Georg Kähler’s research while affiliated with Heidelberg University and other places

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Publications (108)


Endoscopic papillectomy versus surgical ampullectomy for adenomas and early cancers of the papilla: a retrospective Pancreas2000/European Pancreatic Club analysis
  • Article

December 2024

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225 Reads

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1 Citation

Gut

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Christian Heise

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Einas Abou-Ali

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[...]

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Objective Ampullary neoplastic lesions can be resected by endoscopic papillectomy (EP) or transduodenal surgical ampullectomy (TSA) while pancreaticoduodenectomy is reserved for more advanced lesions. We present the largest retrospective comparative study analysing EP and TSA. Design Of all patients in the database, lesions with prior interventions, benign histology advanced malignancy (T2 and more), patients with hereditary syndromes and those undergoing pancreatoduodenectomy were excluded. All remaining cases as well as a subgroup of them, after propensity-score matching (nearest-neighbour-method) based on age, gender, anthropometrics, comorbidities, size and histological subtype, were analysed. The median follow-up was 21 months (IQR 10–47) after the primary intervention. Primary outcomes were rates of complete resection (R0) and complications. Groups were compared by Fisher’s exact or χ ² test, Mann-Whitney-U-test and log-rank test for survival. Results Of 1673 patients in the database, 1422 underwent EP and 251 TSA. Of them, 23.2% were excluded for missing or inconclusive data and 19.8% of patients for prior interventions or hereditary syndromes. Final histology showed in 24.2% of EP and 14.8% of TSA patients a histology other than adenoma or adenocarcinoma while advanced cancers were recorded in 10.9% of EP and 36.6% of TSA patients. Finally, 569 EP and 63 TSA were included in the overall analysis, with a higher rate of more advanced cases and higher R0 resection rates in the TSA groups (90.5% vs 73.1%; p<0.01), with additional ablation in the EP group in 14.4%. Severe adverse event rates were 3.2% (TSA) vs 1.9% (EP). Recurrence after histological R0 resection was 16% (EP) vs 3.2% (TSA; p=0.01), and additional therapy for R1 resection was applied in 67% of the 159 cases. Propensity-score-based matching identified 62 pairs of EP/TSA patients with comparable baseline patient and lesion characteristics. The initial R0-rate was 72.6% (EP) compared with 90.3% (TSA, p=0.02) with recurrences found in 8% (EP) vs 3.2% (TSA; p=0.07); reinterventions were more frequent in the EP group. Overall survival was comparable. Conclusions The rate of patients with poor indications due to non-neoplastic disease or advanced cancer is still high for both EP and TSA; multiple retreatments were necessary for EP. Although EP can be considered an appropriate primary therapy for certain ampullary adenomas, case selection for both therapies (especially with regard to the best step-up approach) should be studied further.


ESD of 45mm large LST granular type, homogenous. a The anal margin of the lesion grows into the squamous epithelium of the anal canal. b Visualization of the marked lesion in retroflex view. c Markings on the anal side of the lesion in the squamous epithelium of the anal canal. d Resection defect in the anal canal. e Mucosal defect after completion of the ESD in retroflex view. f ESD specimen: 45 × 40mm large tubular adenoma with high-grade dysplasia—complete en bloc resection with free deep and lateral margins
ESD of an 120mm large LST granular mixed type with occult carcinoma (pocket creation method). a Visualization of the lesion in retroflex view. b The lesion reaches the oral end of the anal canal. c Marking of the anal resection margin in the squamous epithelium of the anal canal. d Submucosal injection in the anal canal. e Epithelial incision and entering the submucosal plane at the oral part of the anal canal. The fibers of the internal anal sphincter are visible. f Visualization of the hemorrhoidal veins in the submucosal plane. g Epithelial defect in the anal canal. The hemorrhoidal veins are visible. h Visualization of the mucosal defect in retroflex view. i ESD specimen: a pT1sm1 L0 V0 G2 adenocarcinoma within a 120 × 90mm large tubulovillous adenoma with high-grade dysplasia—complete en bloc resection with free deep and lateral margins (R0)
ESD of a 180mm large LST granular mixed type (flap method) with endoscopic follow-up. a Visualization of the Lesion in forward view. b Circumferential mucosal incision on the oral side of the lesion. c Circumferential mucosal incision in the anal canal with visualization of the hemorrhoidal veins. d Use of traction (clip-n’-line technique) after initial submucosal dissection in the anal side of the lesion. e Exposure of the submucosal plane and the muscle layer with the use of traction. f Visualization of the mucosal defect in forward view after prophylactic clipping of large vessels. g Visualization of the resection defect in the anal canal. h ESD specimen: 184 × 130mm large tubulovillous adenoma with high-grade dysplasia—complete en bloc resection with free deep and lateral margins (R0). i Endoscopic follow-up 15 months after the initial procedure showing the scar without any signs of recurrence
EMR of a 40mm large LST granular type, homogenous (Histology: tubulovillous adenoma with low-grade dysplasia). a Visualization of the adenoma in retroflex view. b Adequate lifting after submucosal injection. c pmEMR beginning on the oral side in retroflex view. d Mucosal defect after complete resection of the lesion
Endoscopic submucosal dissection versus endoscopic mucosal resection for the treatment of rectal lesions involving the dentate line
  • Article
  • Full-text available

June 2024

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100 Reads

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1 Citation

Surgical Endoscopy

Background The ideal treatment of epithelial neoplastic rectal lesions involving the dentate line is a controversial issue. Piecemeal endoscopic mucosal resection (EMR) is the most commonly used resection technique, but it is associated with high recurrence rates. Endoscopic submucosal dissection (ESD) has been shown to be safe and effective for the treatment of rectal lesions, but evidence is lacking concerning its application close to the dentate line. The aim of our study is to compare ESD and EMR for the treatment of epithelial rectal lesions involving the dentate line. Methods We identified all cases of endoscopic resections of rectal lesions involving the dentate line performed in two German high-volume centers between 2010 and 2022. Periinterventional and follow-up data were collected and retrospectively analyzed. Results We identified 68 ESDs and 62 EMRs meeting our inclusion criteria. ESD showed a significant advantage in en bloc resection rates (89.7% vs. 9.7%; P = 0.001) and complete resection rates (72.1% vs. 9.7%; P = 0.001). The overall curative resection rate was similar between both groups (ESD: 92.6%, EMR: 83.9%; P = 0.324), whereas in the subgroup of low-risk adenocarcinomas ESD was curative in 100% of the cases vs. 14% in the EMR group (P = 0.002). There was one local recurrence after ESD (1,5%) vs. 16 (25.8%) after EMR (P < 0.0001), and the EMR patients required an average of three further interventions. Conclusion ESD is superior to EMR for the treatment of epithelial rectal lesions involving the dentate line and should be considered the treatment of choice.

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Endoscopic Resection Procedures

January 2024

Endoscopic resection methods are of great importance in both diagnostics and therapy. Their level of difficulty is strongly dependent on the size and shape of the lesion. Although the application of individual methods in different organs and sections of the gastrointestinal tract varies considerably, the methods are presented here from the overarching technical aspect of their implementation; any organ-specific peculiarities are referred to in the text.


Overall survival with and without MTB
Implementation of the MTB recommendation
The role of the multidisciplinary tumor board after endoscopic resection of malignant tumors: is it worth it?

November 2023

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18 Reads

Surgical Endoscopy

Objectives The value of multidisciplinary tumor boards (MTBs) in the treatment of gastrointestinal cancer patients is well known. Most of the current evidence focuses on advanced cancer cases, whereas little is known about the effect of MTBs on early tumors, especially after endoscopic resection. The aim of our study is to evaluate the value of the MTB after endoscopic resection of malignant tumors of the gastrointestinal tract. Methods We retrospectively analyzed all endoscopically resected malignant tumors in our department between 2011 and 2019, focusing on the existence of an MDT recommendation after endoscopic resection, the MDT adherence to the current guidelines, and the implementation of the recommendation by the patients. Results We identified 198 patients fulfilling our inclusion criteria, of whom 168 (85%) were discussed in the MDT after endoscopic resection. In total, 155 of the recommendations (92%) were in accordance with the current guidelines, and 147 (88%) of them were implemented by the patients. The MDT discussion itself did not influence the overall survival, whereas the implementation of the MTB recommendation was associated with a significantly better prognosis. Deviations of the MDT recommendation from the guidelines had no effect on the overall survival. Conclusions The discussion of endoscopically resected malignant tumors in the MTB is crucial for the treatment of patients with this type of cancer, since the implementation of the MTB recommendation, even if it deviates from the current guidelines, improves the prognosis.


Endoscopic stricturoplasty with linear stapler for a persistent anastomotic stricture. a and b Anastomotic stricture after laparoscopic sigmoidectomy with side-to-side anastomosis (initial diameter 2 mm). c Stricture after initial balloon dilatation and insertion of the ARAMIS operation rectoscope. The blind end of the rectum offers enough space for the branches of the linear stapler (arrow). d Introduction of the linear stapler. e and f Insertion of one branch of the stapler through the anastomosis and of the other branch in the blind loop of the rectum. g and h Result at the end of the procedure. i Final result in the 6 months follow-up (diameter 14 mm)
Anastomotic stenosis after low anterior resection. Anastomotic stenosis with a residual diameter of 5 mm. Result 6 months after endoscopic stricturoplasty with a linear stapler. Final diameter 15 mm
Endoscopic Stricturoplasty with Linear Stapler: An Efficient Alternative for the Refractory Rectal Anastomotic Stricture

October 2023

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80 Reads

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4 Citations

Digestive Diseases and Sciences

Introduction Symptomatic anastomotic stricture is a rare but major complication after left-sided colorectal surgery. Hydraulic balloon dilatation is the first-line treatment in cases where the complication occurs, but 20% of patients present with refractory strictures after multiple sessions. Endoscopic stricturoplasty with the use of a linear stapler is a novel therapeutic alternative for those difficult cases. Materials and Methods We identified all patients in our department who underwent endoscopic stricturoplasty with a linear stapler between 2004 and 2022. The technical, periinterventional, and follow-up data of the patients were retrospectively analyzed. Results We identified nine patients who fulfilled our inclusion criteria. The procedure was technically possible in eight cases, whereas in one case, the anatomy of the anastomosis did not allow for a correct placement of the stapler. All patients with a technically successful procedure were relieved from their symptoms and could have their ostomy reversed. There was no periprocedural morbidity and mortality. Two patients presented with a recurrent stricture eight and 26 months after the initial stricturoplasty, and the procedure was successfully repeated in both cases. Conclusions Endoscopic stricturoplasty is a feasible, safe, and minimally invasive alternative for the treatment of refractory anastomotic strictures in the distal colon and rectum for patients with a suitable anatomy.


Onset Time and Characteristics of Postprocedural Bleeding after Endoscopic Resection of Colorectal Lesions: A Multicenter Retrospective Study

October 2023

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32 Reads

Digestive Diseases

Introduction: Postprocedural bleeding is a major adverse event after endoscopic resection of colorectal lesions, but the optimal surveillance time after endoscopy is unclear. In this study, we determined onset time and characteristics of postprocedural bleeding events. Methods: We retrospectively screened patients who underwent endoscopic resection of colorectal lesions at three German hospitals between 2010 and 2019 for postprocedural bleeding events using billing codes. Only patients who required re-endoscopy were included for analysis. For identified patients, we collected demographic data, clinical courses, characteristics of colorectal lesions, and procedure-related variables. Factors associated with late-onset bleeding were determined by univariate and multivariate logistic regression analysis. Results: From a total of 6,820 patients with eligible billing codes, we identified 113 cases with postprocedural bleeding after endoscopic mucosal (61.9%) or snare resection (38.1%) that required re-endoscopy. The median size of the culprit lesion was 20 mm (interquartile range 14-30 mm). The median onset time of postprocedural bleeding was day 3 (interquartile range: 1-6.5 days), with 48.7% of events occurring within 48 h. Multivariate logistic regression analysis demonstrates that a continued intake of antiplatelet drugs (OR: 3.98, 95% CI: 0.89-10.12, p = 0.025) and a flat morphology of the colorectal lesion (OR: 2.98, 95% CI: 1.08-8.01, p = 0.031) were associated with an increased risk for late postprocedural bleeding (>48 h), whereas intraprocedural bleeding was associated with a decreased risk (OR: 0.12, 95% CI: 0.04-0.50, p = 0.001). Conclusion: Significant postprocedural bleeding can occur up to 18 days after endoscopic resection of colorectal lesions, but was predominantly observed within 48 h. Continued intake of antiplatelet drugs and a flat polyp morphology are associated with risk for late postprocedural bleeding.


Endoskopisches Komplikationsmanagement am oberen und unteren GastrointestinaltraktEndoscopic management of complications of the upper and lower gastrointestinal tract

August 2023

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6 Reads

Die Gastroenterologie

Even when wide-ranging measures for avoidance of complications by improved techniques, training and many other activities are undertaken, postoperative and postinterventional complications still represent a daily problem in clinical medicine. The outcome of the patient is not uncommonly decided by the management of the complications. The failure to rescue or to control complications is increasingly recognized as being decisive for the success of treatment. This article therefore provides a current overview of the endoscopic management of complications of the upper and lower gastrointestinal tract. It describes when endoscopy can be used to detect or exclude a complication. The most important principles of treatment including the indications, limits of performance and technique are presented.




Citations (58)


... Another multicenter study found higher R0 resection rates in the TSA group (90.5% vs. 73.1%; p < 0.001) than in the EA group, even after additional ablation in the latter [14]. The study also reported a higher recurrence rate (16%) in the EA group than in the TSA group [14]. ...

Reference:

Endoscopic Management of Ampullary Adenomas: A Comprehensive Review
Endoscopic papillectomy versus surgical ampullectomy for adenomas and early cancers of the papilla: a retrospective Pancreas2000/European Pancreatic Club analysis
  • Citing Article
  • December 2024

Gut

... Nevertheless, the two groups differed significantly in stricture complexity, with the ICR group having statistically longer and more symptomatic strictures. Even if the majority of the strictures treated with ES in the published studies were located in the ileocolic anastomosis, ES was found to be feasible and safe also for refractory rectal anastomotic strictures [39]. ...

Endoscopic Stricturoplasty with Linear Stapler: An Efficient Alternative for the Refractory Rectal Anastomotic Stricture

Digestive Diseases and Sciences

... They can progress to ampullary adenocarcinomas, which make up about 0.5% of gastrointestinal neoplasms (Figures 4 and 5) [4]. Ampullary adenocarcinoma most commonly arises in an analogous fashion to colorectal cancer, following a well-documented adenoma-carcinoma sequence [2]. Patients with FAP have an autosomal dominant mutation in the adenomatous polyposis coli (APC) gene that predisposes them to developing numerous adenomas [7]. ...

Outcomes of rescue procedures in the management of locally recurrent ampullary tumors: A Pancreas 2000/EPC study
  • Citing Article
  • January 2023

Surgery

... However, in larger lesions, eFTR is associated with a substantial higher risk of R1/Rx resection (risk ratio 2.35 per 5 mm increase) and hence should be avoided [12]. Furthermore, there is an increased risk of secondary appendicitis following eFTR when the lesion is situated near the appendiceal orifice [13,14]. If the lesion is located near the appendiceal orifice, the lesion is larger than 15 mm or there is a suspicion of deep invasion, a colonoscopy-assisted laparoscopic wedge resection (CAL-WR) is an alternative treatment modality. ...

Adverse events of endoscopic full-thickness resection: results from the German and Dutch nationwide colorectal FTRD registry
  • Citing Article
  • November 2022

Gastrointestinal Endoscopy

... Furthermore, our study has demonstrated a shorter hospital stay after endoscopic treatment [13,20,21,23]. The prospect of reducing the length of hospital stays and post-treatment complications associated with the EA may lead to substantial and sustainable long-term cost savings. ...

Endoscopic papillectomy or pancreaticoduodenectomy for ampullary lesions: a single center retrospective cohort study
  • Citing Article
  • June 2022

Scandinavian Journal of Gastroenterology

... As a phosphatase, MTMR7 can exert its regulatory roles by affecting many protein kinases and transcription factors, such as RAS/ERK [11], peroxisome proliferator-activated receptor-gamma [12], and phosphoinositide 3-kinase/AKT [7]. ERK1/2 is a canonical Ser/Thr protein kinase and can be activated by phosphorylation to further phosphorylate other downstream substrates or transcription factors. ...

Expression of the EGFR-RAS Inhibitory Proteins DOK1 and MTMR7 and its Significance in Colorectal Adenoma and Adenoma Recurrence

Journal of gastrointestinal and liver diseases: JGLD

... Nevertheless, this kind of experience is much more common than ESD experience in the western world. Besides, previous animal studies have confirmed that the learning curve for TEM-ESD is steeper than for flexible ESD [37]. ...

Transanal endoscopic microsurgical submucosal dissection: Are there advantages over conventional ESD?
  • Citing Article
  • September 2021

... Among these factors, AL is a life-threatening complication with an incidence up to 20% [9,10]. Management of AL has improved in the last decade, with endoscopic negative pressure therapy (ENPT) emerging as an important approach to preserve the anastomosis and reduce the rate of permanent ostomy [7,11,12]. ...

Management of colorectal anastomotic leakage using endoscopic negative pressure therapy with or without protective ostomy: a retrospective study

International Journal of Colorectal Disease

... Enrolled patients were closely monitored until January 2024. The inclusion criteria were as follows: i) Having an LAGIST that was initially diagnosed as unsuitable for radical resection; and ii) being at risk of substantial organ dysfunction or borderline unresectable (3,(12)(13)(14). Following the administration of first-line therapy with imatinib, the included patients were followed for a median period of 41 months (range, 10 to 183 months). ...

Preservation of Organ Function in Locally Advanced Non-Metastatic Gastrointestinal Stromal Tumors (GIST) of the Stomach by Neoadjuvant Imatinib Therapy

... Recent studies have revisited earlier reservations regarding the use of EndoVAC in challenging scenarios such as intrathoracic leakage, conduit ischemia, mediastinitis, and systemic sepsis, suggesting its efficacy in reducing mortality rates and promoting successful outcomes [50,[53][54][55][56][57][58]. Advances in managing large, chronic cavities exceeding conventional size limits have also expanded its clinical applicability, with studies reporting clinical success rates exceeding 90% despite initial concerns [59][60][61]. ...

Endoscopic negative pressure therapy for leaks with large cavities in the upper gastrointestinal tract: is it a feasible therapeutic option?
  • Citing Article
  • December 2020

Scandinavian Journal of Gastroenterology