Perioperative pain management with regional analgesia techniques for visceral cancer surgery: A systematic review and meta-analysis

STUDY OBJECTIVE

Regional analgesia following visceral cancer surgery might provide an advantage but evidence for best treatment options related to risk-benefit is unclear.

DESIGN

Systematic review of randomized controlled trials (RCT) with meta-analysis and GRADE assessment.

SETTING

Postoperative pain treatment.

PATIENTS

Adult patients undergoing visceral cancer surgery.

INTERVENTIONS

Any kind of peripheral (PRA) or epidural analgesia (EA) with/without systemic analgesia (SA) was compared to SA with or without placebo treatment or any other regional anaesthetic techniques.

MEASUREMENTS

Primary outcome measures were postoperative acute pain intensity at rest and during activity 24 h after surgery, the number of patients with block-related adverse events and postoperative paralytic ileus.

MAIN RESULTS

59 RCTs (4345 participants) were included. EA may reduce pain intensity at rest (mean difference (MD) -1.05; 95% confidence interval (CI): -1.35 to -0.75, low certainty evidence) and during activity 24 h after surgery (MD -1.83; 95% CI: -2.34 to -1.33, very low certainty evidence). PRA likely results in little difference in pain intensity at rest (MD -0.75; 95% CI: -1.20 to -0.31, moderate certainty evidence) and pain during activity (MD -0.93; 95% CI: -1.34 to -0.53, moderate certainty evidence) 24 h after surgery compared to SA. There may be no difference in block-related adverse events (very low certainty evidence) and development of paralytic ileus (very low certainty of evidence) between EA, respectively PRA and SA.

CONCLUSIONS

Following visceral cancer surgery EA may reduce pain intensity. In contrast, PRA had only limited effects on pain intensity at rest and during activity. However, we are uncertain regarding the effect of both techniques on block-related adverse events and paralytic ileus. Further research is required focusing on regional analgesia techniques especially following laparoscopic visceral cancer surgery.

ESPEN Guidelines on Clinical nutrition in surgery - Special issues to be revisited

The ESPEN Guidelines on Clinical nutrition in Surgery from 2017 has been also available as practical guideline with algorithms since 2021 (www.espen.org). An update will be perfomed in the near future. This review focuses on recent data with regard to special issues and topics to be revisited in the guidelines: These are nutritional assessment, sarcopenic obesity, prehabilitation, oral/enteral immunonutrition, postoperative oral supplementation in hospital and after discharge.

[The new continuing education regulations-A challenge for visceral surgery : Results of a survey among DGAV members and solution strategies of the Young Surgeons]

BACKGROUND

The new competency-based further training regulations (nWBO) for surgical training have been adopted by all German state medical associations.

METHODS

From May to June 2023 the Young Surgeons' Working Group (CAJC) conducted an anonymous online survey among the 5896 members of the German Society for General and Visceral Surgery (DGAV).

OBJECTIVE

The survey aimed to assess expectations regarding the nWBO and to develop strategies for enhancing surgical training.

RESULTS

With 488 participants (response rate 8.3%) the study is representative. The respondents consisted of 107 continuing education assistants (WBA 21.9%), 69 specialist physicians, and 188 senior physicians (specialist physicians 14.1% and senior physicians 38.5%), as well as 107 chief physicians (21.9%). The majority worked in regular care providers (44%), followed by maximum care providers (26.8%) and university clinics (20.1%). Only 22% considered the required operative spectrum of the new medical specialist training regulations (nWBO) to be realistic. Half of the respondents believed that full training in their clinic according to the new catalog will no longer be possible and 54.6% considered achieving the target numbers in 6 years to be impossible or state that they can no longer train the same number of continuing education assistants (WBAs) in the same time frame. Endoscopy (17.1-18.8%), fundoplication (15.4-17.7%) and head and neck procedures (12.1-17.1%) were consistently mentioned as bottlenecks across all levels of care. Rotations for balance were reported to be already established or not necessary in 64.7%. In 48% it was stated that the department had established the partial steps concept. The importance of a structured training concept was considered important by 85% of WBAs, compared to 53.3% of chief physicians (CÄ). If a structured training concept was present in the department, the achievability of the target numbers was significantly assessed more positively in the univariate analysis. In the multivariate analysis, male gender and the status of "habilitated/professor" were independent factors for a more positive assessment of the nWBO. Objective certification of training was considered important by 51.5%.

CONCLUSION

Concerns surround the nWBO and the sentiment is pessimistic. Additional requirements and hospital reforms could exacerbate the situation. Collaboration and rotations are crucial but still insufficiently implemented. Quality-oriented certification could enhance the quality of training.

[Safety of patient care on an interprofessional training ward in visceral surgery]

BACKGROUND

Interprofessional training wards (ITW) are increasingly being integrated into teaching and training concepts in visceral surgery clinics.

OBJECTIVE

How safe is patient care on an ITW in visceral surgery?

MATERIAL AND METHODS

Data collection took place from November 2021 to December 2022. In this nonrandomized prospective evaluation study the frequency and severity of adverse events (AE) in 3 groups of 100 patients each in a tertiary referral center hospital for visceral surgery were investigated. The groups consisted of patients on the ITW and on the conventional ward before and after implementation of the ITW. The Global Trigger Tool (GTT) was used to search for AE. Simultaneously, a survey of the treatment was conducted according to the Picker method to measure patient reported outcome.

RESULTS

Baseline characteristics and clinical outcome parameters of the patients in the three groups were comparable. The GTT analysis found 74 nonpreventable and 5 preventable AE in 63 (21%) of the patients and 12 AE occurred before the hospital stay. During the hospital stay 50 AE occurred in the operating theater and 17 on the conventional ward. None of the five preventable AE (in 1.7% of the patients) was caused by the treatment on the ITW. Patients rated the safety on the ITW better than in 90% of the hospitals included in the Picker benchmark cohort and as good as on the normal ward.

CONCLUSION

The GTT-based data as well as from the patients' point of view show that patient care on a carefully implemented ITW in visceral surgery is safe.

Cost saving in implementing ERAS protocol in emergency abdominal surgery

INTRODUCTION

ERAS (Enhanced Recovery After Surgery) protocol is now proposed as the standard of care in elective major abdominal surgery. Implementation of the ERAS protocol in emergency setting has been proposed but his economic impact has not been investigated. Aim of this study was to evaluate the cost saving of implementing ERAS in abdominal emergency surgery in a single institution.

METHODS

A group of 80 consecutive patients treated by ERAS protocol for gastrointestinal emergency surgery in 2021 was compared with an analogue group of 75 consecutive patients treated by the same surgery the year before implementation of ERAS protocol. Adhesion to postoperative items, length of stay, morbidity and mortality were recorded. Cost saving analysis was performed.

RESULTS

50% Adhesion to postoperative items was reached on day 2 in the ERAS group in mean. Laparoscopic approach was 40 vs 12% in ERAS and control group respectively (p ,002). Length of stay was shorter in ERAS group by 3 days (9 vs 12 days p ,002). Morbidity and mortality rate were similar in both groups. The ERAS group had a mean cost saving of 1022,78 € per patient.

CONCLUSIONS

ERAS protocol implementation in the abdominal emergency setting is cost effective resulting in a significant shorter length of stay and cost saving per patient.

[Organization of continuing education at a university hospital]

Continuing education at German university hospitals is individually organized within the framework of the continuing education regulations. In the personal organization (University Medical Center Schleswig-Holstein, Campus Luebeck) three sections (common trunk, medical specialist for visceral surgery and additional qualification in special visceral surgery) and two lines (clinical line and academic clinical line) are differentiated. The whole training is flanked by the mediation of technical competence even outside the operating room (Lübeck toolbox, RoSTraC curriculum, suture courses etc.). Future concepts for continuing education must take the healthcare structure in hospitals, the increasing specialization and the increasing technical complexity into account.

Oncological recurrence following pathological complete response after neoadjuvant treatment in patients with esophageal cancer - a retrospective cohort study

BACKGROUND

To evaluate recurrence in patients with post-neoadjuvant pathological complete response (pCR) and in patients with complete response of primary tumor but persisting lymphatic spread of disease (non-pCR, ypT0ypN +) of esophageal cancer.

METHODS

Seventy-five patients (63 pCR, 12 non-pCR) were analyzed retrospectively. Pattern and incidence of local and distant recurrence as well as the impact on overall (OS) and disease-free survival (DFS) were evaluated. The efficacy of neoadjuvant chemotherapy according to FLOT protocol was compared to neoadjuvant chemoradiation according to CROSS protocol.

RESULTS

In the pCR group, isolated local recurrence was diagnosed in 3%, while no isolated local recurrence was observed in the non-pCR group due to the high incidence of distant recurrence. Distant recurrence was most common in both cohorts (isolated distant recurrence: pCR group 10% to non-pCR group 55%; simultaneous distant and local recurrence: pCR group 3% to non-pCR group 18%). Median time to distant recurrence was 5.5 months, and median time to local recurrence was 8.0 months. Cumulative incidence of distant recurrence (with and without simultaneous local recurrence) was 16% (± 6%) in pCR patients and 79% (± 13%) in non-pCR patients (hazard ratio (HR) 0.123) estimated by Kaplan-Meier method. OS (HR 0.231) and DFS (HR 0.226) were significantly improved in patients with pCR compared to patients with non-pCR. Advantages for FLOT protocol compared to CROSS protocol, especially with regard to distant control of disease (HR 0.278), were observed (OS (HR 0.361), DFS (HR 0.226)).

CONCLUSION

Distant recurrence is the predominant site of treatment failure in patients with pCR and non-pCR grade 1a regression, whereby recurrence rates are much higher in patients with non-pCR.

Proximal gastrectomy and double-tract reconstruction vs total gastrectomy in gastric and gastro-esophageal junction cancer patients - a systematic review and meta-analysis protocol (PROSPERO registration number: CRD42021291500)

BACKGROUND

In Germany and Western Europe, gastroesophageal junction cancer (AEG) and proximal gastric cancer are currently treated with (transhiatal-extended) total gastrectomy (TG) according to the latest treatment guidelines. TG leads to a severe and long-lasting impairment of postoperative health-related quality of life (HRQoL) of the treated patients. Recent studies have suggested that HRQoL of these patients could be improved by proximal gastrectomy with double-tract reconstruction (PG-DTR) without compromising oncologic safety. Our aim is therefore to conduct a randomized controlled non-inferiority trial comparing PG-DTR with TG in AEG II/III and gastric cancer patients with overall survival as primary endpoint and HRQoL as key secondary endpoint.

METHODS

This protocol is written with reference to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P 2015) statement. We will conduct searches in the electronic databases MEDLINE, Web of Science Core Collection, ScienceDirect, and Cochrane Library. We will also check references of relevant studies and perform a cited reference research. Titles and abstracts of the records identified by the searches will be screened, and full texts of all potentially relevant articles will be obtained. We will consider randomized trials and non-randomized studies. The selection of studies, data extraction, and assessment of risk of bias of the included studies will be conducted independently by two reviewers. Meta-analysis will be performed using RevMan 5.4 (Review Manager (RevMan) Version 5.4, The Cochrane Collaboration).

DISCUSSION

This systematic review will identify the current study pool concerning the comparison of TG and PG-DTR and help to finally refine the research questions and to allow an evidence-based trial design of the planned multicenter randomized-controlled trial.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review. Study findings will be shared by publication in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021291500.

Rectal colonization is predictive for surgical site infections with multidrug-resistant bacteria in abdominal surgery

PURPOSE

Superficial surgical site infections (SSI) are a common complication after abdominal surgery. Additionally, multidrug-resistant organisms (MDRO) have shown an increasing spread in recent years with a growing importance for health care. As there is varying evidence on the importance of MDRO in different surgical fields and countries as causative agents of SSI, we report our findings of MDRO-caused SSI.

METHODS

We assembled an institutional wound register spanning the years 2015-2018 including all patients with abdominal surgery and SSI only, including demographics, procedure-related data, microbiological data from screenings, and body fluid samples. The cohort was examined for the frequency of different MDRO in screenings, body fluids, and wound swabs and assessed for risk factors for MDRO-positive SSI.

RESULTS

A total of 138 out of 494 patients in the register were positive for MDRO, and of those, 61 had an MDRO isolated from their wound, mainly multidrug-resistant Enterobacterales (58.1%) followed by vancomycin-resistant Enterococcus spp. (19.7%). As 73.2% of all MDRO-carrying patients had positive rectal swabs, rectal colonization could be identified as the main risk factor for an SSI caused by a MDRO with an odds ratio (OR) of 4.407 (95% CI 1.782-10.896, p = 0.001). Secondly, a postoperative ICU stay was also associated with an MDRO-positive SSI (OR 3.73; 95% CI 1.397-9.982; p = 0.009).

CONCLUSION

The rectal colonization status with MDRO should be taken into account in abdominal surgery regarding SSI prevention strategies. Trial registration Retrospectively registered in the German register for clinical trials (DRKS) 19th December 2019, registration number DRKS00019058.

[Expected effects of the new continuing education regulations in general and visceral surgery : Survey among Bavarian surgeons and residents]

INTRODUCTION

The new competency-based continuing education regulations for surgical training (WBO) came into effect in Bavaria in August 2022.

METHODS

From May to July 2022, we conducted an anonymized online survey among Bavarian general and visceral surgeons and surgical residents (ÄiW). The aim was to survey expectations of the effects of the new WBO.

RESULTS

The response rate was 35%. In total data could be collected from 80 persons, 36 ÄiW (45%), 30 specialists and senior physicians (37.5%) and 14 chief physicians (17.5%). The majority of respondents worked at a university hospital (38.8%) or a regular provider (35%). A strengthening of the competence to act through implementation of the new WBO is seen by 41.3% and 55.7% see independent operating under partial supervision by the instructor as a goal. Of the respondents 50% see the required case numbers as not achievable and 55.1% deny reaching them in the expected period of 6 years. About 60% do not expect to be able to train the same number of ÄiWs in the same amount of time. Almost 75% of the respondents state that from their point of view, a good continuing education with the achievement of a solid competence to act would not work without overtime hours. About 44% of the respondents expect that a full surgical training would continue to be possible at their institution.

CONCLUSION

Both among the instructors and among the trainees there is a tendency to fear that realistic training, in particular the achievement of the guideline figures, will no longer be possible in the usual further training time. This necessitates the consistent implementation of structured continuing education with a high degree of transparency in training.

[Intraoperative fluorescence-guided perfusion assessment using indocyanine green-Increased safety in gastrointestinal anastomoses?]

Insufficiency of gastrointestinal anastomoses represents a relevant risk of morbidity and mortality for affected patients. The perfusion quality of the ends of the intestine is the decisive parameter for ensuring sufficient healing of an anastomosis. Intraoperative fluorescence-guided perfusion assessment with indocyanine green is increasingly being used in modern visceral surgery to evaluate tissue perfusion prior to the fashioning of gastrointestinal anastomoses. This technique provides the possibility to distinguish between adequately and inadequately perfused tissue in order to place the anastomosis in the region with the best possible perfusion. Thus, surgeons have a measuring instrument that enables an objective assessment of the perfusion quality of the tissue to be undertaken in addition to a purely subjective macroscopic visual assessment, in order to achieve a better functional result for the patients. Currently, however, the value of this technique has not yet been conclusively clarified. The aim of this review article is to characterize the benefits of intraoperative fluorescence-guided perfusion assessment and to classify it with respect to its significance for routine clinical practice.

[Artificial intelligence and hyperspectral imaging for image-guided assistance in minimally invasive surgery]

BACKGROUND

Intraoperative imaging assists surgeons during minimally invasive procedures. Hyperspectral imaging (HSI) is a noninvasive and noncontact optical technique with great diagnostic potential in medicine. The combination with artificial intelligence (AI) approaches to analyze HSI data is called intelligent HSI in this article.

OBJECTIVE

What are the medical applications and advantages of intelligent HSI for minimally invasive visceral surgery?

MATERIAL AND METHODS

Within various clinical studies HSI data from multiple in vivo tissue types and oncological resections were acquired using an HSI camera system. Different AI algorithms were evaluated for detection and discrimination of organs, risk structures and tumors.

RESULTS

In an experimental animal study 20 different organs could be differentiated with high precision (> 95%) using AI. In vivo, the parathyroid glands could be discriminated from surrounding tissue with an F1 score of 47% and sensitivity of 75%, and the bile duct with an F1 score of 79% and sensitivity of 90%. Furthermore, ex vivo tumor tissue could be successfully detected with an area under the receiver operating characteristic (ROC) curve (AUC) larger than 0.91.

DISCUSSION

This study demonstrates that intelligent HSI can automatically and accurately detect different tissue types. Despite great progress in the last decade intelligent HSI still has limitations. Thus, accurate AI algorithms that are easier to understand for the user and an extensive standardized and continuously growing database are needed. Further clinical studies should support the various medical applications and lead to the adoption of intelligent HSI in the clinical routine practice.

[Minimum case volumes from the perspective of specialists in smaller facilities]

BACKGROUND

The introduction of compulsory minimum hospital volumes for the majority of operations in visceral surgery according to the current state of discussions will lead to a profound change in the provision of surgical treatment in Germany.

METHODS

This article gives a narrative review of the literature and evidence as well as current regulations.

RESULTS

In Germany gastric interventions for cancer are associated with the highest perioperative risk in visceral surgery with a mortality of 11.7%. The highest number of annual fatalities by far are reported after colorectal resections (n = 6186). The already decided and planned minimum volumes (esophagus and pancreas) not only do not address these urgent quality issues but even lead to a paradoxical decentralization effect for colorectal and gastric interventions, by weakening medium size and also large hospitals. The minimum volumes that are planned to be subsequently introduced for liver resection, gastric cancer surgery, colorectal cancer surgery, resection for diverticulitis and thyroid resection will not enable a persistence of visceral surgery as a coherent specialty in the remaining clinical landscape. As an alternative, a three-stage model is suggested that defines groups of operations with similar complexity with a common compulsory minimum volume. These groups together with the respective requirements in infrastructure, make up a certain level of care.

CONCLUSION

The model suggested will induce a meaningful differentiation of surgical treatment providers that will adequately address surgical quality as well as the preservation of visceral surgery as a coherent specialty.

Clinical characteristics and outcome of patients with acute mesenteric ischemia: a retrospective cohort analysis

BACKGROUND

Acute mesenteric ischemia (AMI) is an uncommon, but life-threatening clinical entity due to late diagnosis resulting in irreversible ischemic bowel necrosis. The most common causes of AMI are the embolic occlusion and the acute thrombosis of the mesenteric circulation. Typical treatment is composed of an early revascularization of the mesenteric circulation followed by abdominal surgery for resection of nonviable intestine and restoration of the intestinal continuity, but the mortality rates remain high.

METHODS

A retrospective cohort analysis was conducted, aiming to evaluate clinical characteristics, performed surgical procedures and outcomes of patients with acute mesenteric ischemia who underwent emergency abdominal surgery at a high volume surgical center in Germany.

RESULTS

Overall, 53 patients were identified with the intraoperatively proven diagnosis of AMI. Overall hospital mortality was with 62% comparable to the literature. Nineteen patients presented with an intraoperatively verified complete and non-reversible intestinal infarction without any angiographic or surgical option for a revascularization of the mesenteric circulation or an option for intestinal resection. From the rest of the patients, 14 underwent intestinal resection of the ischemic area without restoration of intestinal continuity; the other 20 underwent resection with a primary anastomosis to restore intestinal continuity. The mortality rate of these patients with curative-intended surgery remained high (41% of patients died). Pre- and postoperative hyperlactatemia were associated with lower survival of these patients.

CONCLUSION

AMI remains a life-threatening abdominal emergency. Therapeutic approaches are highly depended on acting surgeon's decision, being affected by subjectively rated bowel viability and physical condition of the affected patient. Only selected patients with good bowel viability appear to be suitable for receiving primary anastomosis. The results clearly indicate the need for further research to develop therapeutic approaches for a better management of AMI and to improve outcome of affected patients.

The impact of surgical site infection-a cost analysis

Purpose

Surgical site infection (SSI) occurs in up to 25% of patients after elective laparotomy. We aimed to determine the effect of SSI on healthcare costs and patients’ quality of life.

Methods

In this post hoc analysis based on the RECIPE trial, we studied a 30-day postoperative outcome of SSI in a single-center, prospective randomized controlled trial comparing subcutaneous wound irrigation with 0.04% polyhexanide to 0.9% saline after elective laparotomy. Total medical costs were analyzed accurately per patient with the tool of our corporate controlling team which is based on diagnosis-related groups in Germany.

Results

Between November 2015 and May 2018, 456 patients were recruited. The overall rate of SSI was 28.2%. Overall costs of inpatient treatment were higher in the group with SSI: median 16.685 €; 19.703 USD (IQR 21.638 €; 25.552 USD) vs. median 11.235 €; 13.276 USD (IQR 11.564 €; 13.656 USD); p < 0.001. There was a difference in surgery costs (median 6.664 €; 7.870 USD with SSI vs. median 5.040 €; 5.952 USD without SSI; p = 0.001) and costs on the surgical ward (median 8.404 €; 9.924 USD with SSI vs. median 4.690 €; 5.538 USD without SSI; p < 0.001). Patients with SSI were less satisfied with the cosmetic result (4.3% vs. 16.2%; p < 0.001). Overall costs for patients who were irrigated with saline were median 12.056 €; 14.237 USD vs. median 12.793 €; 15.107 USD in the polyhexanide group (p = 0.52).

Conclusion

SSI after elective laparotomy increased hospital costs substantially. This is an additional reason why the prevention of SSI is important. Overall costs for intraoperative wound irrigation with saline were comparable with polyhexanide.

[Perioperative fluid management in major abdominal surgery]

Intravascular fluid administration belongs to the cornerstones of perioperative treatment with a substantial impact on surgical outcome especially with respect to major abdominal surgery. By avoidance of hypovolemia and hypervolemia, adequate perioperative fluid management significantly contributes to the reduction of insufficient tissue perfusion as a determinant of postoperative morbidity and mortality. The effective use of intravascular fluids requires detailed knowledge of the substances as well as measures to guide fluid therapy. Fluid management already starts preoperatively and should be continued in the postoperative setting (recovery room, peripheral ward) considering a patient-adjusted and surgery-adjusted hemodynamic monitoring. Communication between all team members participating in perioperative care is essential to optimize fluid management.

[Intraoperative rapid frozen section-when meaningful, when necessary?]

Intraoperative frozen sections can significantly improve the results of numerous visceral surgical operations. For this a close cooperation between surgery and pathology is a basic prerequisite. The main indications are the diagnostics of unclear intraoperative findings and the assessment of resection margins. Just as in any other procedure, there are also limiting factors to be considered in frozen section examinations.

[How severe is the effect of the coronavirus pandemic on the department of surgery of a university hospital? : An analysis of the first 7 weeks]

Hintergrund

Die Corona-Pandemie stellt Krankenhäuser vor enorme finanzielle Herausforderungen. Am Beispiel einer Klinik für Viszeral‑, Transplantations‑, Thorax- und Gefäßchirurgie (VTTG) soll die Leistungsentwicklung in der stationären Versorgung der ersten 7 Wochen nach Beginn der gesetzgeberisch angeordneten Leistungsreduktion im Vorjahresvergleich sowie eine Bewertung der gesetzgeberisch festgelegten Kompensationsmaßnahmen bewertet werden.

Methodik

Anhand der Leistungszahlen wird ein Vergleich des Zeitraumes vom 16.03. bis 03.05.2019 mit demselben Zeitraum 2020 durchgeführt. Veränderungen von Fallzahl, Case-Mix, Case-Mix-Index und Day-Mix-Index sowie der Belegungstage werden erfasst. Diesen Veränderungen werden die monetären Maßnahmen aus dem COVID-19-Krankenhausentlastungsgesetz gegenübergestellt und deren Auskömmlichkeit bewertet.

Ergebnisse

Im Vergleich zum Vorjahr kommt es im Beobachtungszeitraum zu einem Rückgang der stationären Aufnahmen von 120 Patienten. Demzufolge waren ein Rückgang des Case-Mix um 370 Punkte und der Belegung um 1433 Tage zu verzeichnen. Über die gesamte VTTG ergibt sich ein Erlösrückgang von ca. 0,8 Mio. €, der durch die Leerbettenpauschale vollständig kompensiert wird. Die einzelnen Bereiche zeigen in Bezug auf die Kompensationsmechanismen ein heterogenes Bild mit einer Unterdeckung elektiver Bereiche bis zu 128.163 € in Bezug auf die stationären Leistungen für 7 Wochen.

Diskussion

Die Maßnahmen des Gesetzgebers stellen eine wichtige Stütze zur wirtschaftlichen Absicherung deutscher Krankenhäuser dar. Die fehlende Differenzierung der Maßnahmen nach Fachrichtung führt für die VTTG zu einem heterogenen Bild in der Auskömmlichkeit und muss als Warnsignal insbesondere für elektive chirurgische Leistungserbringer gesehen werden.

Acoustic signal analysis of instrument-tissue interaction for minimally invasive interventions

Purpose

Minimally invasive surgery (MIS) has become the standard for many surgical procedures as it minimizes trauma, reduces infection rates and shortens hospitalization. However, the manipulation of objects in the surgical workspace can be difficult due to the unintuitive handling of instruments and limited range of motion. Apart from the advantages of robot-assisted systems such as augmented view or improved dexterity, both robotic and MIS techniques introduce drawbacks such as limited haptic perception and their major reliance on visual perception.

Methods

In order to address the above-mentioned limitations, a perception study was conducted to investigate whether the transmission of intra-abdominal acoustic signals can potentially improve the perception during MIS. To investigate whether these acoustic signals can be used as a basis for further automated analysis, a large audio data set capturing the application of electrosurgery on different types of porcine tissue was acquired. A sliding window technique was applied to compute log-mel-spectrograms, which were fed to a pre-trained convolutional neural network for feature extraction. A fully connected layer was trained on the intermediate feature representation to classify instrument–tissue interaction.

Results

The perception study revealed that acoustic feedback has potential to improve the perception during MIS and to serve as a basis for further automated analysis. The proposed classification pipeline yielded excellent performance for four types of instrument–tissue interaction (muscle, fascia, liver and fatty tissue) and achieved top-1 accuracies of up to 89.9%. Moreover, our model is able to distinguish electrosurgical operation modes with an overall classification accuracy of 86.40%.

Conclusion

Our proof-of-principle indicates great application potential for guidance systems in MIS, such as controlled tissue resection. Supported by a pilot perception study with surgeons, we believe that utilizing audio signals as an additional information channel has great potential to improve the surgical performance and to partly compensate the loss of haptic feedback.

[Possibilities and perspectives of hyperspectral imaging in visceral surgery]

HyperSpectral Imaging (HSI) technology enables quantitative tissue analyses beyond the limitations of the human eye. Thus, it serves as a new diagnostic tool for optical properties of diverse tissues. In contrast to other intraoperative imaging methods, HSI is contactless, noninvasive, and the administration of a contrast medium is not necessary. The duration of measurements takes only a few seconds and the surgical procedure is only marginally disturbed. Preliminary HSI applications in visceral surgery are promising with the potential of optimized outcomes. Current concepts, possibilities and new perspectives regarding HSI technology together with its limitations are discussed in this article.

Analysis of malpractice claims: The Franco-Belgian "Cœlio Club" experience

Malpractice claims are a regularly increasing concern in gastrointestinal surgery. The goal of this study was to compare the current status of claims in two different French-speaking communities by a retrospective descriptive study of surgeons' experiences, from the beginning of their practice up until December 31 2014. Data included the number, the reasons, and the results of medicolegal claims and their jurisdictions. Forty-three surgeons participated in this study. Two hundred medicolegal claims were analyzed. The mean number was 5.8 per surgeon. Bariatric surgery, colorectal surgery and parietal surgery were the most exposed. Forty-six (23%) faults were noted, while no fault was pronounced in 139 (69.5%) cases. The main reasons for lodging complaints were nosocomial infections, anastomotic leaks, poor postoperative care, hollow organ perforation, peripheral neurologic complication, and insufficient preoperative information. Forty-four percent of the complaints were analyzed by the conciliation and compensation commissions and 43.5% by the High Court. In the French-speaking group, there were 13 complaints, two of which gave rise to compensation. French surgeons are highly exposed to complaints: in French law, clumsiness or technical maladdress is considered as a fault. The patient should be informed preoperatively of all possible severe risks of a medical procedure. In Belgium, complications are exceptional and are considered random therapeutic events. Adhering to the recommendations emanating from the French High Authority of Health and Learned Societies as well as accreditation issued by the same High Authority should allow to decrease the number of undesirable events related to care and malpractice.

[Special situations of preconditioning and prehabilitation in oncological visceral surgery]

BACKGROUND

Prehabilitation prior to complex visceral oncological surgery is playing an increasingly important role.

OBJECTIVE

The aim of this review article is to present special situations of preconditioning in visceral oncological patient cohorts. The following conditions were defined as special situations with subsequently increased risk profile: cardiopulmonary comorbidities, geriatric patients, neoadjuvant therapy and simultaneous fatigue.

MATERIAL AND METHODS

A selective literature review based on a search in the electronic databases MEDLINE, PubMed, Cochrane Library and the International Standard Randomization Controlled Trial Number (ISRCTN) was performed.

RESULTS

The identification of high-risk patients is an essential part of the preoperative evaluation conducted by the anesthesiologist prior to surgery. The cardiovascular and the pulmonary risk profile are determined by means of prediction indices evaluating patient-specific and surgery-related risk factors. The increased use of new oral anticoagulants and dual platelet aggregation inhibition requires individualized treatment strategies. Numerous studies have shown clinically relevant effects of exercise therapy interventions throughout all phases of oncological treatment. In addition to positive effects on therapy-associated side effects, sport can also counteract the effects of sedentary behavior in cancer patients and improve the health-related quality of life. The effectiveness of sport and exercise therapies as well as psychological interventions in oncological patients with fatigue (CRF) is broad, with important components being motivation and compliance.

DISCUSSION

In high-risk patients an interdisciplinary approach to planning and conduction of prehabilitation is essential for the early detection and optimization of perioperative risk factors and potential complications. The aim is faster recovery, reduced morbidity and mortality and the possibility to improve long-term survival and quality of life.

Tissue classification of oncologic esophageal resectates based on hyperspectral data

PURPOSE

Esophageal carcinoma is the eighth most common cancer worldwide. Esophageal resection with gastric pull-up is a potentially curative therapeutic option. After this procedure, the specimen is examined by the pathologist to confirm complete removal of the cancer. An intraoperative analysis of the resectate would be less time-consuming and therefore improve patient safety.

METHODS

Hyperspectral imaging (HSI) is a relatively new modality, which has shown promising results for the detection of tumors. Automatic approaches could support the surgeon in the visualization of tumor margins. Therefore, we evaluated four supervised classification algorithms: random forest, support vector machines (SVM), multilayer perceptron, and k-nearest neighbors to differentiate malignant from healthy tissue based on HSI recordings of esophago-gastric resectates in 11 patients.

RESULTS

The best performances were obtained with a cancerous tissue detection of 63% sensitivity and 69% specificity with the SVM. In a leave-one patient-out cross-validation, the classification showed larger performance differences according to the patient data used. In less than 1 s, data classification and visualization was shown.

CONCLUSION

In this work, we successfully tested several classification algorithms for the automatic detection of esophageal carcinoma in resected tissue. A larger data set and a combination of several methods would probably increase the performance. Moreover, the implementation of software tools for intraoperative tumor boundary visualization will further support the surgeon during oncologic operations.

[Minimally invasive robot-assisted gastric bypass after open Mason reduction gastroplasty]

BACKGROUND

The introduction of robot-assisted surgery in the treatment of morbidly obese patients has enlarged the armamentarium for surgeons involved in bariatric surgery. This article describes the experiences with a conversion surgery from a complicated open Mason gastroplasty to a Roux en Y gastric bypass using the da Vinci Xi robotic system.

CASE

A 29-year-old female patient underwent a Mason reduction gastroplasty by laparotomy in 1995 (body mass index BMI 53.2 kg/m²). The course was complicated with a revision due to abscess formation and subsequent secondary healing. In 1996 an open revision of the gastroplasty due to persisting gastroesophageal reflux disease and outlet stenosis with dilatation of the outlet and an open cholecystectomy for cholecystolithiasis were performed . Abdominoplasty was performed for skin flaps in 2001 after the patient had lost 68 kg in weight. The patient presented at our hospital because of insufficient weight reduction even with weight gain since 2001 and treatment-refractive gastroesophageal reflux with adhesion problems. Clinical examination revealed normal scar tissue formation with no indications for an incisional hernia. The BMI was 48.2 kg/m² with a body weight of 124 kg. The surgery was performed using a da Vinci Xi robotic system after access via a blunt dissection with the introduction of two trocars and adhesiolysis. The gastric pouch was created using Echelon 60 mm cartridges via an additional trocar. The gastroenterostomy was constructed with a 150 cm alimentary loop and a 60 cm biliodigestive loop resulting in a Roux en Y bypass. The operating time was 224 min.

RESULTS

The postoperative course was uneventful. Enteral nutrition was resumed on day 2 and the patient was discharged from the hospital 4 days postoperation.

CONCLUSION

This preliminary experience suggests that robotic revisional surgery can be performed safely even after complicated bariatric operations.

[Standardized access options for colorectal surgery with the da Vinci Xi system]

BACKGROUND

Performing colorectal surgery with previous da Vinci system generations presented some limitations that caused uncertainty for surgeons as they began to apply robotic technologies. The da Vinci Xi system is designed to overcome these limitations and to enable multiquadrant colorectal surgery.

OBJECTIVE

The design concept of the da Vinci Xi system and the standardized access for colorectal surgery are explained.

MATERIAL AND METHODS

The da Vinci Xi system applies an overhead boom that maximizes the arm workspace, minimizes interference and makes the port placement universal for standardized access. Colorectal approaches have been validated in numerous cadaver models confirming the reproducibility of the standardized access.

RESULTS

Standardized access with a straight-line port placement is possible in all colorectal applications. For right-sided hemicolectomy, a transverse abdominal approach as well as a suprapubic port placement are possible. Utilizing the same principles, left-sided colectomy, sigmoid colectomy and low anterior resections can be performed. Proctocolectomy is enabled through boom rotation and a second docking. Only minor arm-to-arm interferences occurred and were easily manageable by the bedside assistant. None of the approaches required rearrangement of the patient cart or swapping arms to different port locations.

CONCLUSION

The da Vinci Xi system enables a standardized access for colorectal surgery through a universal straight-line port placement. Learning this standard principle once enables the surgeon to apply it to all colorectal surgeries and shorten the learning curve as well as minimizing stress for both novices and experienced robotic surgeons learning a new surgical robotic platform.

Impact of preoperative patient education on the prevention of postoperative complications after major visceral surgery: the cluster randomized controlled PEDUCAT trial

Background

The prevention of postoperative complications is of prime importance after complex elective abdominal operations. Preoperative patient education may prevent postoperative complications and improve patients’ wellbeing, but evidence for its efficacy is poor. The aims of the PEDUCAT trial were (a) to assess the impact of preoperative patient education on postoperative complications and patient-reported outcomes in patients scheduled for elective complex visceral surgery and (b) to evaluate the feasibility of cluster randomization in this setting.

Methods

Adult patients (age ≥ 18 years) scheduled for elective major visceral surgery were randomly assigned in clusters to attend a preoperative education seminar or to the control group receiving the department’s standard care. Outcome measures were the postoperative complications pneumonia, deep vein thrombosis (DVT), pulmonary embolism, burst abdomen, and in-hospital fall, together with patient-reported outcomes (postoperative pain, anxiety and depression, patient satisfaction, quality of life), length of hospital stay (LOS), and postoperative mortality within 30 days after the index operation. Statistical analysis was primarily by intention to treat.

Results

In total 244 patients (60 clusters) were finally included (intervention group 138 patients; control group 106 patients). Allocation of hospital wards instead of individual patients facilitated study conduct and reduced confusion about group assignment. In the intervention and control groups respectively, pneumonia occurred in 7.4% versus 8.3% (p = 0.807), pulmonary embolism in 1.6% versus 1.0% (p = 0.707), burst abdomen in 4.2% versus 1.0% (p = 0.165), and in-hospital falls in 0.0% versus 4.2% of patients (p = 0.024). DVT did not occur in any of the patients. Mortality rates (1.4% versus 1.9%, p = 0.790) and LOS (14.2 (+/− 12.0) days versus 16.1 (+/− 15.0) days, p = 0.285) were also similar in the intervention and control groups.

Conclusions

Cluster randomization was feasible in the setting of preoperative patient education and reduced the risk of contamination effects. The results of this trial indicate good postoperative outcomes in patients undergoing major visceral surgery without superiority of preoperative patient education compared to standard patient care at a high-volume center. However, preoperative patient education is a helpful instrument not only for teaching patients but also for training the nursing staff.

Trial registration

German Clinical Trials Registry, DRKS00004226. Registered on 23 October 2012. Registered 8 days after the first enrollment.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2676-6) contains supplementary material, which is available to authorized users.

[Transparent operative training in visceral surgery : Analysis at a German university medical center]

BACKGROUND

Practical operative training in the discipline of visceral surgery is currently under discussion. Aside from surveys, data on this topic in Germany are sparse. The aim of the study was an objective collation of surgical residents' practical training in the operating room in our department.

METHODS

All surgical cases from 2015 were prospectively included. Procedures were stratified into resident and non-resident operations and complex cases with sub-steps which could potentially be performed by residents. We analyzed whether an operation or surgical sub-steps were performed by a resident. If this was not achieved, the reasons were analyzed. An anonymous online survey was conducted among employees in the surgery department regarding surgical training.

RESULTS

Out of 2896 surgical cases 1141 (39.4 %) were classified as potential resident training operations, which were actually performed by a resident in 743 cases (65.1 %). The survey showed an underestimation of this proportion, where sub-steps were assisted in 30.3 % (n = 265) of 876 potential cases. This proportion significantly increased during the observation period (p < 0.001); however, it was highly overestimated by residents as well as fellows and senior consultants. Often organizational reasons were responsible when resident operations or sub-steps were not performed by a trainee (13.1 % and 30.0 %, respectively).

CONCLUSION

The monocentric analysis per se resulted in an improvement in practical surgical training. In the training environment, assisting with sub-steps provides a great potential. Multicenter studies are needed.

2D vs. 3D imaging in laparoscopic surgery-results of a prospective randomized trial

PURPOSE

3D imaging is an upcoming technology in laparoscopic surgery, and recent studies have shown that the modern 3D technique is superior in an experimental setting. However, the first randomized controlled clinical trial in this context dates back to 1998 and showed no significant difference between 2D and 3D visualization using the first 3D generation technique, which is now more than 15 years old.

METHODS

Positive results measured in an experimental setting considering 3D imaging on surgical performance led us to initiate a randomized controlled pragmatic clinical trial to validate our findings in daily clinical routine. Standard laparoscopic operations (cholecystectomy, appendectomy) were preoperatively randomized to a 2D or 3D imaging system. We used a surgical comfort scale (Likert scale) and the Raw NASA Workload TLX for the subjective assessment of 2D and 3D imaging; the duration of surgery was also measured.

RESULTS

The results of 3D imaging were statistically significant better than 2D imaging concerning the parameters "own felt safety" and "task efficiency"; the difficulty level of the procedures in the 2D and 3D groups did not differ. Overall, the Raw NASA Workload TLX showed no significance between the groups.

CONCLUSION

3D imaging could be a possible advantage in laparoscopic surgery. The results of our clinical trial show increased personal felt safety and efficiency of the surgeon using a 3D imaging system. Overall of the procedures, the findings assessed using Likert scales in terms of own felt safety and task efficiency were statistically significant for 3D imaging. The individually perceived workload assessed with the Raw NASA TLX shows no difference. Although these findings are subjective impressions of the performing surgeons without a clear benefit for 3D technology in clinical outcome, we think that these results show the capability that 3D laparoscopy can have a positive impact while performing laparoscopic procedures.

Intraoperative wound irrigation to prevent surgical site infection after laparotomy (IOWISI): study protocol for a randomized controlled trial

Background

Postoperative surgical site infection (SSI) is one of the most common hospital infections and contributes substantially to postoperative morbidity and mortality. In addition, SSIs dramatically increase the treatment cost and length of hospital stay. Following visceral surgery by laparotomy, SSI rates are especially high (14–25%). Therefore, measures to prevent SSI in this field are urgently needed. Prophylactic intraoperative wound irrigation (IOWI) of the subcutaneous soft tissue before skin closure hypothetically represents an easy and economical option to reduce SSI rates and is already frequently used in clinical practice. However, there are currently no definite recommendations on the use of IOWI since high-level evidence supporting its use is lacking. Consequently, clinical practice varies widely. Antiseptic polyhexanide (PHX)-based solutions are approved for soft-tissue wound irrigation in surgery but have not been specifically evaluated in randomized clinical trials for the prevention of SSI following laparotomy for visceral surgery.

Methods/design

The IOWISI trial is a multicentre, randomized, observer- and patient-blinded clinical trial with three parallel treatment groups, comparing IOWI with a 0.04% PHX solution to no irrigation (test 1) or saline (test 2) before skin closure after laparotomy for visceral surgery (contamination level II–IV). The primary endpoint of the trial is the SSI rate within 30 days postoperatively. Statistical analysis of the primary endpoint measure will be based on the intention-to-treat population. The global level of significance is set at 2.5% for test 1 and 5% for test 2 and the sample size (n = 540) is determined to assure a power of 94% (test 1) and 85% (test 2).

Discussion

The IOWISI trial will provide high-level evidence as a basis for clinical recommendations regarding the use of IOWI with PHX or saline and will potentially impact on future clinical guidelines and practice. The pragmatic trial design guarantees high external validity.

Trial registration

Registered at the German Clinical Trials Register, DRKS00012251. Registered on 3 July 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2154-6) contains supplementary material, which is available to authorized users.

[Single incision laparoscopy : Current status]

BACKGROUND

Since the introduction of single incision laparoscopy (SIL), there has been disagreement among professional societies regarding a general recommendation for the use of this minimally invasive method.

OBJECTIVES

Determination of evidence-based advantages of SIL compared to multiport laparoscopy (MPL).

MATERIALS AND METHODS

Description of recent technical developments and evaluation of prospective randomized clinical trials and valid meta-analyses with regard to organ-specific procedures. In addition, an expert opinion is provided based on 4209 SIL interventions.

RESULTS

SIL is nowadays applied in all fields of general and visceral surgery. Due to the initial enthusiasm, methodologically weak studies were often published in the literature. Any beneficial effect of SIL on reduced perioperative morbidity is not clearly confirmed, yet. A better cosmetic outcome is either obvious (in SIL liver resections) or nearly unverifiable (in SIL cholecystectomies).

CONCLUSION

SIL has proven feasible and safe after getting through the learning curve. Scientific evidence is currently insufficient to justify SIL without reservation in particular without the individual technical experience of the surgeon.

[Robotics in the operating room : Out of the niche into widespread application]

In the last few years robotic surgery has progressed from being confined to a small niche to a widespread application in routine visceral surgery; however, evidence for superiority of robotic surgery compared to laparoscopy from randomized studies with a sufficient number of patients is still lacking in most fields of visceral surgery. For complex operations that necessitate an extensive reconstruction phase, such as pancreatectomy, gastrectomy and esophagectomy, there is a potential benefit for the permanent and justified use of robotic surgery. Even in operations where delicate nerve preparation and radical surgical resection are simultaneously necessary, such as rectal resection, robotic surgery may provide certain benefits. In the long term there is a great potential for the integration of innovative techniques, such as navigation or other medical imaging procedures into robotic surgery, which can currently only partially be estimated. Care must be taken to avoid premature euphoria; however, due to the assumed great potential there is an urgent need for randomized studies to evaluate the possible benefits of robotic surgical techniques in visceral surgery in order to generate evidence for the welfare of patients.

[Intraoperative multidimensional visualization]

Modern intraoperative techniques of visualization are increasingly being applied in general and visceral surgery. The combination of diverse techniques provides the possibility of multidimensional intraoperative visualization of specific anatomical structures. Thus, it is possible to differentiate between normal tissue and tumor tissue and therefore exactly define tumor margins. The aim of intraoperative visualization of tissue that is to be resected and tissue that should be spared is to lead to a rational balance between oncological and functional results. Moreover, these techniques help to analyze the physiology and integrity of tissues. Using these methods surgeons are able to analyze tissue perfusion and oxygenation. However, to date it is not clear to what extent these imaging techniques are relevant in the clinical routine. The present manuscript reviews the relevant modern visualization techniques focusing on intraoperative computed tomography and magnetic resonance imaging as well as augmented reality, fluorescence imaging and optoacoustic imaging.