Sandra Schipper

Dr. Sandra Schipper


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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26 October 2021 in Surgical Endoscopy
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Sophia M. SchmitzSophia M. Schmitz
Sophia M. Schmitz
PAPatrick H. Alizai
Patrick H. Alizai
AKAndreas Kroh
Andreas Kroh
SSSandra Schipper
Sandra Schipper
JBJonathan Frederik Brozat
Jonathan Frederik Brozat
TUTom F. Ulmer
Tom F. Ulmer
Background: Bariatric surgery in super-super-obese (SSO) patients remains a continuous challenge due to intraabdominal fat masses, higher liver volume and existing comorbidities. A convenient procedure in SSO patients is one anastomosis gastric bypass (OAGB). The aim of this study was to compare the outcome of SSO patients undergoing OAGB in comparison to laparoscopic sleeve gastrectomy (LSG). Methods: We retrospectively reviewed data from SSO patients who underwent OAGB and LSG in our institution between 2008 and 2020. Primary endpoints included percentage total body weight loss and percentage BMI loss at 12, 24, and 36 months after the operation. Secondary endpoints were perioperative complications, procedure length, length of hospital stay and outcome of comorbidities. Results: 243 patients were included in this study. 93 patients underwent LSG and 150 underwent OAGB. At any of the time points evaluated, weight loss in patients after OAGB was greater than in LSG patients, while procedure length was significantly shorter for OAGB than LSG (81.4 vs. 92.1 min, p-value < 0.001). Additionally, mean length of hospital stay was shorter in the OAGB group (3.4 vs. 4.5 days, p-value < 0.001). There were more severe complications (Clavien-Dindo ≥ 3a) in the LSG group (11.8% vs 2.7%, p-value = 0.005). Conclusion: In this retrospective analysis, OAGB was superior to LSG in terms of weight loss in SSO patients. Procedure length and hospital stay were shorter after OAGB in comparison to LSG and there were fewer severe complications. OAGB can therefore be regarded a safe and effective treatment modality for SSO patients.

26 October 2020 in Journal of Clinical Medicine
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KRKarl Peter Rheinwalt
Karl Peter Rheinwalt
UDUta Drebber
Uta Drebber
RSRobert Schierwagen
Robert Schierwagen
SKSabine Klein
Sabine Klein
UNUlf Peter Neumann
Ulf Peter Neumann
MBMaximilian Joseph Brol
Maximilian Joseph Brol
Background. Bariatric surgery is a widely used treatment for morbid obesity. Prediction of postoperative weight loss currently relies on prediction models, which mostly overestimate patients’ weight loss. Data about the influence of Non-alcoholic fatty liver disease (NAFLD) on early postoperative weight loss are scarce. Methods. This prospective, single-center cohort study included 143 patients receiving laparoscopic gastric bypass surgery (One Anastomosis-Mini Gastric Bypass (OAGB-MGB) or Roux-en-Y Gastric Bypass (RYGB)). Liver biopsies were acquired at surgery. NAFLD activity score (NAS) assigned patients to “No NAFLD”, “NAFL” or “NASH”. Follow up data were collected at 3, 6 and 12 months. Results. In total, 49.7% of patients had NASH, while 41.3% had NAFL. Compared with the No NAFLD group, NAFL and NASH showed higher body-mass-index (BMI) at follow-up (6 months: 31.0 kg/m2 vs. 36.8 kg/m2 and 36.1 kg/m2, 12 months: 27.0 kg/m2 vs. 34.4 and 32.8 kg/m2) and lower percentage of total body weight loss (%TBWL): (6 months: 27.1% vs. 23.3% and 24.4%; 12 months: 38.5% vs. 30.1 and 32.6%). Linear regression of NAS points significantly predicts percentage of excessive weight loss (%EWL) after 6 months (Cologne-weight-loss-prediction-score). Conclusions. Histopathological presence of NAFLD might lead to inferior postoperative weight reduction after gastric bypass surgery. The mechanisms underlying this observation should be further studied.

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Sophia M. SchmitzSophia M. Schmitz
Sophia M. Schmitz
HDHenriette Dohmeier
Henriette Dohmeier
CSChristian Stoppe
Christian Stoppe
PAPatrick H. Alizai
Patrick H. Alizai
SSSandra Schipper
Sandra Schipper
TUTom F. Ulmer
Tom F. Ulmer
Organoprotective effects of noble gases are subject of current research. One important field of interest is the effect of noble gases on hepatic regenerative capacity. For the noble gas argon, promising studies demonstrated remarkable experimental effects in neuronal and renal cells. The aim of this study was to investigate the effects of argon on the regenerative capacity of the liver after ischemia/reperfusion injury (IRI). Male, Sprague-Dawley rats underwent hepatic IRI by clamping of the hepatic artery. Expression of hepatoproliferative genes (HGF, IL-1β, IL-6, TNF), cell cycle markers (BrdU, TUNEL, Ki-67), and liver enzymes (ALT, AST, Bilirubin, LDH) were assessed 3, 36, and 96 h after IRI. Expression of IL-1β and IL-6 was significantly higher after argon inhalation after 36 h (IL-1β 5.0 vs. 8.7 fold, p = 0.001; IL-6 9.6 vs. 19.1 fold, p = 0.05). Ki-67 was higher in the control group compared to the argon group after 36 h (214.0 vs. 38.7 positive cells/1000 hepatocytes, p = 0.045). Serum levels of AST and ALT did not differ significantly between groups. Our data indicate that argon inhalation has detrimental effects on liver regeneration after IRI as measured by elevated levels of the proinflammatory cytokines IL-1β and IL-6 after 36 h. In line with these results, Ki-67 is decreased in the argon group, indicating a negative effect on liver regeneration in argon inhalation.

31 May 2023 in Biomedicines
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Sophia M. SchmitzSophia M. Schmitz
Sophia M. Schmitz
SSSebastian Storms
Sebastian Storms
AKAlexander Koch
Alexander Koch
CSChristine Stier
Christine Stier
AKAndreas Kroh
Andreas Kroh
PAPatrick H. Alizai
Patrick H. Alizai
(1) Background: Metabolically healthy obesity (MHO) is a concept that applies to obese patients without any elements of metabolic syndrome (metS). In turn, metabolically unhealthy obesity (MUO) defines the presence of elements of metS in obese patients. The components of MUO can be divided into subgroups regarding the elements of inflammation, lipid and glucose metabolism and cardiovascular disease. MUO patients appear to be at greater risk of developing non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) compared to MHO patients. The aim of this study was to evaluate the influence of different MUO components on NAFLD and NASH in patients with morbid obesity undergoing bariatric surgery. (2) Methods: 141 patients undergoing bariatric surgery from September 2015 and October 2021 at RWTH Aachen university hospital (Germany) were included. Patients were evaluated pre-operatively for characteristics of metS and MUO (HbA1c, HOMA, CRP, BMI, fasting glucose, LDL, TG, HDL and the presence of arterial hypertension). Intraoperatively, a liver biopsy was taken from the left liver lobe and evaluated for the presence of NAFLD or NASH. In ordinal regression analyses, different factors were evaluated for their influence on NAFLD and NASH. (3) Results: Mean BMI of the patients was 52.3 kg/m2 (36–74.8, SD 8.4). Together, the parameters HbA1c, HOMA, CRP, BMI, fasting glucose, LDL, TG, HDL and the presence of arterial hypertension accounted for a significant amount of variance in the outcome, with a likelihood ratio of χ2 (9) = 41.547, p < 0.001, for predicting the presence of NASH. Only HOMA was an independent predictor of NASH (B = 0.102, SE = 0.0373, p = 0.007). Evaluation of steatosis showed a similar trend (likelihood ratio χ2 (9) = 40.272, p < 0.001). Independent predictors of steatosis were HbA1c (B = 0.833, SE = 0.343, p = 0.015) and HOMA (B = 0.136, SE = 0.039, p < 0.001). (4) Conclusions: The above-mentioned model, including components of MUO, was significant for diagnosing NASH in patients with morbid obesity undergoing bariatric surgery. Out of the different subitems, HOMA independently predicted the presence of NASH and steatosis, while HbA1c independently predicted steatosis and fibrosis. Taken together, the parameter of glucose metabolism appears to be more accurate for the prediction of NASH than the parameters of lipid metabolism, inflammation or the presence of cardiovascular disease.

12 April 2020 in Journal of Clinical Medicine
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SSSandra Schipper
Sandra Schipper
MZMarkus Zimmermann
Markus Zimmermann
AKAndreas Kroh
Andreas Kroh
UNUlf Peter Neumann
Ulf Peter Neumann
TUTom Florian Ulmer
Tom Florian Ulmer
Background and Methods: Tumors infiltrating the inferior caval vein (ICV) have been considered irresectable in the past due to high perioperative risks. Consequently, the only treatment option for these patients was best supportive care, which resulted in reduced survival. Advancements in surgical techniques have since evolved, such that combined resections of the ICV and the hepatic malignancy are being performed. The aim of this study was the evaluation of the long-term outcomes (e.g., survival) and short-term risks of this procedure. In this single-center, retrospective cohort study (n = 24), we evaluated surgical and oncological outcome for patients undergoing hepatic surgery for oncological indications in combination with resections of the ICV. In addition, we investigated which factors are associated with survival. Results: First, we showed that perioperative mortality is as low as 4.1%. Second, we showed that perioperative co-morbidities are acceptable for this type of advanced hepatobiliary surgery. Third, the reconstruction of the ICV by means of a patch was superior in terms of survival compared to other types of reconstructions. This finding was independent of the type or the aggressiveness of tumor or the resections status. Discussion: In our cohort, many patients had undergone (multiple) preceding visceral surgical interventions or underwent multi-visceral surgery. Despite the medical complexity, survival was encouraging in this cohort, offering novel treatment modalities with a low risk of severe morbidities.