Sidedness is not a prognostic factor in an unselected cohort of patients with colon cancer but prognosis for caecal carcinoma is worse - A multivariate analysis of a large single institution database.

PURPOSE: Sidedness has emerged as a prognostic factor for metastatic colorectal cancer treated with modern systemic therapies. This study investigates whether it is also relevant for an unselected patient cohort including all stages. METHODS: All consecutive patients admitted with colon cancer between 1995 and 2018 were retrieved from an institution-held database. Patients were divided into two cohorts. The first cohort included patients without distant metastases who were able to undergo curative resection. The second cohort presented with distant metastases (stage IV). Potentially prognostic factors were subjected to multivariate Cox Regression analysis. RESULTS: Overall, 1,606 patients met the inclusion and exclusion criteria. An R0-resection was achieved in 1,222 patients without distant metastases. Five-year cause-specific survival rate was 89.3% for this group. There was no difference between right- and left-sided cancers (88.2% vs. 90.1%, p = 0.220). However, prognosis of caecal carcinoma was significantly worse than that of all other sites combined (83.5% vs. 90.2%, p = 0.007). In multivariate analysis, pT-category, pN-category, grading, vascular invasion, emergency operation, adjuvant chemotherapy, and caecal carcinoma remained as independent prognostic factors. In the 384 patients with stage IV-disease, 3-year overall survival for right- vs. left-sided cancers differed only in univariate analysis (17.7% vs. 28.6%, p = 0.013). CONCLUSION: In non-metastatic colon cancer, location in the caecum is an independent prognostic factor. In unselected patients with stage IV colon cancer, sidedness was not found to be a prognostic factor. Differentiation into right- and left-sided tumors may be simplistic, and further studies on the biological behavior of different colonic sites are warranted.

Intraoperative Laparoscopic Hyperspectral Imaging during Esophagectomy-A Pilot Study Evaluating Esophagogastric Perfusion at the Anastomotic Sites.

Hyperspectral imaging (HSI) is a non-invasive and contactless technique that enables the real-time acquisition of comprehensive information on tissue within the surgical field. In this pilot study, we investigated whether a new HSI system for minimally-invasive surgery, TIVITA® Mini (HSI-MIS), provides reliable insights into tissue perfusion of the proximal and distal esophagogastric anastomotic sites during 21 laparoscopic/thoracoscopic or robotic Ivor Lewis esophagectomies of patients with cancer to minimize the risk of dreaded anastomotic insufficiency. In this pioneering investigation, physiological tissue parameters were derived from HSI measurements of the proximal site of the anastomosis (esophageal stump) and the distal site of the anastomosis (tip of the gastric conduit) during the thoracic phase of the procedure. Tissue oxygenation (StO2), Near Infrared Perfusion Index (NIR-PI), and Tissue Water Index (TWI) showed similar median values at both anastomotic sites. Significant differences were observed only for NIR-PI (median: 76.5 vs. 63.9; p = 0.012) at the distal site (gastric conduit) compared to our previous study using an HSI system for open surgery. For all 21 patients, reliable and informative measurements were attainable, confirming the feasibility of HSI-MIS to assess anastomotic viability. Further studies on the added benefit of this new technique aiming to reduce anastomotic insufficiency are warranted.

Visceral obesity determined in routine preoperative CT scans predicts risk of postoperative burst abdomen.

Burst abdomen (BA) remains a severe postoperative complication after abdominal surgery. Obesity is a known risk factor for postoperative complications but objective parameters such as body mass index fail to predict BA after abdominal surgery. In recent literature, CT-derived body composition assessment could predict obesity-related diseases and surgical site infections. We report data from the institutional wound register, comparing patients with BA to a subgroup of patients without BA. The CT images were evaluated for intraabdominal and subcutaneous fat tissues. Univariate and multivariate risk factor analysis was performed in order to evaluate CT-derived obesity parameters as risk factor for BA. 92 patients with BA were compared to 32 controls. Patients with BA had significantly more visceral obesity (VO; p < 0.001) but less subcutaneous obesity (SCO) on CT scans. VO and SCO both were positively correlated with BMI (r = 0.452 and 0.572) but VO and SCO were inversely correlated (r = -0.189). Multivariate analysis revealed VO as significant risk factor for postoperative BA (OR 1.257; 95% CI 1.084-1.459; p = 0.003). Our analysis of patients with postoperative BA revealed VO as major risk factor for postoperative BA. Thus, preoperative CT scans gives valuable information on possible risk stratification.

The impact of chronic obstructive pulmonary disease on surgical outcomes after surgery for an acute abdominal diagnosis.

PURPOSE: The current study was undertaken to describe the independent contribution of chronic obstructive pulmonary disease (COPD) to the risk of postoperative morbidity and in-hospital mortality among patients undergoing surgery for an acute abdominal diagnosis. METHODS: Patients who underwent emergency abdominal procedures were identified from the electronic database of the Department of Visceral, Transplantation, Thoracic and Vascular Surgery of our institution. To evaluate differences in surgical risk associated with COPD, patients with COPD were matched for age, sex, and type of surgery with an equal number of controls who did not have COPD. Logistic regression was performed to evaluate the univariate and multivariate associations between the independent variables, including COPD and outcome variables. RESULTS: Between January 2012 and December 2022, 3519 patients undergoing abdominal emergency surgery were identified in our abdominal surgical department. After removing ineligible cases, 201 COPD cases with an equal number of matched controls remained for analysis. The prevalence of COPD after the exclusion of ineligible cases was 5.7%. There were statistically significant differences in the rate of postoperative pulmonary complications (PPCs [57.7% vs. 35.8%; P < 0.001]), ventilator dependence (VD [63.2% vs. 46.3%; P < 0.001]), thromboembolic events (TEEs [22.9% vs. 12.9%; P = 0.009]), and in-hospital mortality (41.3% vs. 30.8%; P = 029) for patients with and without COPD. Independent of other covariates, the presence of COPD was not associated with a significantly increased risk of in-hospital mortality (OR, 1.16; 95% CI 0.70-1.97; P = 0.591) but was associated with an increased risk of PPCs (OR, 2.49; 95% CI 1.41-4.14; P = 0.002) and VD (OR, 2.26; 95% CI 1.22-4.17; P = 0.009). CONCLUSIONS: Preexisting COPD may alter a patient's risk of PPCs and VD. However, it was not associated with an increased risk of in-hospital mortality.

Computed Tomography-Defined Body Composition as Prognostic Parameter in Acute Mesenteric Ischemia.

INTRODUCTION: Body composition comprising low-skeletal muscle mass (LSMM) and subcutaneous and visceral adipose tissue (SAT and VAT) can be assessed by using cross-sectional imaging modalities. Previous analyses suggest that these parameters harbor prognostic relevance in various diseases. Aim of this study was to analyze possible associations of body composition parameters on mortality in patients with clinically suspected acute mesenteric ischemia (AMI). METHODS: All patients with clinically suspected AMI were retrospectively assessed between 2016 and 2020. Overall, 137 patients (52 female patients, 37.9%) with a median age of 71 years were included in the present analysis. For all patients, the preoperative abdominal computed tomography (CT) was used to calculate LSMM, VAT, and SAT. RESULTS: Overall, 94 patients (68.6%) of the patient cohort died within 30 days within a median of 2 days, range 1-39 days. Of these, 27 patients (19.7%) died within 24 h. According to the CT, 101 patients (73.7%) were classified as being visceral obese, 102 patients (74.5%) as being sarcopenic, and 69 patients (50.4%) as being sarcopenic obese. Skeletal muscle index (SMI) was lower in non-survivors compared to survivors (37.5 ± 12.4 cm2/m2 vs. 44.1 ± 13.9 cm2/m2, p = 0.01). There were no associations between body composition parameters with mortality in days (SMI r = 0.07, p = 0.48, SAT r = -0.03, p = 0.77, and VAT r = 0.04, p = 0.68, respectively). In Cox regression analysis, a nonsignificant trend for visceral obesity was observed (HR: 0.62, 95% CI: 0.36-1.05, p = 0.07). CONCLUSION: SMI might be a valuable CT-based parameter, which could help discriminate between survivors and non-survivors. Further studies are needed to elucidate the associations between body composition and survival in patients with AMI.

Barrett`s Esophagus in Bariatric Surgery: Regression or Progression?

INTRODUCTION: Morbid obesity is well known as a risk factor for gastroesophageal reflux disease (GERD) and its related disorders such as Barrett's esophagus (BE). This study aimed to evaluate the development of BE in patients who underwent bariatric surgery. MATERIALS AND METHODS: Using a single-center prospectively established database of obese patients who underwent bariatric surgery from 01/2012 to 12/2019, we retrospectively compared the preoperative endoscopic findings of BE to those after 1-2 years and 3-5 years following bariatric surgery. The change of BE was detected endoscopically according to Prague classification and histologically according to the British guidelines of detecting columnar epithelium on the distal esophagus. RESULTS: Among 914 obese patients who underwent bariatric surgery and received a preoperative esophagogastroduodenoscopy (EGD), we found 119 patients (13%) with BE. A follow-up EGD was performed in 74 of the BE patients (62.2%). A total of 37 (50%) patients underwent a follow-up EGD after 1-2 years and 45 (60.8%) patients underwent it after 3-5 years. Among many clinical parameters, the surgical procedure was the only significant factor for the change of BE after bariatric surgery (p < 0.05). A regression of BE was found in 19 patients (n = 54, 35%) after laparoscopic Roux-en-Y- gastric bypass (LRYGB). Furthermore, a progression of BE was detected in six patients (n = 20, 30%) after laparoscopic sleeve gastrectomy (LSG). CONCLUSION: RYGB should be considered in obese patients with BE. Detecting BE prior to bariatric surgery may have an impact on decision-making regarding the suitable surgical bariatric procedure.

Vascular Injury During Lumbar Disc Surgery: Case Report.

A retroperitoneal organ injury-vascular injury or solid organ injury-that occurs during lumbar disc surgery needs to be dealt with adequately, because otherwise it could result in a poor (or, even, fatal) outcome of a "simple" procedure. Vascular injuries require special attention from the neurosurgical side (think of the possibility!) and cooperation between neurosurgeons and abdominal/vascular surgeons. In the presented case of a very obese female patient, a bite injury of the aorta during L3/4 disc surgery led to delayed intra-abdominal hemorrhage, which then required an emergency abdominal operation followed by major thromboembolic complication, and ultimately resulted in amputation of the patient's healthy leg. Pitfalls in intraoperative diagnosis and postoperative care are discussed, along with related medicolegal issues.

[Anastomotic techniques in minimally invasive bariatric surgery]. / Anastomosentechniken in der minimal-invasiven bariatrischen Chirurgie.

BACKGROUND: Recommendations for the use of specific anastomotic techniques are not available in laparoscopic bariatric surgery. Recommendation criteria should consider the rate of insufficiency, bleeding, tendency to stricture or ulceration as well as the impact on weight loss or dumping. OBJECTIVE: This article gives a review of the available evidence on the anastomotic techniques of typical surgical procedures in laparoscopic bariatric surgery. MATERIAL AND METHODS: The current literature was reviewed and is discussed regarding anastomotic techniques for Roux-en­Y gastric bypass (RYGB), one-anastomosis gastric bypass (OAGB), single anastomosis sleeve ileal (SASI) bypass and biliopancreatic diversion with duodenal switch (BPD-DS). RESULTS: Few comparative studies exist, except for the RYGB. In RYGB gastrojejunostomy, a complete manual suture was shown to be equivalent to a mechanical anastomosis. In addition, the linear staple suture showed slight advantages over the circular stapler in terms of wound infections and bleeding. The anastomosis technique of the OAGB and SASI can be performed entirely with a linear stapler or with suture closure of the anterior wall defect. There seems to be an advantage of manual anastomosis in BPD-DS. CONCLUSION: Due to the lack of evidence, no recommendations can be made. Only in RYGB was there an advantage of the linear stapler technique with hand closure of the stapler defect compared to the linear stapler. In principle, prospective, randomized studies should be strived for.

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.

The role of intraoperative hyperspectral imaging (HSI) in colon interposition after esophagectomy.

BACKGROUND: Colon conduit is an alternative approach to reconstructing the alimentary tract after esophagectomy. Hyperspectral imaging (HSI) has been demonstrated to be effective for evaluating the perfusion of gastric conduits, but not colon conduits. This is the first study to describe this new tool addressing image-guided surgery and supporting esophageal surgeons to select the optimal colon segment for the conduit and anastomotic site intraoperatively. PATIENTS AND METHODS: Of 10 patients, eight who underwent reconstruction with a long-segment colon conduit after esophagectomy between 01/05/2018 and 01/04/2022 were included in this study. HSI was recorded at the root and tip of the colon conduit after clamping the middle colic vessels, allowing us to evaluate the perfusion and appropriate part of the colon segment. RESULTS: Anastomotic leak (AL) was detected in only one (12.5%) of all the enrolled patients (n = 8). None of the patients developed conduit necrosis. Only one patient required re-anastomosis on postoperative day 4. No patient needed conduit removal, esophageal diversion, or stent placement. There was a change in the anastomosis site to proximal in two patients intraoperatively. There was no need to change the side of colon conduit intraoperatively in any patient. CONCLUSION: HSI is a promising and novel intraoperative imaging tool to objectively assess the perfusion of the colon conduit. It helps the surgeon to define the best perfused anastomosis site and the side of colon conduit in this type of operation.

In vivo evaluation of a hyperspectral imaging system for minimally invasive surgery (HSI-MIS).

BACKGROUND: Hyperspectral Imaging (HSI) is a reliable and safe imaging method for taking intraoperative perfusion measurements. This is the first study translating intraoperative HSI to an in vivo laparoscopic setting using a CE-certified HSI-system for minimally invasive surgery (HSI-MIS). We aim to compare it to an established HSI-system for open surgery (HSI-Open). METHODS: Intraoperative HSI was done using the HSI-MIS and HSI-Open at the Region of Interest (ROI). 19 patients undergoing gastrointestinal resections were analyzed in this study. The HSI-MIS-acquired images were aligned with those from the HSI-Open, and spectra and parameter images were compared pixel-wise. We calculated the Mean Absolute Error (MAE) for Tissue Oxygen Saturation (StO2), Near-Infrared Perfusion Index (NIR-PI), Tissue Water Index (TWI), and Organ Hemoglobin Index (OHI), as well as the Root Mean Squared Error (RMSE) over the whole spectrum. Our analysis of parameters was optimized using partial least squares (PLS) regression. Two experienced surgeons carried out an additional color-change analysis, comparing the ROI images and deciding whether they provided the same (acceptable) or different visual information (rejected). RESULTS: HSI and subsequent image registration was possible in 19 patients. MAE results for the original calculation were StO2 orig. 17.2% (± 7.7%), NIR-PIorig. 16.0 (± 9.5), TWIorig. 18.1 (± 7.9), OHIorig. 14.4 (± 4.5). For the PLS calculation, they were StO2 PLS 12.6% (± 5.2%), NIR-PIPLS 10.3 (± 6.0), TWIPLS 10.6 (± 5.1), and OHIPLS 11.6 (± 3.0). The RMSE between both systems was 0.14 (± 0.06). In the color-change analysis; both surgeons accepted more images generated using the PLS method. CONCLUSION: Intraoperative HSI-MIS is a new technology and holds great potential for future applications in surgery. Parameter deviations are attributable to technical differences and can be reduced by applying improved calculation methods. This study is an important step toward the clinical implementation of HSI for minimally invasive surgery.

Alternative intraoperative optical imaging modalities for fluorescence angiography in gastrointestinal surgery: spectral imaging and imaging photoplethysmography.

INTRODUCTION: Intraoperative near-infrared fluorescence angiography with indocyanine green (ICG-FA) is a well-established modality in gastrointestinal surgery. Its main drawback is the application of a fluorescent agent with possible side effects for patients. The goal of this review paper is the presentation of alternative, non-invasive optical imaging methods and their comparison with ICG-FA. MATERIAL AND METHODS: The principles of ICG-FA, spectral imaging, imaging photoplethysmography (iPPG), and their applications in gastrointestinal surgery are described based on selected published works. RESULTS: The main applications of the three modalities are the evaluation of tissue perfusion, the identification of risk structures, and tissue segmentation or classification. While the ICG-FA images are mainly evaluated visually, leading to subjective interpretations, quantitative physiological parameters and tissue segmentation are provided in spectral imaging and iPPG. The combination of ICG-FA and spectral imaging is a promising method. CONCLUSIONS: Non-invasive spectral imaging and iPPG have shown promising results in gastrointestinal surgery. They can overcome the main drawbacks of ICG-FA, i.e. the use of contrast agents, the lack of quantitative analysis, repeatability, and a difficult standardization of the acquisition. Further technical improvements and clinical evaluations are necessary to establish them in daily clinical routine.

GWAS meta-analysis of 16 790 patients with Barrett's oesophagus and oesophageal adenocarcinoma identifies 16 novel genetic risk loci and provides insights into disease aetiology beyond the single marker level.

OBJECTIVE: Oesophageal cancer (EC) is the sixth leading cause of cancer-related deaths. Oesophageal adenocarcinoma (EA), with Barrett's oesophagus (BE) as a precursor lesion, is the most prevalent EC subtype in the Western world. This study aims to contribute to better understand the genetic causes of BE/EA by leveraging genome wide association studies (GWAS), genetic correlation analyses and polygenic risk modelling. DESIGN: We combined data from previous GWAS with new cohorts, increasing the sample size to 16 790 BE/EA cases and 32 476 controls. We also carried out a transcriptome wide association study (TWAS) using expression data from disease-relevant tissues to identify BE/EA candidate genes. To investigate the relationship with reported BE/EA risk factors, a linkage disequilibrium score regression (LDSR) analysis was performed. BE/EA risk models were developed combining clinical/lifestyle risk factors with polygenic risk scores (PRS) derived from the GWAS meta-analysis. RESULTS: The GWAS meta-analysis identified 27 BE and/or EA risk loci, 11 of which were novel. The TWAS identified promising BE/EA candidate genes at seven GWAS loci and at five additional risk loci. The LDSR analysis led to the identification of novel genetic correlations and pointed to differences in BE and EA aetiology. Gastro-oesophageal reflux disease appeared to contribute stronger to the metaplastic BE transformation than to EA development. Finally, combining PRS with BE/EA risk factors improved the performance of the risk models. CONCLUSION: Our findings provide further insights into BE/EA aetiology and its relationship to risk factors. The results lay the foundation for future follow-up studies to identify underlying disease mechanisms and improving risk prediction.