@article{KelmGermerSchlegeletal.2021,
  author    = {Kelm, Matthias and Germer, Christoph-Thomas and Schlegel, Nicolas and Flemming, Sven},
  title     = {The revival of surgery in Crohn's disease — early intestinal resection as a reasonable alternative in localized ileitis},
  series = {Biomedicines},
  volume    = {9},
  journal   = {Biomedicines},
  number    = {10},
  issn      = {2227-9059},
  doi       = {10.3390/biomedicines9101317},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246296},
  year      = {2021},
  abstract  = {Crohn's disease (CD) represents a heterogeneous and complex disease with no curative therapeutic option available to date. Current therapy is mainly antibody-based focusing on the immune system while other treatment alternatives such as surgery are considered to be "last options". However, medical therapy for CD results in mild to severe side effects in a relevant amount of patients and some patients do not respond to the medication. Following that, quality of life is often significantly reduced in this patient cohort, thus, therapeutic alternatives are urgently needed. Updated evidence has revealed that surgery such as ileocecal resection (ICR) might be a potential therapeutic option in case of localized terminal ileitis since resection at early time points improves quality of life and significantly reduces the postoperative need for immunosuppressive medication with low rates of morbidity. In addition, new surgical approaches such as Kono-S anastomosis or inclusion of the mesentery result in significantly reduced rates of disease recurrence and reoperation. Based on the new evidence, the goal of this review is to provide an update on the role of surgery as a reasonable alternative to medical therapy in the interdisciplinary treatment of patients with CD.},
  language  = {en}
}
@article{FlemmingHankirKusanetal.2021,
  author    = {Flemming, Sven and Hankir, Mohammed K. and Kusan, Simon and Krone, Manuel and Anger, Friedrich and Germer, Christoph-Thomas and Wiegering, Armin},
  title     = {Safety of elective abdominal and vascular surgery during the COVID-19 pandemic: a retrospective single-center study},
  series = {European Journal of Medical Research},
  volume    = {26},
  journal   = {European Journal of Medical Research},
  doi       = {10.1186/s40001-021-00583-x},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264975},
  year      = {2021},
  abstract  = {Background Patients with coronavirus disease 2019 (COVID-19) who undergo surgery have impaired postoperative outcomes and increased mortality. Consequently, elective and semi-urgent operations on the increasing number of patients severely affected by COVID-19 have been indefinitely postponed.in many countries with unclear implications on disease progression and overall survival. The purpose of this study was to evaluate whether the establishment of a standardized screening program for acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is sufficient to ensure high-quality medical and surgical treatment of COVID-19 and non-COVID-19 patients while minimizing in-hospital SARS-CoV-2 transmission. Methods The screening program comprised polymerase chain reaction (PCR) testing of nasopharyngeal swabs and a standardized questionnaire about potential symptoms for SARS-CoV-2 infection. All elective and emergency patients admitted to the surgical department of a tertiary-care hospital center in Lower Franconia, Germany, between March and May 2020 were included and their characteristics were recorded. Results Out of the study population (n = 657), 509 patients (77.5\%) had at least one risk factor for a potentially severe course of COVID-19 and 164 patients (25\%) were active smokers. The average 7-day incidence in Lower Franconia was 24.0/100,000 during the observation period. Preoperative PCR testing revealed four asymptomatic positive patients out of the 657 tested patients. No postoperative SARS-CoV-2 infection or transmission could be detected. Conclusion The implementation of a standardized preoperative screening program to both COVID-19 and non-COVID-19 patients can ensure high-quality surgical care while minimizing infection risk for healthcare workers and potential in-hospital transmission.},
  language  = {en}
}
@article{MeirKannapinDiefenbacheretal.2021,
  author    = {Meir, Michael and Kannapin, Felix and Diefenbacher, Markus and Ghoreishi, Yalda and Kollmann, Catherine and Flemming, Sven and Germer, Christoph-Thomas and Waschke, Jens and Leven, Patrick and Schneider, Reiner and Wehner, Sven and Burkard, Natalie and Schlegel, Nicolas},
  title     = {Intestinal epithelial barrier maturation by enteric glial cells is GDNF-dependent},
  series = {International Journal of Molecular Sciences},
  volume    = {22},
  journal   = {International Journal of Molecular Sciences},
  number    = {4},
  issn      = {1422-0067},
  doi       = {10.3390/ijms22041887},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258913},
  year      = {2021},
  abstract  = {Enteric glial cells (EGCs) of the enteric nervous system are critically involved in the maintenance of intestinal epithelial barrier function (IEB). The underlying mechanisms remain undefined. Glial cell line-derived neurotrophic factor (GDNF) contributes to IEB maturation and may therefore be the predominant mediator of this process by EGCs. Using GFAP\(^{cre}\) x Ai14\(^{floxed}\) mice to isolate EGCs by Fluorescence-activated cell sorting (FACS), we confirmed that they synthesize GDNF in vivo as well as in primary cultures demonstrating that EGCs are a rich source of GDNF in vivo and in vitro. Co-culture of EGCs with Caco2 cells resulted in IEB maturation which was abrogated when GDNF was either depleted from EGC supernatants, or knocked down in EGCs or when the GDNF receptor RET was blocked. Further, TNFα-induced loss of IEB function in Caco2 cells and in organoids was attenuated by EGC supernatants or by recombinant GDNF. These barrier-protective effects were blunted when using supernatants from GDNF-deficient EGCs or by RET receptor blockade. Together, our data show that EGCs produce GDNF to maintain IEB function in vitro through the RET receptor.},
  language  = {en}
}
@article{KelmAngerEichlingeretal.2021,
  author    = {Kelm, Matthias and Anger, Friedrich and Eichlinger, Robin and Brand, Markus and Kim, Mia and Reibetanz, Joachim and Krajinovic, Katica and Germer, Christoph-Thomas and Schlegel, Nicolas and Flemming, Sven},
  title     = {Early Ileocecal Resection Is an Effective Therapy in Isolated Crohn's Disease},
  series = {Journal of Clinical Medicine},
  volume    = {10},
  journal   = {Journal of Clinical Medicine},
  number    = {4},
  issn      = {2077-0383},
  doi       = {10.3390/jcm10040731},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228822},
  year      = {2021},
  abstract  = {Despite the increasing incidence and prevalence of Crohn's Disease (CD), no curative options exist and treatment remains complex. While therapy has mainly focused on medical approaches in the past, growing evidence reveals that in cases of limited inflammation, surgery can suffice as an alternative primary treatment. We retrospectively assessed the disease course and outcomes of 103 patients with terminal Ileitis who underwent primary surgery (n = 29) or received primary medical treatment followed by surgery (n = 74). Primary endpoint was the need for immunosuppressive medication after surgical treatment (ileocecal resection, ICR) during a two-years follow-up. Rates for laparoscopic ICR were enhanced in case of early surgery, but no differences were seen for postoperative complications. In case of immunosuppressive medication, patients with ICR at an early state of disease needed significantly less anti-inflammatory medication during the two-year postoperative follow-up compared to patients who were primarily treated medically. Furthermore, in a subgroup analysis for patients with localized ileocecal disease manifestation, early surgery consistently resulted in a decreased amount of medical therapy postoperatively. In conclusion primary ICR is safe and effective in patients with limited CD, and the need for immunosuppressive medication during the postoperative follow-up is low compared to patients receiving surgery at a later stage of disease.},
  language  = {en}
}
@article{BrandReimerReibetanzetal.2021,
  author    = {Brand, Markus and Reimer, Stanislaus and Reibetanz, Joachim and Flemming, Sven and Kornmann, Marko and Meining, Alexander},
  title     = {Endoscopic full thickness resection vs. transanal endoscopic microsurgery for local treatment of rectal neuroendocrine tumors - a retrospective analysis},
  series = {International Journal of Colorectal Disease},
  volume    = {36},
  journal   = {International Journal of Colorectal Disease},
  issn      = {0179-1958},
  doi       = {10.1007/s00384-020-03800-x},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234833},
  pages     = {971-976},
  year      = {2021},
  abstract  = {Purpose Local treatment of small well-differentiated rectal neuroendocrine tumors (NETs) is recommended by current guidelines. However, although several endoscopic methods have been established, the highest R0 rate is achieved by transanal endoscopic microsurgery (TEM). Since a recently published study about endoscopic full thickness resection (eFTR) showed a R0 resection rate of 100\%, the aim of this study was to evaluate both methods (eFTR vs. TEM). Methods We retrospectively analyzed all patients with rectal NET treated either by TEM (1999-2018) or eFTR (2016-2019) in two tertiary centers (University Hospital Wuerzburg and Ulm). We analyzed clinical, procedural, and histopathological outcomes in both groups. Results Twenty-eight patients with rectal NET received local treatment (TEM: 13; eFTR: 15). Most tumors were at stage T1a and grade G1 or G2 (in the TEM group two G3 NETs were staged T2 after neoadjuvant chemotherapy). In both groups, similar outcomes for en bloc resection rate, R0 resection rate, tumor size, or specimen size were found. No procedural adverse events were noted. Mean procedure time in the TEM group was 48.9 min and 19.2 min in the eFTR group. Conclusion eFTR is a convincing method for local treatment of small rectal NETs combining high safety and efficacy with short interventional time.},
  language  = {en}
}