Patrick Günther

Role of MRI in the management of patients with nephroblastoma

Magnetic resonance imaging (MRI) presents the main diagnostic tool for differentiation and staging of renal tumors in childhood. Nephroblastoma is the most common malignant tumor in children. Radiological findings play an important role in therapy study trials of SIOP (International Society of Pediatric Oncology), especially for indicating preoperative chemotherapy. In the past few years MRI has gained great importance in imaging of nephroblastoma and has replaced computed tomography (CT). The aim of this review is to present the diagnostic possibilities of MRI in relation to the requirements of therapy studies. For nephroblastoma, MRI provides important information about tumor extent and distant metastasis. A special focus of MRI in distant staging is venous extent of the tumor into the inferior vena cava. In addition, MRI has an important role in monitoring chemotherapy and in preoperative planning by volume rendering and three-dimensional postprocessing.

Significance of image-defined risk factors for surgical complications in patients with abdominal neuroblastoma.

INTRODUCTION Neuroblastoma (NB) is one of the most common malignant tumors in infancy. The commonly used International Neuroblastoma Staging System is not suitable for determining the surgical risks. To address this, we aimed to evaluate the correlation between so-called image-defined risk factors (IDRFs) and the surgical risks in abdominal neuroblastoma. MATERIAL AND METHODS We evaluated 60 cases who underwent surgical intervention and examined the pre-surgical radiological imaging to look for IDRFs and surgical complications in children with abdominal neuroblastoma. RESULTS The MRI- and CT-scans showed a total of 122 IDRFs in 39 cases. Complete resection was carried out in 50%, partial excision in 32%, and biopsy in 18% of cases. Total resection was possible in 100% of cases with no IDRF. Where IDRFs were present, total resection was only possible in 26% of cases (p<0.0001). We found a highly significant, negative correlation between the number of IDRFs and the possibility of performing complete resection of NB (p<0.0001). 7 (11.6%) complications were detected, all in patients who showed at least one IDRF previously. CONCLUSION Our findings indicate that IDRFs are useful indicators for predicting surgical risk and surgical outcome and thus should be taken into account when planning surgery.

13-cis retinoic acid treatment of a patient with chemotherapy refractory nephroblastomatosis

A 9-month-old girl presented with massive bilateral diffuse nephroblastomatosis. After response to actinomycin D and vincristine over a period of 1 year, the nephroblastomatosis continuously progressed under this treatment. As retinoic acid signaling is critical for normal renal development and nephroblastomatosis seems histologically as undifferentiated embryonal tissue, we added 13-cis retinoic acid to the chemotherapy regimen. Three months thereafter, kidney volumes declined significantly over a period of 1 year. Interestingly, nephroblastomatosis-associated acquired von Willebrand disease also resolved. Retinoic acid maybe a novel nontoxic treatment option for nephroblastomatosis requiring further systematic evaluation.

Intracorporal suturing—driving license necessary?

BACKGROUND Intracorporeal suturing and knot tying (ICKT) in minimal invasive surgery (MIS) represents a key skill for advanced procedures. Different methods exist for measuring knot quality and performance, but the heterogeneity of these methods makes direct comparisons difficult. The aim of this study is to compare the quality of a laparoscopic knot to one that is performed open. METHODS To compare open and laparoscopic knot-tying methods we used a surgeons square knot. For laparoscopic knot tying we used a Pelvitrainer. The 32 participants were divided among 4 groups of different skill levels. Group 1 consisted of 6 senior physicians. Group 2 was made up of 10 first to fourth year interns. Groups 3 and 4 contained 16 medical students who had never performed either laparoscopic procedures or open sutures before. Group 3 participants received a 1-hour hands-on training in suturing, whereas group 4 participants received no prior training. Total time, knot quality, suture placement accuracy, and performance defined the parameters for assessment in this study. RESULTS All participants, irrespective of education level were inferior in ICKT compared to open suturing. Only Group 1 showed no significant difference in knot quality and accuracy between the open and laparoscopic suture performance. CONCLUSION It is well documented that psychomotor skills need to be developed before more advanced skills can be put into practice. Training centres for minimally invasive surgery should be an integral part of surgical education. The variables in our study are meaningful and easy to implement. They can be used to measure personal progress and as objective parameters in the development of laparoscopic trainee education.

Surgical complications in abdominal tumor surgery in children. Experiences at a single oncological center.

INTRODUCTION Surgical complications after tumor operations are frequent in children, with rates of up to 30% cited in the literature. Various approaches to reduce these complication rates have been attempted, with preoperative chemotherapy holding pride of place. One approach to minimize surgical complications is better preoperative preparation. In a retrospective analysis, we evaluated the complications associated with tumor surgery. MATERIAL AND METHODS We retrospectively analyzed patient data from 1991 to 2007. The distribution of the various tumors, the type of surgery, and complications were evaluated. For neuroblastomas a differentiated analysis of complications was performed, which included staging and radiologically defined surgical risk factors (SRFs). Patients were divided into two groups: A and B. Intensified surgical planning with 3D visualization was used in patients of group B. RESULTS A total of 145 operations for abdominal tumors were performed in 123 patients. The three most common diseases were neuroblastoma (36%), nephroblastoma (26%), and ovarian tumor (19%). In 68% of patients complete resection and in 19% of cases partial resection of the tumor was carried out; open biopsy was performed in 13%. A total of 15 (10.3%) complications developed: the incidence of complications for group A was 11.8% and 7.7% for group B (p=0.5). For nephroblastoma these figures were 27.9% and 21.2% (p=1.0). In the group of patients with neuroblastoma, six complications developed in patients from group A (21.4%) and one in a group B patient (4.2%) (p=0.107). 54% of neuroblastomas were completely and 33% partially resected; these figures and the distribution of SRFs were similar in the two groups. A significant increase in the risk of complications could be seen with an increase in SRFs (p=0.0267) and with disease stages 2 and 3 (p=0.016). Tumor reduction surgery was also associated with an increase in complications (p=0.086). CONCLUSIONS In summary, tumor surgery is associated with considerable risks in children. Therefore it is very important to look for new approaches that could potentially minimize these risks. As the causes of surgical complications are multifactorial, we are of the opinion that intensified surgical planning can contribute to reducing risks. Particularly neuroblastoma surgery could profit from an increased use of 3D visualization and improved preoperative planning.

Predicting Postoperative Complications After Pediatric Perforated Appendicitis

ABSTRACT Purpose: Assessment of risk factors for postoperative complications following surgical treatment of pediatric perforated appendicitis (PA) is necessary to identify those patients in need of closer monitoring. In this study, we have investigated the impact of different risk factors on the occurrence of complications after an appendectomy in children with PA. Material and Methods: The study was a retrospective, single-centre analysis of all pediatric PA conducted over a 10-year period. Preoperative clinical and laboratory results, intraoperative findings, and postoperative complications were analyzed. Risk factors were defined and a risk score was determined for postoperative complications and reinterventions. Results: Surgical treatment for appendicitis was performed in 840 pediatric patients during the observation period. 163 of the included patients were diagnosed with PA (mean age 8.9 ± 3.6 years). 19 (11.7%) patients developed postoperative complications, 17 (10.4%) of which required complication-related intervention. We identified five predictors of postoperative complications: the C-related protein value at admission, purulent peritonitis, open appendectomy (primary, secondary, or converted), placement of an abdominal drain, and administration of antibiotics not compliant to results from the subsequent antibiogram. The determined risk score was significantly higher in the complication group (p < .0001) and reintervention group (p < .001). Conclusions: Postoperative complications following pediatric PA can be predicted using specific preoperative, intraoperative, and postoperative risk factors. In the high-risk group, an active prevention, detection, and intervention of any occurring complication is necessary and we present a new specific pediatric risk score to define patients at risk for complications.

[Childhood kidney tumors -- the relevance of imaging].

Zusammenfassung6,2% der kindlichen Tumorerkrankungen betreffen die Nieren. Anamnese, Klinik und radiologischer Befund führen zur Differenzialdiagnose der verschiedenen Nierentumoren. Im Falle eines Nephroblastoms erfolgt die therapierelevante Diagnose allein radiologisch ohne histologische Sicherung. Im Rahmen der Therapieoptimierungsstudien der Gesellschaft für Pädiatrische Onkologie und Hämatologie wird eine präoperative Chemotherapie durchgeführt. Während und nach der präoperativen Chemotherapie erfolgt bildgebend ein Therapiemonitoring, um ein Ansprechen des Tumors auf die Therapie zu belegen. Das radiologische Staging hat große Bedeutung für die weitere Therapie und beeinflusst die Operationsplanung. Die präoperative Planung wird durch 3D-Visualisierung erleichtert. Die Relevanz der radiologischen Diagnostik von Nierentumoren im Kindesalter ergibt sich zusammenfassend aus Differenzialdiagnostik, Staging, Therapiemonitoring und Operationsplanung.AbstractKidney tumors represent 6.2% of malignant tumors in children. History, clinical course and radiological findings are necessary elements in the differential diagnosis of the different renal tumors. In the case of nephroblastoma, chemotherapy is based solely on the radiological diagnosis without prior histology. In therapy-optimizing studies of the Society of Pediatric Oncology and Hematology, preoperative chemotherapy is performed. Therapy monitoring is performed in the course of and after preoperative chemotherapy to verify tumor response. Radiological staging plays a significant role in deciding on further treatment and in operative planning. Three-dimensional visualization of the abdominal situs can assist preoperative planning. In summary, diagnostic imaging in renal tumors in children plays a role in differential diagnosis, staging, monitoring of therapy, and surgical planning.Kidney tumors represent 6.2% of malignant tumors in children. History, clinical course and radiological findings are necessary elements in the differential diagnosis of the different renal tumors. In the case of nephroblastoma, chemotherapy is based solely on the radiological diagnosis without prior histology. In therapy-optimizing studies of the Society of Pediatric Oncology and Hematology, preoperative chemotherapy is performed. Therapy monitoring is performed in the course of and after preoperative chemotherapy to verify tumor response. Radiological staging plays a significant role in deciding on further treatment and in operative planning. Three-dimensional visualization of the abdominal situs can assist preoperative planning. In summary, diagnostic imaging in renal tumors in children plays a role in differential diagnosis, staging, monitoring of therapy, and surgical planning.

Kindliche Nierentumoren — Relevanz der Bildgebung

Zusammenfassung6,2% der kindlichen Tumorerkrankungen betreffen die Nieren. Anamnese, Klinik und radiologischer Befund führen zur Differenzialdiagnose der verschiedenen Nierentumoren. Im Falle eines Nephroblastoms erfolgt die therapierelevante Diagnose allein radiologisch ohne histologische Sicherung. Im Rahmen der Therapieoptimierungsstudien der Gesellschaft für Pädiatrische Onkologie und Hämatologie wird eine präoperative Chemotherapie durchgeführt. Während und nach der präoperativen Chemotherapie erfolgt bildgebend ein Therapiemonitoring, um ein Ansprechen des Tumors auf die Therapie zu belegen. Das radiologische Staging hat große Bedeutung für die weitere Therapie und beeinflusst die Operationsplanung. Die präoperative Planung wird durch 3D-Visualisierung erleichtert. Die Relevanz der radiologischen Diagnostik von Nierentumoren im Kindesalter ergibt sich zusammenfassend aus Differenzialdiagnostik, Staging, Therapiemonitoring und Operationsplanung.AbstractKidney tumors represent 6.2% of malignant tumors in children. History, clinical course and radiological findings are necessary elements in the differential diagnosis of the different renal tumors. In the case of nephroblastoma, chemotherapy is based solely on the radiological diagnosis without prior histology. In therapy-optimizing studies of the Society of Pediatric Oncology and Hematology, preoperative chemotherapy is performed. Therapy monitoring is performed in the course of and after preoperative chemotherapy to verify tumor response. Radiological staging plays a significant role in deciding on further treatment and in operative planning. Three-dimensional visualization of the abdominal situs can assist preoperative planning. In summary, diagnostic imaging in renal tumors in children plays a role in differential diagnosis, staging, monitoring of therapy, and surgical planning.Kidney tumors represent 6.2% of malignant tumors in children. History, clinical course and radiological findings are necessary elements in the differential diagnosis of the different renal tumors. In the case of nephroblastoma, chemotherapy is based solely on the radiological diagnosis without prior histology. In therapy-optimizing studies of the Society of Pediatric Oncology and Hematology, preoperative chemotherapy is performed. Therapy monitoring is performed in the course of and after preoperative chemotherapy to verify tumor response. Radiological staging plays a significant role in deciding on further treatment and in operative planning. Three-dimensional visualization of the abdominal situs can assist preoperative planning. In summary, diagnostic imaging in renal tumors in children plays a role in differential diagnosis, staging, monitoring of therapy, and surgical planning.

YouTube as a Potential Training Resource for Laparoscopic Fundoplication

OBJECTIVE To analyze the surgical proficiency and educational quality of YouTube videos demonstrating laparoscopic fundoplication (LF). DESIGN In this cross-sectional study, a search was performed on YouTube for videos demonstrating the LF procedure. The surgical and educational proficiency was evaluated using the objective component rating scale, the educational quality rating score, and total video quality score. Statistical significance was determined by analysis of variance, receiver operating characteristic curve, and odds ratio analysis. RESULTS A total of 71 videos were included in the study; 28 (39.4%) videos were evaluated as good, 23 (32.4%) were moderate, and 20 (28.2%) were poor. Good-rated videos were significantly longer (good, 22.0 ± 5.2min; moderate, 7.8 ± 0.9min; poor, 8.5 ± 1.0min; p = 0.007) and video duration was predictive of good quality (AUC, 0.672 ± 0.067; 95% CI: 0.541-0.802; p = 0.015). For good quality, the cut-off video duration was 7:42 minute. This cut-off value had a sensitivity of 67.9%, a specificity of 60.5%, and an odds ratio of 3.23 (95% CI: 1.19-8.79; p = 0.022) in predicting good quality. Videos uploaded from industrial sources and with a higher views/days online ratio had a higher objective component rating scale and total video quality score. In contrast, the likes/dislikes ratio was not predictive of video quality. CONCLUSIONS Many videos showing the LF procedure have been uploaded to YouTube with varying degrees of quality. A process for filtering LF videos with high surgical and educational quality is feasible by evaluating the video duration, uploading source, and the views/days online ratio. However, alternative videos platforms aimed at professionals should also be considered for educational purposes.

Significance of the Extent of Intestinal Resection on the Outcome of a Short-bowel Syndrome in a Porcine Model.

ABSTRACT Aim of the study: Insufficient data are available to determine the most suitable extent of intestinal resection required to induce short-bowel syndrome (SBS) in pigs. This study aimed to compare the three main SBS-models published. Methods: A 75%, 90%, or 100% mid-intestinal resection was performed in groups of n = 5 pigs each. Clinical (body weight, stool consistency) and biochemical (serum eletrolytes, citrulline, albumin, prealbumin, and transferrin) parameters were determined daily, functional (D-xylose resorption) and histological (intestinal villus length) parameters were determined after 2 weeks. A t-test and ANOVA were used for statistical analysis. Results: Only in the 100% group, we observed a persistent weight loss (13.6 ± 3.8%) and diarrhea, as well as a decrease in prealbumin-levels (41%) and transferrin levels (33%). Serum electrolytes remained stable in all groups during the observation period. Citrulline stabilized at different levels (100% group 13.9 ± 1.0 μmol/L; 90% group 18.8 ± 1.0 μmol/L; 75% group 26.3 ± 1.4 μmol/L; all p < .05). D-xylose resorption was lowest in the 100%, followed by 90% and 75% group (100% group 32.8 ± 4.9 mg/L; 90% group 50.0 ± 19.6 mg/L; 75% group 57.8 ± 8.8 mg/L; p = .393). Intestinal villus length decreased in all groups (100% group 11.0%; 90% group 14.0%; 75% group 19.1%). Conclusions: 75% intestinal resection is less suitable as an SBS model, as animals tend to recover remarkably. The 90% model is suitable for longer-term studies, as animals might survive longer due to partial compensation. Due to severe nutritional, biochemical, and physiological derangements, the 100% model can only be used for acute experiments and those immediately followed by small bowel transplantation.