Simulating Surgical Skills in Animals: Systematic Review, Costs & Acceptance Analyses.

Background: Modern surgery demands high-quality and reproducibility. Due to new working directives, resident duty hours have been restricted and evidence exists that pure on-the-job training provides insufficient exposure. We hypothesize that supplemental simulations in animal models provide a realistic training to augment clinical experiences. This study reviews surgical training models, their costs and survey results illustrating academic acceptance. Methods: Animal models were identified by literature research. Costs were analyzed from multiple German and Austrian training programs. A survey on their acceptance was conducted among faculty and medical students. Results: 915 articles were analyzed, thereof 91 studies described in-vivo animal training models, predominantly for laparoscopy (30%) and microsurgery (24%). Cost-analysis revealed single-training costs between 307€ and 5,861€ depending on model and discipline. Survey results illustrated that 69% of the participants had no experience, but 66% would attend training under experienced supervision. Perceived public acceptance was rated intermediate by medical staff and students (4.26; 1-low, 10 high). Conclusion: Training in animals is well-established and was rated worth attending in a majority of a representative cohort to acquire key surgical skills, in light of reduced clinical exposure. Animal models may therefore supplement the training of tomorrow's surgeons to overcome limited hands-on experience until virtual simulations can provide such educational tools.

Peripheral nerve transfers change target muscle structure and function.

Selective nerve transfers surgically rewire motor neurons and are used in extremity reconstruction to restore muscle function or to facilitate intuitive prosthetic control. We investigated the neurophysiological effects of rewiring motor axons originating from spinal motor neuron pools into target muscles with lower innervation ratio in a rat model. Following reinnervation, the target muscle's force regenerated almost completely, with the motor unit population increasing to 116% in functional and 172% in histological assessments with subsequently smaller muscle units. Muscle fiber type populations transformed into the donor nerve's original muscles. We thus demonstrate that axons of alternative spinal origin can hyper-reinnervate target muscles without loss of muscle force regeneration, but with a donor-specific shift in muscle fiber type. These results explain the excellent clinical outcomes following nerve transfers in neuromuscular reconstruction. They indicate that reinnervated muscles can provide an accurate bioscreen to display neural information of lost body parts for high-fidelity prosthetic control.

Broadband Prosthetic Interfaces: Combining Nerve Transfers and Implantable Multichannel EMG Technology to Decode Spinal Motor Neuron Activity.

Modern robotic hands/upper limbs may replace multiple degrees of freedom of extremity function. However, their intuitive use requires a high number of control signals, which current man-machine interfaces do not provide. Here, we discuss a broadband control interface that combines targeted muscle reinnervation, implantable multichannel electromyographic sensors, and advanced decoding to address the increasing capabilities of modern robotic limbs. With targeted muscle reinnervation, nerves that have lost their targets due to an amputation are surgically transferred to residual stump muscles to increase the number of intuitive prosthetic control signals. This surgery re-establishes a nerve-muscle connection that is used for sensing nerve activity with myoelectric interfaces. Moreover, the nerve transfer determines neurophysiological effects, such as muscular hyper-reinnervation and cortical reafferentation that can be exploited by the myoelectric interface. Modern implantable multichannel EMG sensors provide signals from which it is possible to disentangle the behavior of single motor neurons. Recent studies have shown that the neural drive to muscles can be decoded from these signals and thereby the user's intention can be reliably estimated. By combining these concepts in chronic implants and embedded electronics, we believe that it is in principle possible to establish a broadband man-machine interface, with specific applications in prosthesis control. This perspective illustrates this concept, based on combining advanced surgical techniques with recording hardware and processing algorithms. Here we describe the scientific evidence for this concept, current state of investigations, challenges, and alternative approaches to improve current prosthetic interfaces.

Multiuse of Disposable Microsurgical Instruments as a Cost-Efficient Alternative for Training and Research.

Microsurgery demands significant preclinical training, often hampered by the high costs of the required microsurgery instruments. We hypothesized that recently available disposable microsurgery instruments provide sufficient quality and significantly reduced costs. In a comparative analysis with standard reusable instruments, participants performed equally with both instrument sets and recommended the disposable instruments for microsurgery training and research applications.

Power assisted liposuction to obtain adipose-derived stem cells: impact on viability and differentiation to adipocytes in comparison to manual aspiration.

BACKGROUND: Adipose-derived stem cells (ASCs) play a key role in tissue engineering approaches and are probably of major importance in the context of autologous fat transfer. A number of different tools for harvesting ASCs-containing fat tissue have been established. Such devices should be easy to handle, time saving, low priced, safe and provide a high amount of viable ASCs in the aspirate. Power-assisted liposuction (PAL) has not yet been described in the literature as a tool for fat harvesting for lipotransfer. Aim of this study was to investigate ASCs' viability in fat tissue harvested using PAL versus manual aspiration (MA). METHODS: Fat tissue was obtained from 9 donors undergoing abdominoplasty. Samples were divided into two sections. Out of each section fat was harvested using either PAL or MA. Number of isolated ASCs was defined, proliferation rate was determined and cell viability was assessed by flow cytometry. The ability of isolated ASCs to differentiate into mature adipocytes was analyzed by gene marker expression. RESULTS: The number of viable ASCs and the proliferation rates did not significantly differ between PAL and MA but cells harvested using PAL showed significantly higher expression levels of differentiation markers adiponectin, GLUT4 and PPARg. CONCLUSION: Our results show that PAL is a feasible method for harvesting fat tissue containing viable ASCs. Quantity and quality of PAL-harvested ASC is similar or even better, respectively, compared to ASCs harvested by MA.

Gastro-oesophageal reflux disease in type 2 diabetics: symptom load and pathophysiologic aspects - a retro-pro study.

BACKGROUND: Information about gastro-oesophageal reflux disease (GERD) in patients with Diabetes mellitus type 2 (T2D) is scarce, although the incidence of both disorders is increasing. METHODS: This "retro-pro" study compared 65 T2D patients to a control group of 130 age- and sex-matched non-diabetics. GERD was confirmed by gastroscopy, manometry, pH-metry and barium swallow. RESULTS: In patients with T2D compared to controls, dysphagia (32.3% vs. 13.1%; p = 0.001) and globus sensation (27.7% vs. 13.8%; p = 0.021) were found more frequently, whereas heartburn (76.9% vs. 88.5%; p = 0.046) and regurgitation (47.7% vs. 72.3%; p= 0.001) were predominant in non-diabetics. Despite higher body mass indices (31.1 ± 5.2 vs. 27.7 ± 3.7 kg/m²; p < 0.001), hiatal hernia was less frequent in T2D patients compared to controls (60.0% vs. 90.8%, p < 0.001). Lower oesophageal sphincter (LES) pressure was higher in patients with T2D (median 10.0 vs. 7.2 mmHg, p = 0.016). DeMeester scores did not differ between the groups. Helicobacter pylori infections were more common in T2D patients (26.2% vs. 7.7%, p = 0.001). Barrett metaplasia (21.5% vs. 17.7%), as well as low- (10.8% vs. 3.8%) and high-grade dysplasia (1.5% vs. 0%) were predominant in T2D patients. CONCLUSIONS: T2D patients exhibit different GERD symptoms, higher LES pressures and a decreased prevalence of hiatal hernia than non-diabetics, which may be related to worse oesophageal motility and, thus, a more functional rather than anatomical cause of GERD. Low-grade dysplasia was more than twice as high in T2D than in non-diabetics patients. TRIAL REGISTRATION: Ethics committee of the Medical University of Vienna, IRB number 720/2011.

Anatomy of the sural nerve: cadaver study and literature review.

BACKGROUND: The sural nerve is commonly used as donor for nerve grafting. Contrary to its constant retromalleolar position, formation and course of the proximal sural nerve show great variability. The coexistence of different and deceptive terminologies contributes to the complexity, and reviewing the international literature is confusing. Because detailed anatomical knowledge is essential for efficient and safe sural nerve harvesting, this study aims to bring clarity. METHODS: Previous sural nerve reports listed in the PubMed database and established anatomical textbooks were reviewed. Different terminologies were compared and adjusted. Anatomical details and variations were noted. Subtle prospective anatomical dissections and comparison with actual data followed. RESULTS: Two hundred twenty-one relevant reports were identified and worked up going back to the nineteenth century. Fourteen established German and English language anatomical textbooks were reviewed. Thirty lower limbs were dissected. In total, this study pools the information of more than 2500 sural nerves. CONCLUSIONS: This study covers all information about the sural nerve anatomy published internationally. The coexistence of different and confusing terminologies is pinpointed and adjusted to allow comparison of previous reports and to gain a coordinated data pool of more than 2500 investigated sural nerves. Detailed features are clearly described and summarized, findings from the authors' own prospective dissections complete these data, and the prior existing anatomical confusion is resolved. Finally, clinical implications are described.

Neoadjuvant chemotherapy increases the rate of breast conservation in lobular-type breast cancer patients.

INTRODUCTION: Our study aims to determine whether patients with lobular-type breast cancer have significantly improved rates of breast conservation (BCT) after neoadjuvant chemotherapy (nCT). METHODS: Patients who received nCT and surgery within three prospective trials between 1995 and 2007 at the Medical University of Vienna were retrospectively analyzed. RESULTS: 325 patients had median follow-up of 53 months; 21% had lobular cancer, and 70% of these women were initially scheduled for mastectomy (MX). Twenty-one finally received BCT, yielding a MX-BCT turnover rate of 45%. Of patients primarily scheduled for BCT, 20% had to finally undergo MX in lobular cancer. The 256 patients with ductal-type breast cancer finally had a MX-BCT turnover rate of 52% (p = 0.561 versus lobular) and a BCT-MX turnover rate of 15% (p = 0.933 versus lobular). Secondary MX after initial BCT was necessary in 2% (ductal) and 10% (lobular, p = 0.110). There was no difference in local recurrence in lobular- as compared with ductal-type breast cancer patients after BCT (2.7% versus 10%, p = 0.135), nor was a difference seen in lobular breast cancer patients when comparing BCT with MX (2.7% versus 3.4%, p = 0.795). Tumor type was not an independent predictor for either BCT or local recurrence. CONCLUSION: We do not suggest excluding patients with lobular-type breast cancer who are primarily scheduled for MX from nCT, since BCT rates may still increase by 45% without influencing the oncologic outcome.

Preoperative lower esophageal sphincter manometry data neither impact manifestations of GERD nor outcome after laparoscopic Nissen fundoplication.

BACKGROUND: Experience with laparoscopic antireflux surgery (LARS) in patients with gastroesophageal reflux disease (GERD) and manometrically intact lower esophageal sphincter (LES) is limited. The disease pattern may be different and LARS may fail to control reflux or result in higher rates of dysphagia. This is the first study investigating the impact of preoperative LES manometry data not only on manifestations of GERD and subjective outcome alone but also on objective outcomes 1 year after LARS. METHODS: Three hundred fifty-one GERD patients underwent LARS and had subjective symptom and quality of life assessment, upper gastrointestinal endoscopy, barium swallow esophagogram, 24-h esophageal pH monitoring, and manometry pre- and 1 year postoperatively. Patients were divided into those with a preoperatively intact versus defective LES based on intraabdominal length and resting pressure. Baseline and 1-year postoperative follow-up data were compared. RESULTS: Preoperative manifestations of GERD were similar in each group. Postoperatively, all symptoms except flatulence, quality of life scores, and objective manifestations improved significantly in each group. CONCLUSIONS: The preoperative manometric character of the LES neither impacts the manifestations of GERD nor subjective and objective outcomes after LARS. Patients with GERD and manometrically intact LES have no higher risk for postoperative dysphagia.

The use of medication after laparoscopic antireflux surgery.

BACKGROUND: Laparoscopic antireflux surgery (LARS) significantly improves symptoms of gastro-esophageal reflux disease (GERD) and quality of life. Nevertheless, 14-62% of patients report using antisecretory medication after surgery, although only a tiny percentage has proven recurrence of GERD. We sought to determine symptoms of GERD, quality of life, and use of medication before and after LARS, and to compare our findings with those from previous studies. METHODS: Five hundred fifty-three patients with GERD who underwent LARS were evaluated before and at 1 year after surgery. After surgery, multidisciplinary follow-up care was provided for all patients by surgeons, psychologists, dieticians, and speech therapists. RESULTS: Symptoms of GERD and quality of life improved significantly and only 4.2% of patients still required medication after surgery [proton pump inhibitors (PPI) (98.4 vs. 2.2%; p < 0.01), prokinetics (9.6 vs. 1.1%; p < 0.01), and psychiatric medication (8 vs. 1.6%; p < 0.01)]. CONCLUSION: LARS significantly reduced medication use at 1-year follow-up. However, these effects might be attributed, in part, to the multidisciplinary follow-up care. Further studies are therefore required to investigate which patients may benefit from multidisciplinary follow-up care and whether its selective application may reduce the need for medication after LARS.

Is Endocrine Therapy Really Pleasant? Considerations about the Long-Term Use of Antihormonal Therapy and Its Benefit/Side Effect Ratio.

Endocrine therapy has become a key part in the adjuvant treatment of hormone responsive breast cancer. The positive effect on relapse risk reduction is well defined, but therapy is not free from bothersome side effects for which estrogen deprivation accounts to a great extent. Since endocrine therapy is usually prescribed for 5 years or longer to optimally display its protective effect, and because physical strain is missing, good tolerability and safety properties are important, particularly in low-risk patients. While tamoxifen has been the standard adjuvant endocrine treatment with well documented efficiency, it is increasingly replaced by third generation aromatase inhibitors due to their better effectiveness and tolerability. Because tamoxifen holds a risk for life-threatening adverse events such as endometrial cancer, pulmonary embolism, and stroke, its recommended duration of therapy is limited to 5 years, also because extension beyond that time did not produce a measurable advantage. While some side effects are present both with tamoxifen and aromatase inhibitors, differences in side effect profiles are well established. Although side effects of aromatase inhibitor-related therapy usually are mild and common to symptoms of menopause, misconception of the symptoms and their mechanism of action, as well as lack of knowledge about how to handle them, can easily lead to dangerous discontinuation of therapy.

Sural nerve harvesting beyond the popliteal region allows a significant gain of donor nerve graft length.

BACKGROUND: The sural nerve is the nerve most commonly used for peripheral nerve reconstruction. According to requirements for nerve graft length, it is dissected from the retromalleolar up to the popliteal region, where the main root of the sural nerve fibers, the medial sural cutaneous nerve, arises from the tibial nerve. It has been recommended to complete sural nerve harvesting below this area, to avoid damage to the tibial nerve. The aim of this study was to determine whether sural nerve fibers can be isolated from tibial and, more proximal, sciatic nerve fibers to gain more sural nerve graft length. METHODS: The sural nerve was dissected in 30 lower limbs. Anatomical characteristics such as the existence of a union forming the sural nerve, identification of the main root of sural nerve fibers, and the site of origin of the branch(es) forming the sural nerve were noted. Careful nerve preparation in the region of the sural nerve and its main root origin was conducted. RESULTS: In 18 specimens (60 percent), the authors found the classic formation of the sural nerve: the union of the medial sural cutaneous nerve and the peroneal communicating branch. The medial sural cutaneous nerve was the main root of sural nerve fibers in 28 of 30 cases (93 percent) and originated from the tibial nerve. Careful nerve preparation and epineurolysis beyond its anatomical origin allowed isolation and gain of sural nerve graft length of a median of 14 cm. CONCLUSION: In the authors' opinion, this is a feasible method of increasing the quantitative and qualitative outcome of sural nerve harvesting when greater length of sural nerve donor graft is needed for adequate nerve reconstruction.

Metal-on-metal hip implants: do they impair renal function in the long-term? A 10-year follow-up study.

INTRODUCTION: The aim of our study was to investigate a potential influence of elevated serumcobalt and serumchromiumlevels on renal function at minimum 10 years after implantation of a metal-on-metal hip. MATERIALS AND METHODS: Between November 1992 and June 1994 98 patients (44 m, 54 f) with an average age of 56 (22-79) years received a metal-on-metal bearing Metasul. At the time of the 10-year follow-up, 15 patients had died and 8 were lost to follow-up. The remaining 75 patients had laboratory analysis including serumcreatinine and full blood cell count as well as chromium and cobalt serum levels. RESULTS: Ten years postoperatively the median serumcreatinine level was 0.86 (0.55-1.51) mg/dl, the serumcreatinine clearance Ccr was in the normal range. The hemogram did not differ from that measured at the time of surgery. The median serumcobalt concentration was 0.75 (0.3-50.10) microg/l and the serumchromium concentration was 0.95 (0.3-58.6) mug/l, 10 years postoperatively. CONCLUSION: Our long-term data do not show any influence of serum cobalt or chromium concentrations on renal function following total hip arthroplasty.

A nonrandomized follow-up comparison between standard axillary node dissection and sentinel node biopsy in breast cancer.

INTRODUCTION: In many countries sentinel node biopsy (SNB) has become the standard of care in breast cancer based on a large number of observational studies but without results from prospective randomized trials. The goal of our study was to evaluate the oncological safety of the SNB in breast cancer in a multicenter, nonrandomized setting with comparable groups. PATIENTS AND METHODS: Between 1996/05 and 2004/11, 2942 patients from 14 departments in Austria with unicentric, unilateral, invasive disease without neoadjuvant therapy were collected in a database. The recommendations of the Austrian Sentinel Node Study Group were to complete a training period (phase I) with 50 cases of SNB followed by axillary lymph node dissection (ALND) to prove a detection rate of > or = 90% and a false-negative rate of < or = 5%. In the executing period (phase II), SNB was followed by ALND only if the sentinel node (SN) contained metastases. We compared the results on disease-free survival, local recurrence rates, distant recurrence rates and overall survival of both groups. Cases from phases I and II generated groups I (n=671) and 2 (n=2271 cases), respectively. RESULTS: Overall mean follow-up time: 34.41 months. CONCLUSION: SNB followed by ALND only in cases with metastases in the SN is a safe procedure and at least equal to ALND in all cases.

Breast-conserving surgery for T3/T4 breast cancer: an analysis of 196 patients.

INTRODUCTION: Breast conservation therapy (BCT) increases quality of life and self-esteem of breast cancer patients. In special cancer centers up to 90% of patients are treated with BCT. T3/T4 breast cancer is one of the few contraindications for BCT. However, retrospective data suggest that BCT may be eligible in selected cases of T3/T4 breast cancer. METHOD: We analyzed retrospectively 196 breast cancer patients (operated between 1995 and 2004) suffering from T3/T4 tumors and compared BCT and radiotherapy with mastectomy in these patients in terms of overall survival (OS), local recurrence free-survival (LRFS) and breast cancer-related death (BCRD). RESULT: Demographic data showed no significant differences in prognostic factors between patients treated with mastectomy compared with BCT. Kaplan-Meier curves demonstrated no significant difference for OS, LRFS and BCRD between the two groups. DISCUSSION: Our data strongly suggest that BCT with R0 resection followed by radiotherapy is feasible in patients with T3/T4 breast cancer. Prospective studies have to be performed to further investigate this issue.

Quality of life in GERD patients: medical treatment versus antireflux surgery.

Medical and surgical treatments are able to improve symptoms in patients with gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the outcome in GERD patients without therapy, under continuous medical treatment, and after laparoscopic antireflux surgery. Five hundred seventy-nine consecutive patients underwent medical or surgical treatment for GERD-induced symptoms. Patients were studied in detail before and after treatment by means of a symptom questionnaire, endoscopy, esophageal manometry, 24-hour esophageal pH monitoring, and a barium esophagogram. In addition, quality of life was measured by the means of the Gastrointestinal Quality of Life Index (GIQLI) and the Health-Related Quality of Life (HRQL) questionnaire. Surgery was indicated and performed in 351 patients with persistent or recurrent GERD symptoms and/or complications, and in patients preferring surgery to medical treatment, despite the use of an adequate medication. The remaining 228 patients were treated with proton pump inhibitors (PPI) in the standard dose, or if required, the double dose. The outcome was assessed 3 and 12 months after treatment. While symptoms and quality of life were highly impaired in GERD patients without therapy compared with normal people, a significant improvement was obtained by PPI therapy. Following surgery, quality of life was normalized in all subsections and was significantly higher compared with the medically treated group. These results stayed constant in short-term and intermediate follow-up. Medical and surgical therapies are both able to improve symptoms and quality of life in GERD patients. Nevertheless, the outcome is significantly better following surgery. It can be suggested that surgical treatment may be the more successful therapy in the long-term.

Preoperative core needle biopsy does not increase local recurrence rate in breast cancer patients.

OBJECTIVE: Several case reports and clinical studies in the literature demonstrate needle track seeding after core needle biopsy in patients with breast cancer in up to 50% of cases. The impact of this observation on local recurrence and overall survival rate is, however, not fully investigated. PATIENTS AND DESIGN: We retrospectively analysed 719 patients after breast conserving surgery and postoperative radiotherapy for stage I and II breast cancer. We divided this group into patients with (189) and without (530) preoperative core needle biopsy. Demographic data, local recurrence and overall survival rate were compared between these two groups. RESULT: Preoperative core needle biopsy did not significantly influence the local free recurrence rate (median follow-up time of 78 and 71 months, respectively). The prognostic factors and the postoperative therapy did not differ significantly between the two groups. CONCLUSION: Preoperative core needle biopsy seems to have no detrimental impact on local recurrence and overall survival after breast conserving surgery and postoperative radiotherapy.