Pelvic Intraoperative Neuromonitoring Prevents Dysfunction in Patients With Rectal Cancer: Results From a Multicenter, Randomized, Controlled Clinical Trial of a NEUROmonitoring System (NEUROS).

OBJECTIVE: This NEUROmonitoring System (NEUROS) trial assessed whether pelvic intraoperative neuromonitoring (pIONM) could improve urogenital and ano-(neo-)rectal functional outcomes in patients who underwent total mesorectal excisions (TMEs) for rectal cancer. BACKGROUND: High-level evidence from clinical trials is required to clarify the benefits of pIONM. METHODS: NEUROS was a 2-arm, randomized, controlled, multicenter clinical trial that included 189 patients with rectal cancer who underwent TMEs at 8 centers, from February 2013 to January 2017. TMEs were performed with pIONM (n=90) or without it (control, n=99). The groups were stratified according to neoadjuvant chemoradiotherapy and sex, with blocks of variable length. Data were analyzed according to a modified intention-to-treat protocol. The primary endpoint was a urinary function at 12 months after surgery, assessed with the International Prostate Symptom Score, a patient-reported outcome measure. Deterioration was defined as an increase of at least 5 points from the preoperative score. Secondary endpoints were sexual and anorectal functional outcomes, safety, and TME quality. RESULTS: The intention-to-treat analysis included 171 patients. Marked urinary deterioration occurred in 22/171 (13%) patients, with significantly different incidence between groups (pIONM: n=6/82, 8%; control: n=16/89, 19%; 95% confidence interval, 12.4-94.4; P =0.0382). pIONM was associated with better sexual and ano-(neo)rectal function. At least 1 serious adverse event occurred in 36/88 (41%) in the pIONM group and 53/99 (54%) in the control group, none associated with the study treatment. The groups had similar TME quality, surgery times, intraoperative complication incidence, and postoperative mortality. CONCLUSION: pIONM is safe and has the potential to improve functional outcomes in rectal cancer patients undergoing TME.

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.

Diverticulitis patient care during the Covid-19 pandemic in Germany-a retrospective nationwide population-based cohort study.

PURPOSE: Coronavirus disease 2019 (COVID-19) impacted health care systems around the world. Despite a decrease in emergency admissions, an increased number of complicated forms of diverticulitis was reported. It was the aim of this study to analyze the pandemic impact on diverticulitis management in Germany. METHODS: This is a retrospective population-wide analysis of hospital billing data (2012-2021) of diverticulitis in Germany. Patients were identified based on diagnosis (ICD10) and procedural codes to stratify by conservative and operative management. Primary outcome of interest was admission rates, secondary outcomes were rates of surgical vs conservative treatment and fraction of complicated clinical courses during the pandemic. RESULTS: Of a total of 991,579 cases, 66,424 (6.7%) were admitted during pandemic lockdowns. Conservative treatment was the most common overall (66.9%) and higher during lockdowns (70.7%). Overall admissions and population adjusted rates of surgically treated patients decreased, the latter by 12.7% and 11.3%, corrected to estimated rates, in the two lockdowns. Surgery after emergency presentation decreased by 7.1% (p=0.053) and 11.1% (p=0.002) in the two lockdowns with a higher rate of ostomy and/or revision (+5.6%, p=0.219, and +10.2%, p=0.030). In-hospital mortality was increased in lockdown periods (1.64% vs 1.49%). In detail, mortality was identical in case of conservative treatment during lockdown periods (0.5%) but was higher in surgically treated patients (4.4% vs 3.6%). CONCLUSION: During lockdowns, there was an overall decrease of admissions for diverticulitis, especially non-emergency admissions in Germany, and treatment was more likely to be conservative. In case of surgery, however, there was increased risk of a complicated course (ostomy, re-surgery), possibly due to patient selection.

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.

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.

Video: Clinical evaluation of a laparoscopic hyperspectral imaging system.

BACKGROUND: Hyperspectral imaging (HSI) during surgical procedures is a new method for perfusion quantification and tissue discrimination. Its use has been limited to open surgery due to large camera sizes, missing color video, or long acquisition times. A hand-held, laparoscopic hyperspectral camera has been developed now to overcome those disadvantages and evaluated clinically for the first time. METHODS: In a clinical evaluation study, gastrointestinal resectates of ten cancer patients were investigated using the laparoscopic hyperspectral camera. Reference data from corresponding anatomical regions were acquired with a clinically approved HSI system. An image registration process was executed that allowed for pixel-wise comparisons of spectral data and parameter images (StO2: oxygen saturation of tissue, NIR PI: near-infrared perfusion index, OHI: organ hemoglobin index, TWI: tissue water index) provided by both camera systems. The mean absolute error (MAE) and root mean square error (RMSE) served for the quantitative evaluations. Spearman's rank correlation between factors related to the study design like the time of spectral white balancing and MAE, respectively RMSE, was calculated. RESULTS: The obtained mean MAEs between the TIVITA® Tissue and the laparoscopic hyperspectral system resulted in StO2: 11% ± 7%, NIR PI: 14±3, OHI: 14± 5, and TWI: 10 ± 2. The mean RMSE between both systems was 0.1±0.03 from 500 to 750 nm and 0.15 ±0.06 from 750 to 1000 nm. Spearman's rank correlation coefficients showed no significant correlation between MAE or RMSE and influencing factors related to the study design. CONCLUSION: Qualitatively, parameter images of the laparoscopic system corresponded to those of the system for open surgery. Quantitative deviations were attributed to technical differences rather than the study design. Limitations of the presented study are addressed in current large-scale in vivo trials.

Mechanical plus oral bowel preparation with paromomycin and metronidazole reduces infectious complications in elective colorectal surgery: a matched case-control study.

PURPOSE: Infectious complications are as high as 30% in elective colorectal surgery. In recent years, several studies have discussed the topic of preoperative bowel decontamination prior to colorectal surgery in order to reduce postoperative infectious complications and have found significant effects of oral antibiotic administration with a large variety of drugs used. No study has evaluated the combination of oral paromomycin and metronidazole in this context. METHODS: We performed a prospective single-center study with a matched-pair retrospective cohort to evaluate postoperative infectious complications (superficial site infections, organ space abscess, anastomotic leakage) in elective colorectal surgery. PATIENTS: A total of 120 patients were available for study inclusion; 101 gave informed consent and were included. A total of 92 patients were matched and subsequently analyzed. We could show a reduction in overall infectious complications in the intervention group (15.2% vs 30.8%, p = 0.018; odds ratio 0.333, 95% CI 0.142-0.784) as well as a reduction in superficial surgical site infections (8.7 vs 19.6%, p = 0.041, OR 0.333, 95% CI 0.121-0.917). The frequency of the other infectious complications such as intraabdominal abscesses and anastomotic leakage showed a tendency towards decreased frequencies in the intervention group (OR 0.714, 95% CI 0.235-2.169 and OR 0.571; 95% CI 0.167-1.952, respectively). Finally, the oral antibiotic administration led to an almost significantly reduced length of stay (12.24 days vs 15.25 days; p = 0.057). CONCLUSIONS: Oral paromomycin and metronidazole with intravenous ertapenem effectively reduce infectious complications in elective colorectal surgery. TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov (NCT03759886) December 17, 2018.

Comparison of hyperspectral imaging and fluorescence angiography for the determination of the transection margin in colorectal resections-a comparative study.

PURPOSE: One relevant aspect for anastomotic leakage in colorectal surgery is blood perfusion of both ends of the anastomosis. The clinical evaluation of this issue is limited, but new methods like fluorescence angiography with indocyanine green or non-invasive and contactless hyperspectral imaging have evolved as objective parameters for perfusion evaluation. METHODS: In this prospective, non-randomized, open-label and two-arm study, fluorescence angiography and hyperspectral imaging were compared in 32 consecutive patients with each other and with the clinical assessment by the surgeon. After preparation of the bowel and determination of the surgical resection line, the tissue was evaluated with hyperspectral imaging for 5 min before and after cutting the marginal artery and assessed by 6 hyperspectral pictures followed by fluorescence angiography with indocyanine green. RESULTS: In 30 of 32 patients, the image data could be evaluated and compared. Both methods provided a comparable borderline between well-perfused and poorly perfused tissue (p = 0.704). In 15 cases, the surgical resection line was shifted to the central position due to the imaging. The border zone was sharper in fluorescence angiography and best assessed 31 s after injection. With hyperspectral imaging, the border zone was visualized wider and with more differences between proximal and distal border. CONCLUSION: Hyperspectral imaging and fluorescence angiography provide similar results in determining the perfusion border. Both methods allow a good and safe visualization of the blood perfusion at the central resection margin to create a well-perfused anastomosis. TRIAL REGISTRATION: This study was registered at Clinicaltrials.gov ( NCT04226781 ) on January 13, 2020.

Preoperative endoscopic marking of the gastrointestinal tract using fluorescence imaging: submucosal indocyanine green tattooing versus a novel fluorescent over-the-scope clip in a survival experimental study.

BACKGROUND: Intraoperative localization of endoluminal lesions is can be difficult during laparoscopy. Preoperative endoscopic marking is therefore necessary. Current methods include submucosal tattooing using visible dyes, which in case of transmural injection can impair surgical dissection. Tattooing using indocyanine green (ICG) coupled to intraoperative near-infrared (NIR) laparoscopy has been described. ICG is only visible under NIR-light, therefore, it doesn't impair the surgical workflow under white light even if there is spillage. However, ICG tattoos have rapid diffusion and short longevity. We propose fluorescent over-the-scope clips (FOSC), using a novel biocompatible fluorescent paint, as durable lesion marking. METHODS: In six pigs, gastric and colonic endoscopic tattoos using 0.05 mg/mL of ICG and markings using the fluorescent OSC were performed (T0). Simultaneously, NIR laparoscopy was executed. Follow-up laparoscopies were conducted at postoperative day (POD) 4-6 (T1) and POD 11-12 (T2). During laparoscopy, fluorescence intensity was assessed. In one human cadaver, FOSC was used to mark a site on the stomach and on the sigmoid colon, respectively. Intraoperative detection during NIR laparoscopy was assessed. RESULTS: Gastric and colonic ICG tattooing and OSC markings were easily visible using NIR laparoscopy on T0. All FOSC were visible at T1 and T2 in both stomach and colon, whereas the ICG tattooing at T1 was only visible in the stomach of 2 animals and in the colon of 3 animals. At T2, tattoos were not visible in any animal. FOSC were still visible in both stomach and colon of the human cadaver at 10 days. CONCLUSION: Endoscopic marking using FOSC can be an efficient and durable alternative to standard methods.

Quantitative serosal and mucosal optical imaging perfusion assessment in gastric conduits for esophageal surgery: an experimental study in enhanced reality.

INTRODUCTION/OBJECTIVE: Gastric conduit (GC) is used for reconstruction after esophagectomy. Anastomotic leakage (AL) incidence remains high, given the extensive disruption of the gastric circulation. Currently, there is no reliable method to intraoperatively quantify gastric perfusion. Hyperspectral imaging (HSI) has shown its potential to quantify serosal StO2. Confocal laser endomicroscopy (CLE) allows for automatic mucosal microcirculation quantification as functional capillary density area (FCD-A). The aim of this study was to quantify serosal and mucosal GC's microperfusion using HSI and CLE. Local capillary lactate (LCL) served as biomarker. METHODS: GC was formed in 5 pigs and serosal StO2% was quantified at 3 regions of interest (ROI) using HSI: fundus (ROI-F), greater curvature (ROI-C), and pylorus (ROI-P). After intravenous injection of sodium-fluorescein (0.5 g), CLE-based mucosal microperfusion was assessed at the corresponding ROIs, and LCLs were quantified via a lactate analyzer. RESULTS: StO2 and FCD-A at ROI-F (41 ± 10.6%, 3.3 ± 3.8, respectively) were significantly lower than ROI-C (68.2 ± 6.7%, p value: 0.005; 18.4 ± 7, p value: 0.01, respectively) and ROI-P (72 ± 10.4%, p value: 0.005; 15.7 ± 3.2 p value: 0.001). LCL value at ROI-F (9.6 ± 4.7 mmol/L) was significantly higher than at ROI-C (2.6 ± 1.2 mmol/L, p value: 0.04) and ROI-P (2.6 ± 1.3 mmol/L, p value: 0.04). No statistically significant difference was found in all metrics between ROI-C and ROI-P. StO2 correlated with FCD-A (Pearson's r = 0.67). The LCL correlated negatively with both FCD-A (Spearman's r = - 0.74) and StO2 (Spearman's r = - 0.54). CONCLUSIONS: GC formation causes a drop in serosal and mucosal fundic perfusion. HSI and CLE correlate well and might become useful intraoperative tools.

[New intraoperative fluorescence-based and spectroscopic imaging techniques in visceral medicine - precision surgery in the "high tech"-operating room]. / Neue intraoperative fluoreszenzbasierte und spektroskopische Bildgebungsverfahren in der Viszeralmedizin ­ Präzisionschirurgie im "Hightech"-OP.

INTRODUCTION: Fluorescence angiography (FA) with indocyanine green (ICG) and hyperspectral imaging (HSI) are novel intraoperative visualization techniques in abdominal, vascular and transplant surgery. With the purpose of precision surgery, and in order to increase patient's safety, these new tools aim at reducing postoperative morbidity and mortality. This review discusses and highlights recent developments and the future potential of real-time imaging modalities. METHODS: The underlying mechanisms of the novel imaging methods and their clinical impact are displayed in the context of avoiding anastomotic leaks, the most momentous complications in gastrointestinal surgery after oncologic resections. RESULTS: While FA is associated with the admission of a fluorescence agent, HSI is contact-free and non-invasive. Both methods are able to record physiological tissue properties in real-time. Additionally, FA also measures dynamic phenomena. The techniques take a few seconds only and do not hamper the operative workflow considerably. With regard to a potential change of the surgical strategy, FA and HSI have an equal significance. Our own advancements reflect, in particular, the topics of data visualization and automated data analyses together with the implementation of artificial intelligence (AI) and minimalization of the current devices to install them into endoscopes, minimal-invasive and robot-guided surgery. CONCLUSION: There are a limited number of studies in the field of intraoperative imaging techniques. Whether precision surgery in the "high-tech" OR together with FA, HSI and robotics will result in more secure operative procedures to minimize the postoperative morbidity and mortality will have to be evaluated in future multicenter trials.

Interrupted sutures prevent recurrent abdominal fascial dehiscence: a comparative retrospective single center cohort analysis of risk factors of burst abdomen and its recurrence as well as surgical repair techniques.

BACKGROUND: Burst abdomen (BA) is a severe complication after abdominal surgery, which often requires urgent repair. However, evidence on surgical techniques to prevent burst abdomen recurrence (BAR) is scarce. METHODS: We conducted a retrospective analysis of patients with BA comparing them to patients with superficial surgical site infections from the years 2015 to 2018. The data was retrieved from the institutional wound register. We analyzed risk factors for BA occurrence as well as its recurrence after BA repair and surgical closure techniques that would best prevent BAR. RESULTS: We included 504 patients in the analysis, 111 of those suffered from BA. We found intestinal resection (OR 172.510; 22.195-1340.796, p < 0.001), liver cirrhosis (OR 4.788; 2.034-11.269, p < 0.001) and emergency surgery (OR 1.658; 1.050-2.617; p = 0.03) as well as postoperative delirium (OR 5.058; 1.349-18.965, p = 0.016) as the main predictor for developing BA. The main reason for BA was superficial surgical site infection (40.7%). 110 patients received operative revision of the abdominal fascial dehiscence and 108 were eligible for BAR analysis with 14 cases of BAR. Again, post-operative delirium was the patient-related predictor for BAR (OR 13.73; 95% CI 1.812-104-023, p = 0.011). The surgical technique of using interrupted sutures opposed to continuous sutures showed a preventive effect on BAR (OR 0.143, 95% CI 0.026-0,784, p = 0.025). The implantation of an absorbable IPOM mesh did not reduce BAR, but it did reduce the necessity of BAR revision significantly. CONCLUSION: The use of interrupted sutures together with the implantation of an intraabdominal mesh in burst abdomen repair helps to reduce BAR and the need for additional revision surgeries.

Precision Surgery In Rectal Resection With Hyperspectral and Fluorescence Imaging And Pelvic Intraoperative Neuromonitoring (With Video).

Oncologic visceral surgery has recently been revolutionized by robotics, artificial intelligence (AI), sparing of functionally important structures and innovative intraoperative imaging tools. These techniques enable new dimensions of precision surgery and oncology. Currently, data-driven, cognitive operating rooms are standing at the forefront of the latest technical and didactic developments in abdominal surgery. Rectal low anterior resection with total mesorectal excision (TME) for lower- and middle-third rectal cancer is a challenging operation due to the narrow pelvis and the tender guiding structures. Thus, new approaches have been needed to simplify the procedure and to upgrade the results. The combination of robotics with pelvic intraoperative neuromonitoring (pIONM) and new possibilities of visualization, such as multi- and hyperspectral imaging (MSI / HSI) or fluorescence imaging (FI) with indocyanine green (ICG) is a forward-looking modality to enhance surgical precision and reduce postoperative complications while improving oncologic and functional outcomes with a better quality of life. The aim of our video-paper is to show how to achieve maximum precision by combining robotic surgery with pelvic intraoperative neuromonitoring and new imaging devices for rectal cancer.

Hyperspectral Imaging (HSI) in Acute Mesenteric Ischemia to Detect Intestinal Perfusion Deficits.

BACKGROUND: Acute mesenteric ischemia is a life-threatening acute condition, which requires an interdisciplinary approach, including vascular recanalization and surgical treatment. Visual evaluation of intestinal perfusion might be misleading, and therefore, additional tools are necessary to reliably be able to resect the ischemic intestine. Hyperspectral imaging (HSI) has been shown to be feasible and safe for real-time assessment of tissue perfusion in visceral surgery but has never been used in cases of acute mesenteric ischemia. Therefore, we applied HSI in acute mesenteric ischemia to evaluate it for potential aid in the objectively discriminating ischemic and well-perfused intestine during explorative laparotomy. METHODS: We recorded HSI measurements in 11 cases of acute mesenteric ischemia during explorative laparotomy. We evaluated the recorded images for macroscopic visual perfusion quality and divided it into three groups. Of those three groups, we calculated and compared the HSI indexes of tissue saturation, near-infrared perfusion index, organ hemoglobin index, and tissue water index, as well as the reflectance spectra. RESULTS: We found significant differences in tissue saturation (0.7% versus 0.45%; P = 0.002) and near-infrared perfusion index (0.58 versus 0.23; P < 0.001) in poorly perfused intestinal segments compared with the viable intestine. Furthermore, we could detect an increasing peak at 630 nm of the reflectance spectra in less viable tissues, indicating a maximum in necrotic tissues. We attributed this peak to an increase in met-hemoglobin content in necrotic tissues, which is supported by the increase in the HSI organ hemoglobin index. CONCLUSIONS: HSI is able to discriminate tissue perfusion in acute mesenteric ischemia reliably and therefore might be helpful for resection. In addition, HSI gives information on tissue viability via reflectance spectra.

Incisional negative pressure wound therapy does not reduce surgical site infections in abdominal midline incisions: a case control study.

Purpose: There is evidence from various surgical specialties that incisional negative pressure wound therapy (iNPWT) might reduce postoperative surgical site infections (SSIs). In visceral and general surgery, there is varying evidence of its efficacy in reducing surgical site infections.Methods: A prospectively registered patient cohort of 43 patients with abdominal wall and visceral surgery received treatment with iNPWT and was compared to a matched retrospective cohort to analyze its effects on SSI occurrence and respective risk factors. Groups were matched by procedure, sex, body mass index and age. We used two different systems of iNPWT: (i) PREVENATM or (ii) self-made epicutaneous iNPWT from common VAC material.Results: We could not find a total reduction in postoperative SSIs by application of iNPWT. But within the iNPWT cohort, patients with self-made iNPWT suffered more often from SSIs compared to the commercial iNPWT subgroup. No patient specific risk factors could be identified to advocate the use of iNPWT.Conclusion: Our data do not support the use of an incisional negative pressure wound therapy on closed wounds in midline laparotomy incisions. Although, differences exist between the commmercial and self-made systems.

In-depth characterization of the Wnt-signaling/ß-catenin pathway in an in vitro model of Barrett's sequence.

BACKGROUND: An altered Wnt-signaling activation has been reported during Barrett's esophagus progression, but with rarely detected mutations in APC and ß-catenin (CTNNB1) genes. METHODS: In this study, a robust in-depth expression pattern analysis of frizzled receptors, co-receptors, the Wnt-ligands Wnt3a and Wnt5a, the Wnt-signaling downstream targets Axin2, and CyclinD1, as well as the activation of the intracellular signaling kinases Akt and GSK3ß was performed in an in vitro cell culture model of Barrett's esophagus. Representing the Barrett's sequence, we used normal esophageal squamous epithelium (EPC-1, EPC-2), metaplasia (CP-A) and dysplasia (CP-B) to esophageal adenocarcinoma (EAC) cell lines (OE33, OE19) and primary specimens of squamous epithelium, metaplasia and EAC. RESULTS: A loss of Wnt3a expression was observed beginning from the metaplastic cell line CP-A towards dysplasia (CP-B) and EAC (OE33 and OE19), confirmed by a lower staining index of WNT3A in Barrett's metaplasia and EAC, than in squamous epithelium specimens. Frizzled 1-10 expression analysis revealed a distinct expression pattern, showing the highest expression for Fzd2, Fzd3, Fzd4, Fzd5, Fzd7, and the co-receptor LRP5/6 in EAC cells, while Fzd3 and Fzd7 were rarely expressed in primary specimens from squamous epithelium. CONCLUSION: Despite the absence of an in-depth characterization of Wnt-signaling-associated receptors in Barrett's esophagus, by showing variations of the Fzd- and co-receptor profiles, we provide evidence to have a significant role during Barrett's progression and the underlying pathological mechanisms.

Determination of the transection margin during colorectal resection with hyperspectral imaging (HSI).

PURPOSE: This study evaluated the use of hyperspectral imaging for the determination of the resection margin during colorectal resections instead of clinical macroscopic assessment. METHODS: The used hyperspectral camera is able to record light spectra from 500 to 1000 nm and provides information about physiologic parameters of the recorded tissue area intraoperatively (e.g., tissue oxygenation and perfusion). We performed an open-label, single-arm, and non-randomized intervention clinical trial to compare clinical assessment and hyperspectral measurement to define the resection margin in 24 patients before and after separation of the marginal artery over 15 min; HSI was performed each minute to assess the parameters mentioned above. RESULTS: The false color images calculated from the hyperspectral data visualized the margin of perfusion in 20 out of 24 patients precisely. In the other four patients, the perfusion difference could be displayed with additional evaluation software. In all cases, there was a deviation between the transection line planed by the surgeon and the border line visualized by HSI (median 1 mm; range - 13 to 13 mm). Tissue perfusion dropped up to 12% within the first 10 mm distal to the border line. Therefore, the resection area was corrected proximally in five cases due to HSI record. The biggest drop in perfusion took place in less than 2 min after devascularization. CONCLUSION: Determination of the resection margin by HSI provides the surgeon with an objective decision aid for assessment of the best possible perfusion and ideal anastomotic area in colorectal surgery.

Evaluation of hyperspectral imaging (HSI) for the measurement of ischemic conditioning effects of the gastric conduit during esophagectomy.

BACKGROUND: Hyperspectral imaging (HSI) is a relatively new method used in image-guided and precision surgery, which has shown promising results for characterization of tissues and assessment of physiologic tissue parameters. Previous methods used for analysis of preconditioning concepts in patients and animal models have shown several limitations of application. The aim of this study was to evaluate HSI for the measurement of ischemic conditioning effects during esophagectomy. METHODS: Intraoperative hyperspectral images of the gastric tube through the mini-thoracotomy were recorded from n = 22 patients, 14 of whom underwent laparoscopic gastrolysis and ischemic conditioning of the stomach with two-step transthoracic esophagectomy and gastric pull-up with intrathoracic anastomosis after 3-7 days. The tip of the gastric tube (later esophagogastric anastomosis) was measured with HSI. Analysis software provides a RGB image and 4 false color images representing physiologic parameters of the recorded tissue area intraoperatively. These parameters contain tissue oxygenation (StO2), perfusion-(NIR Perfusion Index), organ hemoglobin (OHI), and tissue water index (TWI). RESULTS: Intraoperative HSI of the gastric conduit was possible in all patients and did not prolong the regular operative procedure due to its quick applicability. In particular, the tissue oxygenation of the gastric conduit was significantly higher in patients who underwent ischemic conditioning ([Formula: see text] = 78%; [Formula: see text] = 66%; p = 0.03). CONCLUSIONS: HSI is suitable for contact-free, non-invasive, and intraoperative evaluation of physiological tissue parameters within gastric conduits. Therefore, HSI is a valuable method for evaluating ischemic conditioning effects and may contribute to reduce anastomotic complications. Additional studies are needed to establish normal values and thresholds of the presented parameters for the gastric conduit anastomotic site.

Severe ileocecal inflammatory syndrome in adult patients with cystic fibrosis.

The relevance of gastrointestinal manifestations of cystic fibrosis (CF) is increasing due to an improved life expectancy. We report on 2 adult patients with prior lung transplantation who presented with a severe inflammatory disorder of the ileocecal region. One patient underwent ileocecal resection; the second patient died after emergency surgery for intestinal perforation. Both cases did not show typical signs of CF-related distal intestinal obstruction syndrome or extensive fibrosing colonopathy. However, the clinical and histopathological findings revealed CF-induced inflammatory alterations of the intestinal mucosa. Thus, these cases illustrate a further CF-related bowel disorder, which can be especially relevant in long-term CF survivors.