Frequency of ectopic and supernumerary intrathymic parathyroid glands in patients with renal hyperparathyroidism: analysis of 461 patients undergoing initial parathyroidectomy with bilateral cervical thymectomy.

BACKGROUND: The frequency of intrathymic parathyroid glands (IPGs) in patients undergoing parathyroidectomy for renal hyperparathyroidism (rHPT) varies considerably between 14.8% and 45.3%. Total parathyroidectomy with autotransplantation and subtotal parathyroidectomy are the most accepted surgical procedures to treat patients with rHPT. However, routine bilateral cervical thymectomy (BCT) is still discussed, although controversially. METHODS: From a prospective database of patients who underwent parathyroid surgery for rHPT between 1975 and 2009, patients with routine BCT at initial PTX were further analyzed regarding the frequency of ectopic and supernumerary IPGs. Duration of hemodialysis and stage of chronic kidney disease were correlated with the frequency of supernumerary IPGs to elucidate a potential role of long-standing proliferation stimuli to any surplus parathyroid tissue. RESULTS: Initial parathyroidectomy with BCT was performed in 461 patients. IPGs were resected in 205 of them (44.5%). They were ectopic in 181 (39.3%) and supernumerary in 30 patients (6.5%). The frequency of supernumerary IPGs in patients on permanent hemodialysis was 7.4% (29/392), 3.9% (1/26) in predialysis patients, and 0% (0/43) in patients after successful kidney transplantation. This differences reached no statistical significance. CONCLUSIONS: BCT is essential in patients with fewer than four parathyroid glands identified at typical positions. Because of the low frequency of supernumerary IPGs and a suspected low proliferation stimulus, the relevance of BCT after resection of four glands in predialysis patients and those after successful kidney transplantation must be questioned. Nevertheless, routine BCT seems to be acceptable and can be recommended in patients on permanent hemodialysis not awaiting kidney transplantation until proven otherwise by prospective trials.

[Simulation of laparoscopic surgery--four years' experience at the Department of Surgery of the University Hospital Marburg]. / Simulation endoskopischer Operationen - Vier Jahre Erfahrung an der Chirurgischen Universitätsklinik Marburg.

It is well known that learning curves are longer for laparoscopic surgery compared to open surgery. Recently, virtual reality (VR) simulation was developed as alternative to conventional training. Such a new training system makes it possible to offer a wide range of repeatable surgical situations, and thus, enable assessments based on direct observation of performance. During the last four years we did several studies using a VR simulator (LapSim). After a constructive validity study - discrimination between novices and experienced laparoscopic surgeons, we were able to show that advanced residents benefit most from a three-day practical course for laparoscopic surgery, while - in a further investigation - we found contrary to training at the Pelvitrainer that novices in laparoscopic surgery have the most benefit from VR training. Minimally invasive surgery is significantly more sophisticated for the surgeon than open surgery. While Research on laparoscopic surgery has focused primarily on the development and assessment of technical skills, non technical skills such as visual-spatial perception and stress coping has received much less attention. We showed that spatial perception as well as stress coping positively correlates with virtual laparoscopic skills. A high degree of spatial perception led to faster adaption to a non-stereo environment and correlated with high level of laparoscopic skills. Furthermore, Ineffective stress-coping strategies correlate with poor virtual laparoscopic performance. VR simulation seems to be a promising tool to improve laparoscopic skills in a modern apprenticeship model. According to patient safety, the development of this instrument for surgery should be advanced professionally just as a flight simulators in aviation.

An economic comparison of surgical and medical therapy in patients with secondary hyperparathyroidism--the German perspective.

BACKGROUND: Treatment options for secondary hyperparathyroidism were significantly amended with the introduction of cinacalcet and paricalcitol. Limitations of resources in public health systems demand detailed analyses of accruing costs. The aim of this study was to compare the costs of these new treatment modalities to surgery. METHODS: Patients who underwent initial parathyroidectomy (n = 91) and patients treated with cinacalcet or paricalcitol (n = 100) at an ambulatory dialysis center between 01/2003 and 12/2006 were analyzed. The revenues of both therapies for the funding agencies were calculated by a cost-cost analysis. The real arising costs of the supplier were analyzed and compared to the revenues. RESULTS: Treatment costs for cinacalcet (60 mg/day/year) were 5828.40€ and 4485.20€ for paricalcitol (15 µg/week/year). Revenues for inpatient surgical treatment according to the German DRG system were 3755.38€/case. Additionally, costs for postoperative ambulatory therapies were 545.05€ for the first year and 384.97€ for the following. CONCLUSION: Due to linearly increases, expenses of medical treatment with cinacalcet for more than 9 months or paricalcitol for more than 12 months exceeded the costs of surgical therapy. The indication of these new medical therapies should be restricted to patients as an interim solution ahead of surgery or in patients considered unfit for surgery.

Are diabetic patients at a greater risk to develop a vocal fold palsy during thyroid surgery than nondiabetic patients?

BACKGROUND: Diabetic neuropathy is reported to be an independent risk factor for the development of a vocal fold palsy (VFP), and nerves in diabetic patients are suspected to have an increased vulnerability to mechanical trauma. This retrospective study was performed to find out whether diabetic patients were at a greater risk to acquire VFP than were nondiabetic patients in a large cohort who underwent thyroid surgery. METHODS: Records of patients who underwent initial thyroid surgery at our institution between 1995 and 1999 were reevaluated. Results of preoperative and postoperative laryngoscopy, repeated laryngoscopy 6 months after operation, and concomitance of diabetes were registered. RESULTS: Six hundred thirty patients were retrospectively analyzed. Preoperative laryngoscopy revealed a unilateral VFP in 3 of 44 diabetic patients (6.8%) and in 4 of 586 (0.7%) nondiabetic patients. Five of 44 diabetic patients (11.4%) and 49 of 586 nondiabetic patients (8.4%) acquired VFP perioperatively, which was permanent in 2 diabetic patients (4.5%) and 8 nondiabetic patients (1.4%). The incidence of preoperative VFP in the diabetic patients was significantly greater than in nondiabetic patients (P = .0091). The incidence of postoperative and permanent VFP did not differ significantly. CONCLUSION: Thyroid surgery can be performed safely in diabetic patients, as they are not at a greater risk to acquire VFP than nondiabetic patients.

Comparison of total parathyroidectomy without autotransplantation and without thymectomy versus total parathyroidectomy with autotransplantation and with thymectomy for secondary hyperparathyroidism: TOPAR PILOT-Trial.

BACKGROUND: Secondary hyperparathyroidism (sHPT) is common in patients with chronic renal failure. Despite the initiation of new therapeutic agents, several patients will require parathyroidectomy (PTX). Total PTX with autotransplantation of parathyroid tissue (TPTX+AT) and subtotal parathyroidectomy (SPTX) are currently considered as standard surgical procedures in the treatment of sHPT. Recurrencerates after TPTX+AT or SPTX are between 10% and 12% (median follow up: 36 months). Recent retrospective studies demonstrated a lower rate of recurrent sHPT of 0-4% after PTX without autotransplantation and thymectomy (TPTX) with no higher morbidity when compared to the standard procedures. The observed superiority of TPTX is flawed due to different definitions of outcomes, varying follow up periods and different surgical treatment strategies (with and without thymectomy). METHODS/DESIGN: Patients with sHPT (intact parathyroid hormone > 10 times above the upper limit of normal) on long term dialysis (>12 months) will be randomized either to TPTX or TPTX+AT and followed for 36 months. Outcome parameters are recurrence rates of sHPT, frequencies of reoperations due to refractory hypoparathyroidism or recurrent/persistent hyperparathyroidism, postoperative morbidity and mortality and quality of life. 50 patients per group will be randomized in order to obtain relevant frequencies of outcome parameters that will form the basis for a large scale confirmatory multicentred randomized controlled trial. DISCUSSION: sHPT is a disease with a high incidence in patients with chronic renal failure. Even a small difference in outcomes will be of clinical relevance. To assess sufficient data about the rate of recurrent sHPT after both methods, a multicentred, randomized controlled trial (MRCT) under standardized conditions is mandatory. Due to the existing uncertainties the calculated number of patients necessary in each treatment arm (n > 4000) makes it impossible to perform this study as a confirmatory trial. Therefore estimates of different outcomes are performed using a pilot MRCT comparing 50 versus 50 randomized patients in order to establish a hypothesis that can be tested thereafter. If TPTX proves to have a lower rate of recurrent sHPT, no relevant disadvantages and no higher morbidity than TPTX+AT, current surgical practice may be changed. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number Registration (ISRCTN86202793).

Evaluation of MR-angiography for pre-operative assessment of living kidney donors.

INTRODUCTION: Pre-operative magnetic resonance tomography (MR) and MR-angiography (MRA) have rendered favorable results for the assessment of renal anatomy preceding living-related kidney transplantation. However, limited value of MRA in the detection of accessory renal vasculature is reported. METHODS: We compared the results of pre-operative contrast-medium-enhanced MRA of the last 30 consecutively performed nephrectomies in living kidney donors with the intraoperative findings of vascular, parenchymal, and ureteral anatomy. RESULTS: Pre-operative MRA diagnosed a solitary renal artery in 24 cases (80%) and a normal venous, ureteral and parenchymal anatomy in all cases. Intraoperatively, the surgeon confirmed the normal pre-operative MRA findings of ureter and parenchyma. Yet, in 6 out of 30 patients (20%) vascular architecture differed from the pre-operative imaging: four of them, who had a radiologically regular anatomy, were found to have accessory vessels upon surgical preparation. In the fifth patient, MRA revealed an accessory lower polar artery, which was confirmed during surgery. An undiagnosed third arterial vessel, located behind the renal vein, led to an aortic bleeding. In the sixth case, the adrenal gland artery was misinterpreted as an accessory superior polar artery of the kidney in MRA. Additionally, a radiologically undetected inferior polar artery was dissected during nephrectomy and led to partial hypoperfusion of the graft. Subsequent retrospective reevaluation of the MRA by experienced radiologists was unable to identify the intraoperative anatomical discrepancies. Hence, sensitivity of MRA was 60% (6 out of 10 cases) for accessory renal vessel detection and 80% (24 out of 30 cases) for overall sensitivity in determining renal vessel number. DISCUSSION: MRA is a reliable method for the non-invasive investigation of living kidney donors and provides valuable information required by the surgeon. But, as the technique misses small diameter vessels, it cannot be recommended as sole diagnostic tool in unclear cases.