and mechanical forces. Despite visual checks on functionality at the department of sterilization, surgeons are still confronted with suboptimal instruments as it is difficult to assess this degradation in an objective manner. To guarantee that endoscopes have sufficient optical quality for minimal invasive surgery, an experimental opto-electronic test bench has been developed in order to be used at the department of sterilization. Transmission of illumination fibres and lens contrast values are stored in a database to enable empirical criteria to reject endoscope for further clinical usage or to accept endoscopes after repair. Results of the test bench are given for an eight month period, where a trained operator performed 1599 measurements on 46 different types. Stability of the system, trends in quality of clinical endoscopes, and effect of repair or replacement were assessed. Although the period was too short to draw firm conclusions, a slow downwards trend in quality of clinically used endoscopes could be observed. Also, endoscopes generally improve in quality after repair or replacement, while endoscope replacement seems to slightly outperform endoscope repair. To optimize the measurement process, a new system is being developed requiring less user interaction and measuring more optical parameters of an endoscope. By commercializing this system, we hope that measurements at different hospitals will give improved insight which acceptance and rejection criteria to use and which factors (usage, cleaning protocol, and brands) determine the economic lifetime of endoscopes.

Self-folding devices and materials for biomedical applications

Because the native cellular environment is 3D, there is a need to extend planar, micro- and nanostructured biomedical devices to the third dimension. Self-folding methods can extend the precision of planar lithographic patterning into the third dimension and create reconfigurable structures that fold or unfold in response to specific environmental cues. Here, we review the use of hinge-based self-folding methods in the creation of functional 3D biomedical devices including precisely patterned nano- to centimeter scale polyhedral containers, scaffolds for cell culture and reconfigurable surgical tools such as grippers that respond autonomously to specific chemicals.

Postoperative care for the robotic surgery bowel resection patient

A new surgical method is available for colon and rectal surgery. Robotic surgery, using the daVinci Si HD Surgical System, offers surgical advances compared with the traditional open or laparoscopic surgical methods. The potential advantages of robotic technology continue to be explored and its most appropriate functions are yet to be determined. In clinical experience, the use of this surgical method has resulted in changes to postoperative nursing care management. This article describes changes in the management of postoperative patient care including fluid and electrolyte balance, and patient and staff education. Modifications were instituted in the clinical pathway to facilitate an accelerated standard of care. New discharge strategies were implemented to ensure ongoing fluid and electrolyte balance by the patient. A true team effort from a multitude of disciplines was required for the changes in patient care routine to be effective. Outcomes including length of stay and patient satisfaction are presented.

[True video-assisted thoracic surgery for early-stage non-small cell lung cancer]

从出现至今，微创手术对所有的外科分支学科均产生了巨大影响。电视辅助胸腔镜（VATS）肺叶切除术治疗早期非小细胞肺癌于20世纪90年代早期被首次报道，自此在许多医疗中心中逐渐普及。这项较新的技术的支持者列举了该技术在围手术期可能获得的许多有利结果，可能主要是因为该技术可减少手术创伤和应激反应。然而，由于仍缺乏有关长期生存和复发率的详实的临床数据，大部分胸心外科医生仍然持怀疑态度。

“全” VATS的定义目前仍不明确，之前的许多研究将其视为“小切口开胸肺叶切除术”，而非VATS肺叶切除术。在此，我们复习了有关全VATS肺叶切除术的文献，特别关注了直接对比VATS肺叶切除术和传统开胸肺叶切除术的比较研究。

Development and Experimental Evaluation of Oral Rehabilitation Robot that Provides Maxillofacial Massage to Patients with Oral Disorders

We have developed an oral-rehabilitation robot WAO-1 (Waseda Asahi Oral-rehabilitation robot No. 1) for use in cases of oral disorders such as temperomandibular joint (TMJ) disorder and dry mouth. WAO-1 is the first robot designed to provide massage to the facial tissues of a patient with oral disorders. This robot provides massage to the masseter and temporal muscles and to the parotid gland and duct with simple operation. It consists of two six-degree-of-freedom arms with plungers, a body with headrest, a control box, a PC, and an automatic massage trajectory generation system with virtual compliance control. Two evaluation experiments were performed to verify the effectiveness of the oral massages of WAO-1 compared with the massages given by doctors. In the experiments, the massage to the parotid gland and duct by WAO-1 increased the amount of saliva in the subjects, and the massage to the masseter muscle by WAO-1 increased facial skin temperature and width of the masseter muscle in the subjects. We consider that these results indicate that massage by WAO-1 can be effective for patients with oral disorders.

Proficiency-based virtual reality training significantly reduces the error rate for residents during their first 10 laparoscopic cholecystectomies

BACKGROUND

Virtual reality (VR) training has been shown previously to improve intraoperative performance during part of a laparoscopic cholecystectomy. The aim of this study was to assess the effect of proficiency-based VR training on the outcome of the first 10 entire cholecystectomies performed by novices.

METHODS

Thirteen laparoscopically inexperienced residents were randomized to either (1) VR training until a predefined expert level of performance was reached, or (2) the control group. Videotapes of each resident's first 10 procedures were reviewed independently in a blinded fashion and scored for predefined errors.

RESULTS

The VR-trained group consistently made significantly fewer errors (P = .0037). On the other hand, residents in the control group made, on average, 3 times as many errors and used 58% longer surgical time.

CONCLUSIONS

The results of this study show that training on the VR simulator to a level of proficiency significantly improves intraoperative performance during a resident's first 10 laparoscopic cholecystectomies.

Telerobotic surgery for right and sigmoid colectomies: 30 consecutive cases

BACKGROUND

This study aimed to evaluate the feasibility of using a robotic assistant for colon resections. This report describes the experience, advantages, and disadvantages of using the DaVinci system for a colectomy on the basis of 30 consecutive cases managed by a minimally invasive surgery fellowship-trained surgeon.

METHODS

Data were prospectively collected on 30 consecutive colectomies performed using the DaVinci system from September 2002 to March 2005.

RESULTS

A total of 13 sigmoid colectomies with splenic flexure mobilization and 17 right colectomies were performed for 14 men and 16 women. The preoperative diagnoses for the procedures were cancer (n = 5), diverticulitis (n = 8), polyps (n = 16), and carcinoid (n = 1). The right colectomies required 29.7 +/- 6.7 min (range, 22-44 min) for the port setup, 177.1 +/- 50.6 min (range, 103-306 min) for the robot, and 218.9 +/- 44.6 min (range, 167-340 min) for the total case. The length of stay was 5.2 +/- 5.8 days (range, 2-27 days). The robot portion was 80.9% of the total case time. The sigmoid colectomies required 30.1 +/- 9.6 min (range, 15-50 min) for the port setup, 103.2 +/- 29.4 min (range, 69-165 min) for the robot, and 225.2 +/- 37.1 min (range, 147-283 min) for the total case. The hospital length of stay was 6.0 +/- 7.3 days (range, 3-30 days). The robot portion was 45.8% of the total case time. Six complications occurred: left hip paresthesia, cecal injury, anastomotic leak, patient slipped from the operating table after the robotic portion of the case, transverse colon injury, and return of a patient to the office with urinary retention. Two sigmoid colectomies were converted to laparotomy. The specific advantages and disadvantages of using the DaVinci system for colectomies are discussed.

CONCLUSIONS

The 30 consecutive cases demonstrated the technical feasibility of using the DaVinci system for a colectomy. The longevity of the DaVinci system's use for colectomy will be determined by comparison of its cost and outcomes with those for conventional laparoscopic colectomy.