Finite-element-modeling of egg white as a substitute for tissue coagulation during bipolar radiofrequency-induced thermofusion.

Radiofrequency-induced thermofusion is a frequently used electrosurgical procedure for the sealing of blood vessels. A disadvantage of vessel sealing instruments is that the generated thermal energy spreads to the surrounding tissue and may irreversibly damage it. This is particularly problematic when operating close to sensitive structures such as nerves. Given their advantages, there is nonetheless a lot of interest in using bipolar vessel sealing for surgical procedures. To select instruments that may be safely used in such cases, it is important to reliably quantify the thermal spread to the surrounding tissue. Mathematical models can help to evaluate the transient behavior, that is the evolution of the thermal spread over time, more precisely. A finite element model allows for a detailed analysis of inhomogeneities in the spatial temperature distribution. As a first step towards a finite model of the bipolar vessel sealing process, a model of the coagulation of chicken egg white is presented here. Egg white has thermal and electrical properties that are very similar to tissue, making it suitable as a substitute for the analysis of the coagulation process. It has the additional advantage, that the spatial and temporal evolution of the thermal spread can be visually gauged. The presented model describes the experimentally observed spatial temperature distribution, the shape of the coagulated egg white, and the formation of hotspots. Furthermore, it is shown that the model can correctly predict the shape of the coagulated egg white in further experiments.

Clinical characteristics, pathological reevaluation, surgical management and adjuvant therapy of patients with endometrial stromal tumors.

PURPOSE: To review a single-center experience over a 27-year period in the management of endometrial stromal sarcoma (ESS) and undifferentiated endometrial sarcoma (UES) for insight into clinical characteristics, pathological diagnosis, surgical practice, adjuvant therapy and clinical outcome. MATERIALS AND METHODS: This was a retrospective study of women with histologically proven ESS and UES who were treated at the Department of Obstetrics and Gynecology, University of Tuebingen, Germany, between 1983 and 2010. Available tumor tissue, as well as inpatient and ambulatory records were reviewed; follow-up and survival data were ascertained. RESULTS: The study sample comprised ten patients with ESS and seven patients with UES. Primary surgical treatment consisted of total hysterectomy in nine patients (90.0 %) with ESS and six patients (85.7 %) with UES; one patient (10.0 %) with ESS and one patient (14.3 %) with UES underwent debulking surgery. All patients (100 %) from the ESS group and six patients (85.7 %) from the UES group underwent bilateral salpingo-oophorectomy. Seven women (70.0 %) with ESS and six women (85.7 %) with UES underwent lymphadenectomy. Median DFS was 83.8 months (95 % CI 80.6-87.0) and median OS was 232.6 (95 % CI 49.3-415.9) for patients with ESS; median DFS was 12.9 months (95 % CI 0-284.1) and median OS was 17.6 (95 % CI 0-37.0) for patients with UES. There was no significant difference in DFS between patients with ESS as compared with patients with UES. However, patients with ESS had a significantly better OS when compared to patients with UES (p = 0.011). CONCLUSION: ESS and UES are very rare uterine neoplasms. Surgery consisting of total hysterectomy with or without bilateral salpingo-oophorectomy is the most important treatment-element in patients with ESS or UES.

A mathematical model of bipolar radiofrequency-induced thermofusion.

Bipolar radiofrequency-induced thermofusion has become a widely accepted method successfully used in open and particularly in minimally-invasive surgery for the sealing of blood vessels and tissue of up to several millimeters diameter. Despite its wide-spread application, the thermofusion process itself is not well understood on a quantitative and dynamic level, and manufacturers largely rely on trial-and-error methods to improve existing instruments. To predict the effect of alternative generator control strategies and to allow for a more systematic approach to improve thermofusion instruments, a mathematical model of the thermofusion process is developed. The system equations describe the spatial and temporal evolution of the tissue temperature due to Joule heating and heat transfer, and the loss of tissue water due to vaporization. The resulting effects on the tissue properties, most importantly the electrical resistivity, heat capacity and thermal conductivity, are considered as well. Experimental results indicate that the extent of the lateral thermal damage is directly affected by Joule heating of the lateral tissue. The experimental findings are supported by simulation results using the proposed mathematical model of thermofusion.

Cervical Detachment Using Monopolar SupraLoop™ Electrode versus Monopolar Needle in Laparoscopic Supracervical Hysterectomy (LSH): An Interventional, Comparative Cohort Study.

Objective: Currently available monopolar loop electrodes are difficult to handle in laparoscopic supracervical hysterectomy (LSH) and are entirely disposable devices, generating additional operating costs. The aim of this interventional study was the comparison of the efficiency and safety of cervical detachment with a newly developed monopolar loop electrode (SupraLoop™) with a conventional method of cervical detachment in LSH. Material and Methods: Our study sample included 1598 patients; 1070 patients that underwent LSH with cervical detachment using the monopolar SupraLoop™ (study group) and 528 patients that underwent LSH with cervical detachment using the monopolar needle (control group). We also assessed cervical detachment time and total device application and cutting time in a subgroup of 49 patients (23 patients from the study group and 26 patients from the control group). Results: Total operation time for LSH was significantly shorter among SupraLoop™ patients (93 ± 41 minutes) when compared to patients in whom cervical detachment was performed with the needle (105 ± 44 minutes) (p < 0.001). Cervical detachment time and total device application including cutting time was significantly shorter for the SupraLoop™ group (SupraLoop vs. needle; 0.12 ± 0.21 min vs. 5.1 ± 4.4 min [p < 0.001]; 2.3 ± 1.8 min vs. 5.4 ± 2.4 min [p < 0.001]). There were no major or minor complications directly related to the use of the SupraLoop™ device, whereas two intraoperative complications were directly related to the application of the monopolar needle. Conclusion: The newly developed monopolar loop electrode (SupraLoop™) is both an effective and safe instrument for cervical detachment in laparoscopic supracervical hysterectomy, and performed better than the needle, offering a significantly shorter operating time and less complications for the hysterectomy compared to the conventional method.

Surgical and Conservative Management of Symptomatic Leiomyomas during Pregnancy: a Retrospective Pilot Study.

Purpose: Evidence regarding distinguishing characteristics of women with symptomatic leiomyomas during pregnancy who undergo myomectomy during pregnancy and those who respond to conservative treatment is sparse because it mostly derives from case reports and small patient series. As the first of its type, the present study analyzed the characteristics of women with symptomatic leiomyomas treated with myomectomy during pregnancy and those treated conservatively. Methods: We performed a computer search of medical records from 1 January 2001 to 31 March 2011 using the International Classification of Diseases Codes for pregnancy, myomectomy and leiomyomas during pregnancy. Results: 27 patients were admitted during pregnancy directly related to leiomyomas; 17 of the 27 patients received conservative treatment for symptomatic leiomyomas, and 10 patients had surgery during pregnancy: 3 had undergone diagnostic surgical procedures and 7 myomectomy. Perioperative and postoperative morbidity was low in all women in our sample. Conclusion: In our pilot study, myomectomy during pregnancy was safely performed in carefully selected patients, with subserosal or pedunculated leiomyomas that failed to respond to conservative treatment, with low perioperative and postoperative morbidity.

Nodal status--its impact on prognosis in advanced ovarian cancer.

PURPOSE: Prognostic impact of nodal status or lymphadenectomy in advanced ovarian cancer is still unclear. Known best prognostic impact in advanced ovarian cancer has the residual tumor mass. The aim of this retrospective study is to examine the importance of nodal status in correlation with residual tumor mass. METHODS: One hundred and fifty-seven consecutive patients with primary stage III ovarian cancer underwent surgery between 01/2000 and 06/2007 at the Department of gynecology and obstetrics, University Hospital, Tübingen, Germany. All patients got stage-related surgery and platin-based chemotherapy. Median follow-up time was 53.5 months, and all patients were included in the study. RESULTS: Resection status and nodal status are significant prognostic factors in our study (P < 0.001). In FIGO III, patients without residual tumor (R0) had significant best OS and PFS independent to node status (N0/N+; P = 0.002) compared to patients with residual tumor. In contrast, node status had significant positive impact on PFS in patients without residual tumor and node negativity. With the increase in residual tumor, the influence of lymphnode metastases on prognosis is decreasing. CONCLUSION: Main intention of primary surgery is R0 resection with best prognosis in advanced stages. A systematic lymphadenectomy in cases with R0 resection or residual tumor <1 cm seems to be reasonable with positive impact on prognosis. Node status has impact on prognosis in patients with negative node after R0 resection with best PFS in FIGO III. Further prospective studies had to show whether systematic lymphadenectomy in suboptimally tumor-reduced patients can improve prognosis.

Fertility preservation in prepubertal girls prior to chemotherapy and radiotherapy--review of the literature.

Significant improvement in the survival rates of children with pediatric cancers has been achieved over the last 25 years, so the number of long-term survivors is increasing and their subsequent quality of life is of increasing importance. One of the most serious side effects of chemotherapy or radiotherapy is damage to the ovarian function, which can lead to loss of fertility. The degree of this damage depends on the substances used, the dose of radiotherapy reaching the ovaries, and the age of the girl at the time of treatment. Up to now, the only established method of fertility preservation has been cryoconservation of fertilized egg cells or embryos, but this is not possible in prepubertal girls because of their sexual immaturity. Removal of ovarian tissue and subsequent cryoconservation with the option of later orthotopic retransplantation is therefore an option to these girls. This method can lead to pregnancy and birth in adult women. Up to now there are no studies about the retransplantation of ovarian tissue which was removed before puberty. Displacement of the ovaries away from the radiation field before radiation to the pelvic area can be considered; however, the data is controversial. One problem in the use of fertility preservation methods in these very young patients is that they undergo procedures which, because of their age, they mostly do not understand and the parents must make a decision based on the assumed later wishes of their daughter.

Endometrial Cancer: Comparison of Patients with Synchronous Primary Carcinoma of the Endometrium and Ovary vs. Endometrial Carcinoma with Ovarian Metastases.

Purpose: The aim of our study was to investigate the rate of secondary carcinomas in patients with endometrial carcinoma (EC). In particular, we wanted to describe the subset of patients with endometrial and simultaneous ovarian carcinoma (OC), including outcomes. The study also compared patients with EC and ovarian metastasis with patients with EC and simultaneous OC. Patients and Methods: Data from 251 patients with primary endometrial carcinoma who underwent surgery in the years 2005-2009 at the Department of Obstetrics and Gynaecology, University of Tübingen, were analysed retrospectively. Results: A total of 28 patients (11.1 %) had a secondary carcinoma: 18 patients (7.1 %) had OC; 9 (3.5 %) patients had a history of breast cancer, and one patient (0.4 %) respectively had simultaneous carcinoma of the vulva or bladder. 14 patients (5.5 %) had advanced stage EC with ovarian metastasis or, in one case, metastasis to the ovarian tube. Patients with ovarian metastasis had a mean age of 71.2 ± 9.2 years at primary diagnosis, making them significantly older compared to patients with EC and simultaneous OC (55.3 ± 11.8 years, p < 0.001). Moreover, patients with ovarian metastasis significantly more often had EC with a higher tumour grade (grade 1: 0, grade 2: 21.4 %, grade 3: 78.6 %) compared to patients with simultaneous EC and OC (grade 1: 11.1 %, grade 2: 77.8 %, grade 3: 11.1 %; p < 0.001). Conclusion: Almost one in 10 patients with EC had a secondary carcinoma. The most common secondary carcinoma was OC followed by breast cancer. This should be taken into account in the diagnosis and therapy of patients with EC. Patients with simultaneous EC and OC were significantly younger than patients with EC and ovarian metastasis. In addition, their tumour had better prognostic features: thus, the tumour grade of the EC was significantly lower. Overall, the prognosis for patients with synchronous EC and OC is better than that for patients with EC and ovarian metastasis.

Abdominal Access for Shoulder Dystocia as a Last Resort - a Case Report.

Shoulder dystocia is the term used to describe failure to progress in labour after the head has been delivered due to insufficient rotation of the shoulders. It is unpredictable and cannot be prevented by the midwife or the obstetrician. We report here on a severe case of shoulder dystocia, where delivery of the shoulder was finally achieved through direct pressure on the anterior shoulder after laparotomy and uterotomy with concurrent vaginal Woods screw manoeuvre and was followed by vaginal delivery. The patient presented risk factors like maternal obesity and administration of labour-inducing drugs. After different manoeuvres like McRoberts manoeuvre and several manoeuvres for internal rotation were carried out unsuccessfully, an emergency laparotomy was performed. The newborn was in need for reanimation and artifical ventilation postpartum but recovered fast during the following days. An Erb's palsy of the posterior arm improved during the hospital stay. The German Guideline of the DGGG 8 recommends a risk management plan and regular training to all birth attendants for obstetric clinics. Beside the vaginal manoeuvres one should have at least theoretical expertise in operative manoeuvres to be able to perform them in emergency cases.

Impaired bone microenvironment: correlation between bone density and presence of disseminated tumor cells.

BACKGROUND: Disseminated tumor cells (DTCs) in bone marrow (BM) occur in 30-40% of primary breast cancer patients. An impaired bone microenvironment may lead to reduced bone density and osteoporosis affecting the BM as a homing site for DTCs. The bone mineral density (BMD) and its correlation to DTC in BM was evaluated. MATERIALS AND METHODS: One hundred and eighty-one women (70 premenopausal, 111 postmenopausal) underwent quantitative ultrasonometry before adjuvant chemotherapy. BM aspirates were analyzed by immunocytochemistry using the ACIS system (Chromavision) based on immunostaining. RESULTS: DTCs were detected in 39% of the patients. Positive BM status correlated significantly with the nodal status. BMD was significantly reduced in the postmenopausal patients (p=0.003). Smaller tumors and higher BMD correlated significantly (p<0.014). Fifty percent of the patients with preclinical osteoporosis were BM positive, whereas 37% with normal or osteopenic BMD had DTCs. CONCLUSION: An impaired bone micro-environment as found in preclinical osteoporosis might be a homing site for DTCs.

[Fertility preservation for young patients with autoimmune diseases and the need for cytotoxic treatment. Clinical experiences from interdisciplinary consultation]. / Fertilitätserhaltende Maßnahmen bei jungen Frauen mit Autoimmunerkrankung vor zytotoxischer Therapie : Erfahrungen aus einer interdisziplinären Sprechstunde.

In cases of severe exacerbation of autoimmune diseases (AID) cytotoxic therapy, in particular with cyclophosphamide (CYC) is needed. As the peak occurrence of such AIDs occurs in young women during the childbearing years, preservation of fertility and the hormonal function of the ovaries are an interdisciplinary challenge.For ovarian protection several options exist. Gonadotropin-releasing hormone analogues in parallel with CYC treatment seem to reduce the cytotoxic effect on the ovaries. Fertilized and unfertilized oocytes can be conserved by cryoconservation after ovarian stimulation. A relatively new strategy uses cryopreservation and autotransplantation of human ovarian tissue prior to cytotoxic therapy. As all these methods are accompanied with side-effects and possible delays in the necessary CYC treatment, a close collaboration of gynecologists and internists is needed. The decision for the optimal preservation therapy should always be based on the individual patient.

[Are breast biopsies adequately funded? A process cost & revenue analysis]. / Ist die Mammabiopsie ausreichend finanziert? Eine Prozesskosten & Erlösbetrachtung.

PURPOSE: The objective of the study was to determine whether the various breast biopsy procedures specified in the S 3 guidelines are sensibly represented within the current German health system as considered from a cost evaluation perspective. MATERIALS AND METHODS: This prospectively designed multicenter study analyzed 221 breast biopsies at 7 institutions from 04/2006 to 01/2007. Core needle biopsies, vacuum-assisted biopsies and surgical open biopsies under sonographic or mammographic guidance were evaluated. During an analysis of process costs, the individual process steps were recorded in diagrammatic form and assigned to the true consumption of resources. The actual resource consumption costs were entered. A process-related breakeven analysis was conducted to check whether the reimbursement of individual biopsy types covers the costs. RESULTS: Only sonographically guided core needle biopsy and surgical open biopsy are adequately reimbursed in the current German health system. All other breast biopsies indicate a negative profit margin. The principal reasons for under-funding are found in the area of reimbursement of investment and non-personnel costs. CONCLUSION: The reimbursement of breast biopsies must be improved in order to guarantee nationwide care of the population using the breast biopsy methods recommended in the S 3 guidelines and to avoid disincentives with respect to breast biopsy indications.

Clinical Characteristics, Surgical Management and Adjuvant Therapy of Patients with Uterine Leiomyosarcoma: 27 Years of Experience.

Purpose: To review a single-center experience over a 27-year period in the management of uterine leiomyosarcoma (LMS) for insight into surgical practice, adjuvant therapy and clinical outcome. Material and Methods: This was a retrospective study of women with histologically proven uterine LMS who were treated at the Department of Obstetrics and Gynecology, University of Tuebingen, Germany, between 1983 and 2010. Inpatient and ambulatory records were reviewed; follow-up and survival data were ascertained. Results: The study sample comprised 32 patients with uterine LMS. Primary surgical treatment consisted of total abdominal hysterectomy in 28 patients (88 %) and laparoscopic total hysterectomy in 4 patients (12 %). Lymph nodes were dissected and evaluated in 17 women (53 %); positive lymph nodes were present in 1 patient (6 %). A total of 17 patients (53 %) received adjuvant therapy. Median follow-up for disease-free survival (DFS) was 35.6 months and median DFS was 27.0 months for all patients. The median follow-up for overall survival (OS) was 51.3 months and the median OS was 28.0 months for our study group. The 5-year survival rate was 30 %. There was no significant difference in DFS (p = 0.76) and OS (p = 0.51) between patients who received adjuvant therapy and those who did not. Conclusion: Uterine LMS are rare and aggressive uterine neoplasms with high recurrence rates and metastatic potential. Surgery consisting of total hysterectomy with or without bilateral salpingo-oophorectomy is the most important treatment-element in patients with uterine LMS. Lymphadenectomy should be reserved for patients with clinically suspicious nodes.