[Surgery for primary splenic tumors and metastases of the spleen]

The correct indications for surgical treatment of primary splenic tumors as well as metastases of the spleen are challenging due to the rarity of the various entities. Primary solid splenic tumors include benign lesions, such as hemangiomas, hamartomas and sclerosing angiomatous nodular transformation (SANT) of the spleen. In these cases, surgical treatment is indicated only in the case of inconclusive imaging and after careful consideration of the risk-benefit ratio, even in the case of pronounced symptoms. In contrast, primary angiosarcoma or undifferentiated pleomorphic sarcoma as highly malignant tumors represent an urgent indication for surgery. Although more frequent than primary splenic malignancies, secondary splenic tumors are also not that frequent. Solitary splenic metastases are rare; however, from an oncological point of view they can be treated by resection. In the case of oligometastasis with splenic involvement, splenectomy is used only as part of a palliative concept in cases of pronounced symptoms or in the context of cytoreductive surgery. In general, the laparoscopic approach is to be preferred when the operation is technically feasible as it is associated with fewer pulmonary and infectious complications and a shorter hospital stay. In addition, to reduce the risk of severe infections after splenectomy, the option of partial splenectomy should be considered, especially for benign lesions. A thorough informing of the patient regarding both intraoperative and perioperative risks as well as potential long-term sequelae, especially severe infectious diseases, is an essential component of informed consent before surgery.

Education Team Time Out in Oncologic Visceral Surgery Optimizes Surgical Resident Training and Team Communication-Results of a Prospective Trial

BACKGROUND

Surgical education is highly dependent on intraoperative communication. Trainers must know the trainee's training level to ensure high-quality surgical training. A systematic preoperative dialogue (Educational Team Time Out, ETO) was established to discuss the steps of each surgical procedure.

METHODS

Over 6 months, ETO was performed within a time limit of 3 minutes. Digital surveys on the utility of ETO and its impact on performance were conducted immediately after surgery and at the end of the study period among the staff of the participating disciplines (trainer, trainee, surgical nursing staff, anaesthesiologists, and medical students). The number of surgical substeps performed was recorded and compared with the equivalent period one year earlier.

RESULTS

ETO was performed in 64 of the 103 eligible operations (62%). Liver resection (n = 37) was the most frequent procedure, followed by left-sided colorectal surgery (n = 12), partial pancreaticoduodenectomy (n = 6), right-sided hemicolectomies (n = 5), and thyroidectomies (n = 4). Anaesthesiologists most frequently reported that ETO had a direct impact on their work during surgery (90.9%). The influence scores were 46.8% for trainees, 8.8% for trainers, 53.3% for surgical nursing staff and 66.6% for medical students. During the implementation of ETO, a trend towards more assisted substeps in oncologic visceral surgery was seen compared to the corresponding period one year earlier (51% vs.40%; p = 0.11).

CONCLUSION

ETO leads to improved intraoperative communication and more performed substeps during complex procedures, which increases motivation and practical training. This concept can easily be implemented in all surgical specialties to improve surgical education.

[Evidence, Availability and Future Visions in Simulation in General and Visceral Surgery]

Practice makes perfect - a saying that everyone has certainly heard. Surgeons of all levels of training can demonstrably practice to some extent on simulators. This training outside the operating theatre and independent of patients makes sense, both ethically and financially. Although the effectiveness of simulation in surgery has been proven several times, simulation training is not a mandatory part of surgical specialist training in Germany. Simulation covers a very wide range in terms of application, effort and costs. This review is intended to give an overview of the systems and their areas of application and the target group. The focus lies on the commonly available systems and possible advantages and disadvantages. Practical skills are in the foreground and all three pillars of general and visceral surgery - conventional techniques, laparoscopy and robotics - are taken into account. However, simulators alone do not achieve cost-benefit effectiveness. The full potential of such an investment can only be exploited with a site-specific, structured training concept in which simulation training according to the post-graduate year and appropriate allocation to surgeries in the operating room are closely interlinked. It should always be possible to train basic skills on site. The significant additional costs for complex simulation systems are possible, depending on the financial resources, or should be purchased in a network or for national courses. The techniques of immersive virtual reality in combination with artificial intelligence and deformation algorithms will certainly play a decisive role for the future of simulation, whereby the use of the available systems must be a primary goal. The integration of simulation into specialist training should be striven for, not least in order to justify the costs.

Real-Time Augmented Reality Annotation for Surgical Education During Laparoscopic Surgery: Results from a Single-Center Randomized Controlled Trial and Future Aspects

BACKGROUND

We developed an interactive augmented reality tool (HoloPointer) that enables real-time annotation on a laparoscopy monitor for intraoperative guidance. This application operates exclusively via verbal commands and head movements to ensure a sterile workflow.

STUDY DESIGN

Purpose of this randomized controlled clinical trial was to evaluate the integration of this new technology into the operating room. This prospective single-center study included 32 elective laparoscopic cholecystectomies (29 surgical teams, 15 trainees, 13 trainers). Primary objectives and assessment measures was the HoloPointer's influence on surgical performance (subjective assessment, global operative assessment of laparoscopic skills - GOALS, and Critical View of Safety -CVS). Secondary objectives and outcome variables were its influence on operation time, quality of assistance (5 point likert-scale), and user-friendliness (System Usability Scale - SUS, 0-100 points).

RESULTS

Gestural corrections were reduced by 59.4% (4.6 SD 8.1 vs. 1.9 SD 4.7; p > 0.05) and verbal corrections by 36.1% (17.8 SD 12.9 vs. 11.4 SD 8.1; p > 0.05). Subjective surgical performance could be improved by 84,6% of participants. No statistically significant differences were observed for objective parameters GOALS, CVS and operation time. In the SUS, the application achieved an average score of 72.5 SD 16.3 (good user-friendliness). Of the participants, 69.2% wanted to use the HoloPointer more frequently.

CONCLUSION

The majority of trainees had improved their surgical performance using the HoloPointer in elective laparoscopic cholecystectomies, and the rate of classic but potentially misleading corrections was noticeably reduced. The HoloPointer has the potential to improve education in minimally invasive surgery.

Leberchirurgie 4.0 - OP-Planung, Volumetrie, Navigation und Virtuelle Realität

Durch die Optimierung der konservativen Behandlung, die Verbesserung der bildgebenden Verfahren und die Weiterentwicklung der Operationstechniken haben sich das operative Spektrum sowie der Maßstab für die Resektabilität in Bezug auf die Leberchirurgie in den letzten Jahrzehnten deutlich verändert.

Dank zahlreicher technischer Entwicklungen, insbesondere der 3-dimensionalen Segmentierung, kann heutzutage die präoperative Planung und die Orientierung während der Operation selbst, vor allem bei komplexen Eingriffen, unter Berücksichtigung der patientenspezifischen Anatomie erleichtert werden.

Neue Technologien wie 3-D-Druck, virtuelle und augmentierte Realität bieten zusätzliche Darstellungsmöglichkeiten für die individuelle Anatomie. Verschiedene intraoperative Navigationsmöglichkeiten sollen die präoperative Planung im Operationssaal verfügbar machen, um so die Patientensicherheit zu erhöhen.

Dieser Übersichtsartikel soll einen Überblick über den gegenwärtigen Stand der verfügbaren Technologien sowie einen Ausblick in den Operationssaal der Zukunft geben.

Virtual reality and 3D printing improve preoperative visualization of 3D liver reconstructions-results from a preclinical comparison of presentation modalities and user's preference

Background

Preoperative three-dimensional (3D) reconstructions for liver surgery planning have been shown to be effective in reduction of blood loss and operation time. However, the role of the ‘presentation modality’ is not well investigated. We present the first study to compare 3D PDFs, 3D printed models (PR) and virtual reality (VR) 3D models with regard to anatomical orientation and personal preferences in a high volume liver surgery center.

Methods

Thirty participants, 10 medical students, 10 residents, 5 fellows and 5 hepatopancreatobiliary (HPB) experts, assigned the tumor-bearing segments of 20 different patient’s individual liver reconstructions. Liver models were presented in a random order in all modalities. Time needed to specify the tumor location was recorded. In addition, a score was calculated factoring in correct, wrong and missing segment assignments. Furthermore, standardized test/questionnaires for spatial thinking and seeing, vegetative side effects and usability were completed.

Results

Participants named significantly more correct segments in VR (P=0.040) or PR (P=0.036) compared to PDF. Tumor assignment was significantly shorter with 3D PR models compared to 3D PDF (P<0.001) or VR application (P<0.001). Regardless of the modality, HPB experts were significantly faster (24±8 vs. 35±11 sec; P=0.014) and more often correct (0.87±0.12 vs. 0.83±0.15; P<0.001) than medical students. Test results for spatial thinking and seeing had no influence on time but on correctness of tumor assignment. Regarding usability and user experience the VR application achieved the highest scores without causing significant vegetative symptoms and was also the most preferred method (n=22, 73.3%) because of the multiple functions like scaling and change of transparency. Ninety percent (n=27) stated that this application can positively influence the operation planning.

Conclusions

3D PR models and 3D VR models enable a better and partially faster anatomical orientation than reconstructions presented as 3D PDFs. User’s preferred the VR application over the PR models and PDF. A prospective trial is needed to evaluate the different presentation modalities regarding intra- and postoperative outcomes.

[Surgical Education in the Digital Age - Virtual Reality, Augmented Reality and Robotics in the Medical School]

Hintergrund Die digitale Transformation der Medizin verändert den Beruf des Arztes. Augmented und Virtual Reality (AR/VR) und die Robotik erfahren einen zunehmenden Einsatz in unterschiedlichen klinischen Kontexten und bedürfen einer begleitenden Aus- und Weiterbildung, die bereits im Medizinstudium beginnen muss. Hier besteht aktuell eine große Diskrepanz zwischen dem hohen Bedarf und der Anzahl an wissenschaftlich überprüften Konzepten. Ziel der vorliegenden Arbeit war die Konzeptionierung und strukturierte Evaluation eines neu entwickelten Lern-/Lehrkonzepts zur digitalen Transformation mit Fokus auf die chirurgische Lehre.

Methoden 35 Studierende haben in 3 Kursen des Blended-Learning-Curriculums „Medizin im digitalen Zeitalter“ teilgenommen. Das 4. Modul dieses Kurses thematisiert Virtual Reality, Augmented Reality und Robotik in der Chirurgie. Es gliedert sich in die folgenden Kursteile: (1) immersive Simulation einer laparoskopischen Cholezystektomie, (2) leberchirurgische Operationsplanung mittels AR/VR, (3) Basisfertigkeiten am VR-Simulator für robotische Chirurgie, (4) kollaborative OP Planung im virtuellen Raum und (5) Expertengespräch. Nach Abschluss des Gesamtcurriculums erfolgte eine qualitative und quantitative Evaluation des Kurskonzepts mittels semistrukturierter Interviews sowie anhand von standardisierten Prä-post-Evaluationsfragebögen.

Ergebnisse Im qualitativen Auswertungsverfahren der Interviews wurden 79 Textaussagen 4 Schwerpunktkategorien zugewiesen. Den größten Anteil (35%) nahmen hierbei Äußerungen zum „Expertengespräch“ ein, das von den Studierenden als elementarer Teil des Kurskonzepts gewertet wurde. Darüber hinaus empfanden die Studierenden den Kurs als horizonterweiterndes „Lernerlebnis“ (29% der Aussagen) mit einem hohen „Praxisbezug“ (27%). Die quantitative Studierendenevaluation zeigt eine positive Entwicklung für die Teilkompetenzen Wissen und Fertigkeiten sowie eine Tendenz zu einer positiven Haltung nach Kursabschluss.

Schlussfolgerung Die chirurgische Lehre ist zur Entwicklung digitaler Kompetenzen prädestiniert. Dabei muss die Geschwindigkeit des Veränderungsprozesses der digitalen Transformation im chirurgischen Fachgebiet beachtet und im curricularen Konzept verankert werden.

HoloPointer: a virtual augmented reality pointer for laparoscopic surgery training

PURPOSE

In laparoscopic surgery training, experts guide novice physicians to desired instrument positions or indicate relevant areas of interest. These instructions are usually given via verbal communication or using physical pointing devices. To facilitate a sterile work flow and to improve training, new guiding methods are needed. This work proposes to use optical see-through augmented reality to visualize an interactive virtual pointer on the laparoscopic.

METHODS

After an interdisciplinary development, the pointer's applicability and feasibility for training was evaluated and it was compared to a standard condition based on verbal and gestural communication only. In this study, ten surgical trainees were guided by an experienced trainer during cholecystectomies on a laparoscopic training simulator. All trainees completed a virtual cholecystectomy with and without the interactive virtual pointer in alternating order. Measures included procedure time, economy of movement and error rates.

RESULTS

Results of standardized variables revealed significantly improved economy of movement (p = 0.047) and error rates (p = 0.047), as well as an overall improved user performance (Total z-score; p = 0.031) in conditions using the proposed method.

CONCLUSION

The proposed HoloPointer is a feasible and applicable tool for laparoscopic surgery training. It improved objective performance metrics without prolongation of the task completion time in this pre-clinical setup.

Quality-based assessment of camera navigation skills for laparoscopic fundoplication

Laparoscopic fundoplication is considered the gold standard surgical procedure for the treatment of symptomatic hiatus hernia. Studies on surgical performance in minimally invasive hiatus hernia repair have neglected the role of the camera assistant so far. The current study was designed to assess the applicability of the structured assessment of laparoscopic assistance skills (SALAS) score to laparoscopic fundoplication as an advanced and commonly performed laparoscopic upper GI procedure. Randomly selected laparoscopic fundoplications (n = 20) at a single institute were evaluated. Four trained reviewers independently assigned SALAS scoring based on synchronized video and voice recordings. The SALAS score (5-25 points) consists of five key aspects of laparoscopic camera navigation as previously described. Experience in camera assistance was defined as at least 100 assistances in complex laparoscopic procedures. Nine different surgical teams, consisting of five surgical residents, three fellows, and two attending physicians, were included. Experienced and inexperienced camera assistants were equally distributed (10/10). Construct validity was proven with a significant discrimination between experienced and inexperienced camera assistants for all reviewers (P < 0.05). The intraclass correlation coefficient of 0.897 demonstrates the score's low interrater variability. The total operation time decreases with increasing SALAS score, not reaching statistical significance. The applied SALAS score proves effective by discriminating between experienced and inexperienced camera assistants in an upper GI surgical procedure. This study demonstrates the applicability of the SALAS score to a more advanced laparoscopic procedure such as fundoplication enabling future investigations on the influence of camera navigation on surgical performance and operative outcome.

Local, semi-automatic, three-dimensional liver reconstruction or external provider? An analysis of performance and time expense

PURPOSE

In hepatobiliary surgery, preoperative three-dimensional reconstruction based on CT or MRI can be provided externally or by local, semi-automatic software. We analyzed the time expense and quality of external versus local three-dimensional reconstructions.

METHODS

Three first-year residents reconstructed data from 20 patients with liver pathologies using a local, semi-automatic, server-based program. Initially, five randomly selected patient datasets were segmented, with the visualization of an established external company available for comparison at all times (learning phase). The other fifteen cases were compared with the external datasets after completing local reconstruction (control phase). Total time expense/case and for specific manual and semi-automated reconstruction steps were recorded. Segmentation quality was analyzed by testing the equivalence for liver and tumor volumes, portal vein sectors, and hepatic vein territories.

RESULTS

The median total reconstruction time was reduced from 2.5 h (learning phase) to 1.5 h (control phase) (- 42%; p < 0.001). Comparing the total and detailed liver volumes (sectors and territories) as well as the tumor volumes in the control phase equivalence was proven. In addition, a highly significant correlation between the external and local analysis was obtained over all analyzed segments with a very high ICC (median [IQR]: 0.98 [0.97; 0.99]; p < 0.01).

CONCLUSION

Local, semi-automatic reconstruction performed by inexperienced residents was feasible with an expert level time expense and the quality of the three-dimensional images was comparable with those from an external provider.

Rating of camera navigation skills in colorectal surgery

PURPOSE

In advanced minimally invasive surgery the laparoscopic camera navigation (LCN) quality can influence the flow of the operation. This study aimed to investigate the applicability of a scoring system for LCN (SALAS score) in colorectal surgery and whether an adequate scoring can be achieved using a specified sequence of the operation.

METHODS

The score was assessed by four blinded raters using synchronized video and voice recordings of 20 randomly selected laparoscopic colorectal surgeries (group A: assessment of the entire operation; group B: assessment of the 2nd and 3rd quartile). Experience in LCN was defined as at least 100 assistances in complex laparoscopic procedures.

RESULTS

The surgical teams consisted of three residents, three fellows, and two attendings forming 15 different teams. The ratio between experienced and inexperienced camera assistants was balanced (n = 11 vs. n = 9). Regarding the total SALAS score, the four raters discriminated between experienced and inexperienced camera assistants, regardless of their group assignment (group A, p < 0.05; group B, p < 0.05). The score's interrater variability and reliability were proven with an intraclass correlation coefficient of 0.88. No statistically relevant correlation was achieved between operation time and SALAS score.

CONCLUSION

This study presents the first intraoperative, objective, and structured assessment of LCN in colorectal surgery. We could demonstrate that the SALAS score is a reliable tool for the assessment of LCN even when only the middle part (50%) of the procedure is analyzed. Construct validity was proven by discriminating between experienced and inexperienced camera assistants.

Higher quality camera navigation improves the surgeon's performance: Evidence from a pre-clinical study

Introduction:

To objectively assess the quality of laparoscopic camera navigation (LCN), the structured assessment of LCN skills (SALAS) score was developed and validated for laparoscopic cholecystectomy. The aim of this pre-clinical study was to investigate the influence of LCN on surgical performance during virtual cholecystectomy (vCHE) using this score.

Methods:

A total of 84 medical students were included in this prospective study. Individual characteristics were assessed with questionnaires. Participants completed a structured 2-day training course on a validated virtual reality laparoscopic simulator. At the end of the course, all students took over LCN during vCHE, all performed by the same surgeon. The numbers of errors regarding centering, horizon adjustment and instrument visualisation as well as manual and verbal corrections by the surgeon were recorded to calculate the SALAS score (range 5–25) to investigate the influence of LCN on surgical performance. The study population was divided by the recorded SALAS score into low and medium performers (Group A; 1^st–3^rd quartile; n = 60) and high performers (Group B, 4^th quartile, n = 21).

Results:

The SALAS score of the camera assistant correlates positively with the surgeon's overall performance in vCHE (P < 0.001), and the surgeon's virtual laparoscopic performance was significantly better in Group B (P < 0.001). Moreover, a significantly shorter operation time during vCHE was shown for Group B (Median (IQR); Group A: 508 s [429 s; 601 s]; Group B: 422 s [365 s; 493 s]; P = 0.001). Frequent gaming and a higher self-confidence to assist during a basic laparoscopic procedure were associated with a higher SALAS score (P = 0.013).

Conclusion:

In this pre-clinical setting, the surgeon's virtual performance is significantly influenced by the LCN quality. LCN by high performers resulted in a shorter operation time and a lower error rate.

[Right Trisectionectomy and Hilar Resection with Resection and Reconstruction of the Portal Vein Bifurcation and Left Hepatic Vein in Cholangiocellular Carcinoma]

Complete surgical resection of intrahepatic cholangiocellular carcinoma is considered the primary option for curative treatment. With tumour extension, resection and reconstruction of vascular structures can be necessary. Three dimensional planning of surgical resection can be useful in selected cases. The current video shows an extended right sided hemihepatectomy with hilar resection and reconstruction of the left portal vein and one of two branches of the left hepatic vein in a patient with intrahepatic cholangiocarcinoma.