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Dive into the research topics where Karim A. Gawad is active.

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Featured researches published by Karim A. Gawad.


Annals of Surgery | 1996

In situ splitting of cadaveric livers. The ultimate expansion of a limited donor pool.

Xavier Rogiers; Massimo Malago; Karim A. Gawad; K.-W. Jauch; Michael Olausson; Wolfram T. Knoefel; Matthias Gundlach; Atef Bassas; Lutz Fischer; Martina Sterneck; Martin Burdelski; Christoph E. Broelsch

OBJECTIVE The authors evaluate the safety, applicability, and effectiveness of a new technique for split-liver transplantation. SUMMARY BACKGROUND DATA Split-liver transplantation offers an attractive way to increase the donor pool for cadaveric liver transplantation. The application of this concept has been hampered by inferior patient and graft survivals and higher complication rates. Without supportive data, the concern about increasing biliary leakage and poor initial graft function persisted. The authors focused on the causes of these complications by presenting a new technique to eliminate these problems. METHODS Liver splitting was performed in the heart-beating cadaveric organ donor, using the technique described for procurement of the left lateral lobe of a live donor. A detailed description of the technique is presented. A retrospective review of the first 14 transplantations resulting from 7 in situ splitting procedures was collected. The results were compared with 19 conventional split-liver transplants performed during the same period. RESULTS Six-month patient and graft survivals after in situ split-liver transplantation were 92.8% and 85.7%, respectively. Biliary complications were absent. Postoperative courses were mostly uneventful and characterized by lower peak transaminase levels compared with standard techniques. Early graft function of extrahepatic organs procured simultaneously was excellent. CONCLUSIONS In situ split-liver transplantation provides superior results, related mainly to reduction of cold ischemic damage of the grafts and avoidance of biliary complications. In situ split-liver transplantation renders graft reduction alone obsolete and opens a donor pool for adults to receive right lobes safely. It allows for long-distance sharing between pediatric and adult liver transplant units because the procedure abolishes ex situ benching and prolonged ischemia time and provides two anatomically perfect grafts with hemostasis accomplished.


Annals of Surgery | 2008

En bloc vascular resection for locally advanced pancreatic malignancies infiltrating major blood vessels: perioperative outcome and long-term survival in 136 patients.

Emre F. Yekebas; Dean Bogoevski; Guellue Cataldegirmen; Christina Kunze; Andreas Marx; Yogesh K. Vashist; Paulus G. Schurr; Lena Liebl; Sabrina Thieltges; Karim A. Gawad; Claus Schneider; Jakob R. Izbicki

Background:To assess in-hospital complication rates and survival duration after en bloc vascular resection (VR) for infiltration of pancreatic malignancies in major vessels. Methods:Between 1994 and 2005, 585 patients underwent potentially curative pancreatic resection without adjuvant chemotherapy. Four hundred forty-nine patients (77%) underwent standard oncologic resection (VR−), whereas 136 (23%) received VR (VR+). For calculation of in-hospital morbidity and mortality rates, all 136 patients who underwent VR were considered. In contrast, for survival analysis, only pancreatic adenocarcinoma patients (n = 100) were included. Results:One hundred twenty-eight VR+ patients underwent portal or superior mesenteric vein resection and 13 hepatic artery (HA) or superior mesenteric artery (SMA) resection. In 5 patients, synchronous VR addressing both the mesenterico-portal axis and either the HA or SMA was performed. In-hospital morbidity and mortality rates of VR− patients (39.7%/4.0%) nearly equaled that of VR+ patients (40.3%/3.7%). From the 100 patients with pancreatic adenocarcinoma, histopathology confirmed “true” vascular invasion in 77 patients. Twenty-three patients had peritumoral inflammation, mimicking tumor invasion. Median survival was 15 months (11.2–18.8) in patients with histopathologic proven vascular invasion and 16 months (14.0–17.9) in those without (P = 0.86). Two-year survival probabilities were 36% (without) versus 34% (with vascular invasion; P = 0.9). Among VR+ patients with histopathologically evidenced vascular invasion, 19 survived longer than 30 months, and 6 were still alive 5 years after surgery. Multivariate modeling identified nodal involvement (N1) and poor grading (G3) as the only predictors of decreased survival. Evidence of vascular invasion had no adverse impact on survival. Conclusion:Postoperative morbidity and mortality rates after en bloc VR are comparable with “standard” pancreatectomy procedures. Median survival of 15 months in patients with vascular invasion is superior to that of patients who undergo palliative therapy and nearly equals that of patients who are not in need for VR.


European Journal of Nuclear Medicine and Molecular Imaging | 2006

Prognostic relevance of FDG PET in patients with neurofibromatosis type-1 and malignant peripheral nerve sheath tumours

Winfried Brenner; Reinhard E. Friedrich; Karim A. Gawad; Christian Hagel; Andreas von Deimling; Maike de Wit; Ralph Buchert; Malte Clausen; Victor F. Mautner

PurposeIn patients with neurofibromatosis type-1 (NF1) and malignant peripheral nerve sheath tumours (MPNSTs), survival rates are low and time to death is often less than 2 years. However, there are patients with a more favourable prognosis who develop metastases rather late or not at all. Since histopathology and tumour grading are not well correlated with prognosis, we aimed to evaluate the potential of 18F-fluorodeoxyglucose positron emission tomography (FDG PET) for prediction of patient outcome in MPNST.MethodsFDG PET was performed in 16 patients with NF1 and MPNSTs. Standardised uptake values (SUVs) were calculated for each tumour and correlated to tumour grade and patient outcome in terms of survival or death.ResultsThree patients with tumour grade II had an SUV <3. None of these patients developed metastases or died during a follow-up of 41–62 months. Thirteen patients with tumour grades II and III had an SUV >3. Only one of these patients is still alive after 20 months; the remaining 12 died within 4–33 months. SUV predicted long-term survival with an accuracy of 94%, compared with 69% for tumour grade. In Kaplan-Meier survival analysis, patients with an SUV >3 had a significantly shorter mean survival time, 13 months, than patients with an SUV <3, in whom the mean survival time was 52 months. Tumour grading did not reveal differences in survival time (15 vs 12 months).ConclusionTumour SUV obtained by FDG PET was a significant parameter for prediction of survival in NF1 patients with MPNSTs while histopathological tumour grading did not predict outcome.


Annals of Surgical Oncology | 2007

Prognostic Implications of Netrin-1 Expression and Its Receptors in Patients with Adenocarcinoma of the Pancreas

Björn-Christian Link; Uta Reichelt; Matthias Schreiber; Jussuf T. Kaifi; Robin Wachowiak; Dean Bogoevski; Michael Bubenheim; Guel Cataldegirmen; Karim A. Gawad; Rana Issa; Susann Koops; Jakob R. Izbicki; Emre F. Yekebas

BackgroundTo assess the interaction between the expression of netrin-1 or of its receptors to the prognosis of ductal adenocarcinoma of the pancreas.MethodsIn 82 patients with resectable pancreatic adenocarcinoma who underwent curative operation, the expression patterns of netrin-1, deleted in colorectal carcinomas (DCC), UNC5H3, and neogenin were determined by immunohistochemical staining. Kaplan-Meier analysis was performed to assess the prognostic relevance of the examined expression patterns.ResultsMedian follow-up was 15 ± 19.9 months (range, 4–108 months). Patients suffering from tumors with no or little expression of netrin-1 (n = 67) had a median recurrence-free survival of 10 months (95% CI, 7–13 months), while a middle to strong expression (n = 15) was associated with a significantly worse median recurrence-free survival of only four months (95% CI, three to five months, p = 0.0165). Overall and recurrence-free survival showed no significant differences between the different expression patterns of DCC, UNC5H3 or neogenin. Netrin-1 expression had significant impact (p = 0.001) on overall survival of patients suffering from poorly differentiated tumors. Stratification according to the nodal status revealed significant influence (p = 0.007) of UNC5H3 expression on the overall survival of patients with pN1 status.ConclusionExpression of netrin-1 has significant impact on time to tumor relapse in adenocarcinoma of the pancreas. Netrin-1 expression is associated with worse outcome in poorly differentiated pancreatic adenocarcinomas. Risk-stratification according to the UNC5H3 receptor expression pattern shows that node positive patients (pN1) with no to little UNC5H3 expression carry a significantly worse prognosis than those with middle to strong UNC5H3 expression.


Journal of Oral Pathology & Medicine | 2008

Microsatellite GTn‐repeat polymorphism in the promoter of heme oxygenase‐1 gene is an independent predictor of tumor recurrence in male oral squamous cell carcinoma patients

Yogesh K. Vashist; Marco Blessmann; Florian Trump; Viacheslav Kalinin; Asad Kutup; Claus Schneider; Karim A. Gawad; Jussuf T. Kaifi; Rainer Schmelzle; Jakob R. Izbicki; Emre F. Yekebas

BACKGROUND Transcriptional activity of the heme oxygenase-1 gene (HMOX-1) is modulated by a GTn-repeat promoter polymorphism. The long GTn-repeat allele has been previously reported to be associated with increased risk of oral squamous cell carcinoma (OSCC) in male areca chewer and short GTn-repeat allele has been proposed to have protective properties in OSCC patients. The aim of the present study was to correlate the GTn-repeat genotypes with clinicopathological characteristics along with clinical outcome of non-areca chewer OSCC patients. METHODS DNA of 99 patients that underwent complete surgical resection of OSCC was analyzed for GTn-repeat polymorphism in the HMOX-1 promoter by polymerase chain reaction, capillary electrophoresis and DNA sequencing. RESULTS Seven SS (7.1%), 51 SL (51.5%) and 41 LL (41.4%) genotypes were found. In a total of 14 (14.1%) patients, tumor recurrence (TR) was observed. There was no TR in the SS allele carriers. In SL carriers three and in LL 11 TR occurred (P = 0.009, chi-squared test). Mean relapse-free survival was 109.2 months in SL allele carriers compared with 72.3 months in LL allele carriers (P = 0.01, log-rank test). Multivariate Cox regression modeling identified GTn-repeat genotype as an independent prognostic factor (P = 0.03; relative risk (RR) 4.1; 95% CI 1.1-14.6). CONCLUSION Presence of S allele was associated with a lower TR rate and better relapse-free survival in OSCC patients. HMOX-1 promoter polymorphism might be considered as a potential prognostic marker in OSCC patients.


Annals of Surgery | 2012

Ultrasonic dissection versus conventional dissection techniques in pancreatic surgery: a randomized multicentre study

Faik G. Uzunoglu; Anne Stehr; Judith Alexandra Fink; Eik Vettorazzi; Alexandra M. Koenig; Karim A. Gawad; Yogesh K. Vashist; Asad Kutup; Oliver Mann; Francesca Gavazzi; Alessandro Zerbi; Claudio Bassi; Christos Dervenis; Marco Montorsi; Maximilian Bockhorn; Jakob R. Izbicki

Objective:This prospective randomized multicenter trial was performed to assess the potential benefits of ultrasonic energy dissection compared with conventional dissection techniques in pancreatic surgery. Background:Surgical procedures for tumors of the pancreatic head involve time-consuming manual dissection. The primary hypothesis was that use of ultrasonic tissue and vessel dissection would lead to substantial saving in operative time during pancreatic resection. Methods:Patients eligible for pancreaticoduodenectomy (PD) or pylorus-preserving PD (PPPD) were randomized to group A (dissection with ultrasonic device) or group B (conventional dissection) from March 2009 to May 2011. The primary endpoint was overall duration of operation time. Secondary endpoints were time to end of resection phase, intraoperative blood loss, number of transfused units of blood, and postoperative morbidity. Results:Analysis of primary and secondary endpoints included 101 patients, who received either PD or PPPD. Demographical characteristics and clinical parameters were similar in both groups. The use of an ultrasonic dissection device did not significantly reduce overall operation time (median 316 minutes in group A and 319 minutes in group B, P = 0.95) and did not significantly increase the costs of surgery. Analysis of secondary endpoints revealed no difference in postoperative course. Conclusions:Tissue dissection and vessel closure using an ultrasonic device is equivalent to dissection with conventional techniques in pancreatic surgery.


Journal of Medical Case Reports | 2009

Perivascular epitheloid cell tumour (PEComa) of the retroperitoneum – a rare tumor with uncertain malignant behaviour: a case report

Alexandra M. Koenig; Alexander Quaas; Thorsten Ries; Emre F. Yekebas; Karim A. Gawad; Yogesh K. Vashist; Christoph Burdelski; Oliver Mann; Jakob R. Izbicki; Andreas Erbersdobler

IntroductionPerivascular epitheloid cell tumours are rare mesenchymal neoplasms characterized by a proliferation of perivascular cells with an epitheloid phenotype and expression of myomelanocytic markers.Case presentationHere we present the case of a cystic perivascular epitheloid cell tumour of the retroperitoneum associated with multifocal lung lesions. A 27-year-old woman underwent laparotomy to remove a 10 × 6 × 4 cm sized retroperitoneal mass. The resected specimen was subjected to frozen and permanent histological sections with conventional and immunohistochemical stains, including antibodies against HMB45. The tumour displayed the typical morphological and immunohistochemical features of a perivascular epitheloid cell tumour. Focal necrosis and a proliferative index of 10% suggested a malignant potential. Moreover, postoperative computed tomography scans demonstrated multiple lung lesions, which were radiologically interpreted as being most likely compatible with lymphangioleiomyomatosis.ConclusionSince lymphangioleiomyomatosis, an otherwise benign condition, belongs to the family of perivascular epitheloid cell tumours, it cannot be excluded that the lung lesions in this case in fact represent metastases from the retroperitoneal perivascular epitheloid cell tumour rather than independent neoplasms. More experience with this new and unusual tumour entity is clearly needed in order to define reliable criteria for benign or malignant behaviour.


BMC Infectious Diseases | 2009

Abscess of adrenal gland caused by disseminated subacute Nocardia farcinica pneumonia. A case report and mini-review of the literature

Michael Tachezy; Philipp Simon; Corina Ilchmann; Yogesh K. Vashist; Jakob R. Izbicki; Karim A. Gawad

BackgroundInfections caused by Nocardia farcinica are uncommon and show a great variety of clinical manifestations in immunocompetent and immunocompromised patients. Because of its unspecific symptoms and tendency to disseminate it may mimic the clinical symptoms and radiologic findings of a tumour disease and the diagnosis of nocardiosis can easily be missed, because there are no characteristic symptoms.Case presentationWe present a case of an adrenal gland abscess caused by subacute disseminated N. farcinica pneumonia.ConclusionAn infection with N. farcinica is potentially lethal because of its tendency to disseminate -particularly in the brain- and its high resistance to antibiotics. Awareness of this differential diagnosis allows early and appropriate treatment to be administered.


Surgical Endoscopy and Other Interventional Techniques | 2003

Ambulatory long-term pH monitoring in pigs

Karim A. Gawad; R. Wachowiak; C. Rempf; W. J. Tiefenbacher; Tim Strate; E. Achilles; C. Blöchle; J. R. Izbicki

Background: pH monitoring has been established as the “gold standard” in the diagnosis of gastroesophageal reflux. Evaluation of experimental antireflux therapy should therefore also include this technique, but a suitable technique in an experimental model did not exist so far. The aim of our study was to establish a reliable method for the evaluation of an experimental reflux model in pigs. Methods: A total of 33 German Landrace pigs with an average body weight of 56 (50.2–67.2) kg were included. pH monitoring was performed before and after open cardiomyotomy in each animal. All manipulations were performed under general anesthesia. After manometric localization of the gastroesophageal high-pressure zone, a standard pH probe was inserted into the pharynx through a small needle-punctured canal on the side of the animal’s snout and placed under endoscopic guidance with the proximal sensor 3 cm above the lower esophageal sphincter (LES) and the distal sensor in the stomach for reference. The harness to carry the pH recorder on the animal’s back consisted of a modified belly strap that enabled the animal to move around without limitation. For analysis the same threshold levels were defined as in humans. Gastroesophageal reflux was induced by cardiomyotomy. Results: The placement of the standard pH probe was possible in all cases. Inserting the probe on the side of the snout left the animals free to nuzzle, which complies with the normal habits of pigs, without breaking the probes and without being compromised in their natural behavior. Repeated punctures for multiple measurements were easily feasible. We performed up to three examinations in each individual animal. Recording was performed for 48 h. A mean number of 67.3 (±9.7) acidic refluxes were registered. The mean number of long acidic refluxes was 3.2 (±0.75). For an average total time of 75.5 (±14.3) min the pH was below 4 accounting for a fraction time pH below 4 of 3.5% (±0.68%). Following cardiomyotomy the number of acidic refluxes increased significantly to 166.1 (±21.8) and the number of long refluxes to 17.74 (±3.35). The total time of pH below 4 increased to 371.3 (±62) min so that the fraction time pH below 4 was 14.5% (p = 0.0006). Conclusion: pH monitoring should be mandatory in any investigation of antireflux therapy. Our method is easy and secure to perform. It is suitable for other gastrointestinal investigations (Bilitec, long-term manometry) that could be carried out using the same technique. The described data represent the basis for other investigations of experimental antireflux therapy.


Journal of Gastrointestinal Surgery | 2013

LigaSure™ vs. conventional dissection techniques in pancreatic surgery--a prospective randomised single-centre trial.

Faik G. Uzunoglu; Maximilian Bockhorn; Judith Alexandra Fink; Matthias Reeh; Eik Vettorazzi; Karim A. Gawad; Dean Bogoevski; Yogesh K. Vashist; Tung Yu Tsui; Alexandra M. Koenig; Oliver Mann; Jakob R. Izbicki

BackgroundSurgical procedures in pancreatic surgery are well established, but still involve time-consuming manual dissection. We compared the use of LigaSure with conventional dissection techniques in pancreatic surgery in a prospective randomised single-centre trial (registration number: NCT00850291).MethodsPatients with tumours of the pancreatic head that were assumed to be technically resectable were randomised to LigaSure or conventional surgery. The primary endpoint of this study was overall operation time. Secondary endpoints were preparation time until tumour resection, intraoperative blood loss, number of given units of packed red blood cells, costs of surgery, postoperative morbidity, length of hospital stay and mortality.ResultsThere was no difference in overall operation time between the two groups (P = 0.227). Median costs for pancreatic surgery were significantly less in the conventional group with €3,047 (range 2,004–5,543) vs. €3,527 (range 2,516–5,056, P = 0.009). Preparation time, intraoperative blood loss, number of units of packed red blood cells, postoperative morbidity, length of hospital stay and mortality did not differ between the two groups.ConclusionOur data indicate that the LigaSure device is equivalent to conventional dissection modalities in pancreatic surgery.

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