Oliver Beetz

Dr. Oliver Beetz


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 August 2018 in BMC Surgery
Verified
Journal Article
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OBOliver Beetz
Oliver Beetz
MKMichael Klein
Michael Klein
HSHarald Schrem
Harald Schrem
JGJill Gwiasda
Jill Gwiasda
FVFlorian Wolfgang Rudolf Vondran
Florian Wolfgang Rudolf Vondran
MKMoritz Kleine
Moritz Kleine
Distal cholangiocarcinoma (DCC) is a rare but over the last decade increasing malignancy and is associated with poor prognosis. According to the present knowledge curative surgery is the only chance for long term survival. This study was performed to evaluate prognostic factors for the outcome of patients undergoing curative surgery for distal cholangiocarcinoma. 75 patients who underwent surgery between January 2000 and December 2014 for DCC in curative intention were analysed retrospectively. Potential prognostic factors for survival were investigated including the extent of surgery using purposeful selection of covariates in multivariable Cox regression modeling. Preoperative biliary stenting (Hazard ratio (HR): 2.530; 95%-CI: 1.146–6.464, p = 0.020), the extent of surgery in case of positive histological venous invasion (HR: 1.209; 95%-CI: 1.017–1.410, p = 0.032), lymph node staging (HR: 2.183; 95%-CI: 1.250–3.841, p = 0.006), perineural invasion (HR: 2.118; 95%-CI: 1.147–4.054, p = 0.016) and postoperative complications graded in points according to Clavien-Dindo (HR: 1.395; 95%-CI: 1.148–1.699, p = 0.001) were indentified as independent significant risk factors for survival. Patients receiving preoperative biliary stenting showed prolonged duration between onset of symptoms and date of operation (p = 0.048). Preoperative biliary stenting reduces survival possibly due to delayed surgery. The extent of surgery is not an independent risk factor for survival except for patients with concomitant histological venous invasion. Oncological factors and postoperative surgical complications are independent prognostic factors for survival.

14 October 2020 in Pediatric Transplantation
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OBOliver Beetz
Oliver Beetz
CWClara A. Weigle
Clara A. Weigle
RNRabea Nogly
Rabea Nogly
JKJürgen Klempnauer
Jürgen Klempnauer
LPLars Pape
Lars Pape
FVFlorian Wolfgang Rudolf Vondran
Florian Wolfgang Rudolf Vondran
The field of pediatric kidney transplantation remains challenging due to an ongoing lack of size‐matched grafts and anatomical peculiarities. In the current study, we investigated the incidence of surgical complications in pediatric recipients, with a focus on risk factors and effects on graft outcome. We retrospectively reviewed all 2386 kidney transplantations at our institution from January 2005 until December 2018. Of these, 221 transplants were performed in pediatric recipients, defined as under the age of 18 years. Donor‐recipient body surface area ratios were calculated to evaluate the effects of size mismatching. Regression analyses were performed to identify independent risk factors for surgical complications and graft survival, respectively. Perioperative surgical complications requiring revision were observed in 34 (15.4%) cases. Leading cause for revision were vascular complications such as thrombosis or stenosis (n = 15 [6.8%]), which were significantly more frequent in case of young donors, (ie, donor age <6 years; OR: 4.281; CI‐95%:1.385‐13.226; P = .012), previous nephrectomy (OR: 3.407; CI‐95%:1.019‐11.387; P = .046), and en‐bloc grafts (OR: 4.923; CI‐95%:1.355‐17.884; P = .015), followed by postoperative hemorrhage (n = 10 [4.5%]), ureteral complications (n = 8 [3.6%]), and lymphoceles (n = 7 [3.2%]). Median follow‐up was 84.13 (0.92‐175.72) months. One‐, 5‐, and 10‐year graft survival rates were 97.1%, 88.9%, and 65.1%, respectively. Except for vascular complications (HR: 4.727; CI‐95%:1.363‐16.394; P = .014), none of the analyzed surgical morbidities significantly influenced graft survival. In conclusion, pediatric kidney transplantation achieves excellent long‐term results. However, meticulous surgical technique and continuous postoperative monitoring are imperative for early detection and treatment of imminent vascular complications, especially in case of young donors and en‐bloc grafts.

1 April 2022 in Surgical Infections
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Journal Article
Closed access
SCSebastian Cammann
Sebastian Cammann
SKSultan Karabulut
Sultan Karabulut
DDDaphne E. DeTemple
Daphne E. DeTemple
FOFelix Oldhafer
Felix Oldhafer
UKUlf Kulik
Ulf Kulik
OBOliver Beetz
Oliver Beetz
Background: Patients with extrahepatic cholangiocarcinoma (CCA) face considerable morbidity including septic complications after surgery. The aim of this study was to characterize the bacterial spectrum of the common hepatic duct (CHD) and its clinical relevance regarding morbidity and mortality after resection of extrahepatic CCA. Methods: We retrospectively analyzed data from 205 patients undergoing surgery for extrahepatic CCA in our department between January 2000 and March 2015. Patients were reviewed for pre-operative medical conditions, biliary bacterial flora obtained from intra-operative swabs, different septic complications, and post-operative outcome. Results: Bacterial colonization of the CHD was observed in 84.9% of the patients, with Enterococcus faecalis being detected most frequently (28.3%). Wound infections occurred in 30.7% of patients. Bacterial flora of the CHD and of the post-operatively colonized wounds coincided in 51.5% and of intra-abdominal swabs obtained during surgical revisions in 40.0%. Ciprofloxacin-resistant bacteria in the CHD were identified as independent risk factor for wound infections (odds ratio [OR], 3.330; 95% confidence interval [CI], 1.771–6.263; p < 0.001) and for complications requiring surgical revision (OR, 2.417; 95% CI, 1.288–4.539; p = 0.006). Most important independent risk factors for intra-hospital mortality were ampicillin-sulbactam-resistant bacteria in the CHD (OR, 3.969; 95% CI, 1.515–10.399; p = 0.005) and American Society of Anesthesiologists (ASA) grading >2 (OR, 2.936; 95% CI, 1.337–6.451; p = 0.007). Conclusions: Antibiotic-resistant bacteria from the CHD are associated with increased morbidity and mortality in patients undergoing resection for extrahepatic CCA.

22 August 2019 in PLOS ONE
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OBOliver Beetz
Oliver Beetz
JKJoline Kolb
Joline Kolb
BBBenjamin Buck
Benjamin Buck
BTBritta Trautewig
Britta Trautewig
KTKai Timrott
Kai Timrott
TLThorsten Lieke
Thorsten Lieke
Rejection of solid organ grafts is regarded to be dependent on T cell responses. Nonetheless, numerous studies have focused on the contribution of NK cells in this process, resulting in contradictory theories. While some conclude that there is no participation of NK cells, others found an inflammatory or regulative role of NK cells. However, the experimental settings are rarely comparable with regard to challenged species, strain combinations or the nature of the graft. Thus, clear definition of NK cell contribution might be impeded by these circumstances. In this study we performed heterotopic heart transplantation (HTx) in rats, choosing one donor-recipient-combination leading to a fast and a second leading to a prolonged course of graft rejection. We intervened in the rejection process, by depletion of recipient NK cells on the one hand and by injection of activated NK cells syngeneic to the recipients on the other. The fast course of rejection could not be influenced by any of the NK cell manipulative treatments. However, the more prolonged course of rejection was highly susceptible to depletion of NK cells, resulting in significant acceleration of rejection, while injection of NK cells induced acceptance of the grafts. We suggest that, depending on the specific setting, NK cells can attenuate the first trigger of immune response, which allows establishing the regulatory activity leading to tolerance of the graft.

19 August 2020 in Langenbeck's Archives of Surgery
Verified
Journal Article
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OBOliver Beetz
Oliver Beetz
CWClara A. Weigle
Clara A. Weigle
SCSebastian Cammann
Sebastian Cammann
FVFlorian W. R. Vondran
Florian W. R. Vondran
KTKai Timrott
Kai Timrott
FOFelix Oldhafer
Felix Oldhafer
Purpose: The incidence of intrahepatic cholangiocarcinoma is increasing worldwide. Despite advances in surgical and non-surgical treatment, reported outcomes are still poor and surgical resection remains to be the only chance for long-term survival of affected patients. The identification and validation of prognostic factors and scores, such as the recently introduced resection severity index, for postoperative morbidity and mortality are essential to facilitate optimal therapeutic regimens. Methods: This is a retrospective analysis of 269 patients undergoing resection of histologically confirmed intrahepatic cholangiocarcinoma between February 1996 and September 2018 at a tertiary referral center for hepatobiliary surgery. Regression analyses were performed to evaluate potential prognostic factors, including the resection severity index. Results: Median postoperative follow-up time was 22.93 (0.10–234.39) months. Severe postoperative complications (≥ Clavien-Dindo grade III) were observed in 94 (34.9%) patients. The body mass index (p = 0.035), the resection severity index (ASAT in U/l divided by Quick in % multiplied by the extent of liver resection graded in points; p = 0.006), additional hilar bile duct resection (p = 0.005), and number of packed red blood cells transfused during operation (p = 0.036) were independent risk factors for the onset of severe postoperative complications. Median Kaplan-Meier survival after resection was 27.63 months. Preoperative leukocytosis (p = 0.003), the resection severity index (p = 0.005), multivisceral resection (p = 0.001), and T stage ≥ 3 (p = 0.013) were identified as independent risk factors for survival. Conclusion: Preoperative leukocytosis and the resection severity index are useful variables for preoperative risk stratification since they were identified as significant predictors for postoperative morbidity and mortality, respectively.

1 August 2020 in ASAIO Journal
Verified
Journal Article
Closed access
OBOliver Beetz
Oliver Beetz
ABAnwar Bajunaid
Anwar Bajunaid
LMLuise Meißler
Luise Meißler
FVFlorian W. R. Vondran
Florian W. R. Vondran
MKMoritz Kleine
Moritz Kleine
KTKai Timrott
Kai Timrott
This study was performed to evaluate the incidence and outcome of patients with ventricular assist devices (VADs) undergoing abdominal surgery at our institution. A total of 604 adult patients who underwent VAD implantation between February 2004 and February 2018 were analyzed retrospectively with a median follow-up time of 66 (6-174) months. Thirty-nine patients (6.5%) underwent abdominal surgery. Elective surgical procedures were performed in 22 patients (56.4%), mainly for abdominal wall hernia repairs, partial colectomies, and cholecystectomies. Early after elective abdominal surgery no patient died, resulting in a median survival of 23 (1-78) months. Emergency surgery was performed in 17 patients (43.6%). The most common emergency indications were intestinal ischemia and/or perforation. Eight patients undergoing emergent surgery (44.4%) died within the first 30 days after primary abdominal operation, mainly due to sepsis and consecutive multiple organ failure, resulting in a dismal median survival of one month (0-52). Patients undergoing abdominal surgery had significantly lower rates of realized heart-transplantation (p= 0.031) and a significantly higher rate of VAD exchange, before or after abdominal surgery, due to thromboses or infections (p= 0.037). Nonetheless, overall survival after primary VAD implantation in these patients (median 38 months; 0-107) was not significantly impaired when compared to all other patients undergoing VAD implantation (median 30 months; 0-171). In summary, elective abdominal surgery can be performed safely when well planned by an experienced multidisciplinary team. Abdominal complications in VAD patients requiring emergent surgery, however, lead to a significant increase in short-term morbidity and a high 30-day mortality rate.