Understanding the ant's unique biting system can improve surgical needle holders.

Mechanical grasping and holding devices depend upon a firm and controlled grip. The possibility to improve this gripping performance is severely limited by the need for miniaturization in many applications, such as robotics, microassembly, or surgery. In this paper, we show how this gripping can be improved in one application (the endoscopic needle holder) by understanding and imitating the design principles that evolution has selected to make the mandibles of an ant a powerful natural gripping device. State-of-the-art kinematic, morphological, and engineering approaches show that the ant, in contrast to other insects, has considerable movement within the articulation and the jaw´s rotational axis. We derived three major evolutionary design principles from the ant's biting apparatus: 1) a mobile joint axis, 2) a tilted orientation of the mandibular axis, and 3) force transmission of the adductor muscle to the tip of the mandible. Application of these three principles to a commercially available endoscopic needle holder resulted in calculated force amplification up to 296% and an experimentally measured one up to 433%. This reduced the amount of translations and rotations of the needle, compared to the needle's original design, while retaining its size or outer shape. This study serves as just one example showing how bioengineers might find elegant solutions to their design problems by closely observing the natural world.

GAB1::ABL1 fusions define a distinctive soft tissue neoplasm, with variable perineurial differentiation, and a predilection for children and young adults.

Although well known as a fusion partner in hematological malignancies, fusion genes involving the ABL proto-oncogene 1 (ABL1), mapping to chromosomal region 9q34.12, have only been anecdotally reported in five soft tissue tumors. These neoplasms have been variously reported as perineurioma, angiofibroma, and solitary fibrous tumor, and all have harbored a GAB1::ABL1 gene fusion; however, the nosology and clinicopathological characteristics of soft tissue tumors carrying this rare fusion have not been delineated. We herein describe eight tumors containing the GAB1::ABL1 fusion and review previously reported cases in a series to define their morphological spectrum, address immunohistochemical evidence for a line of differentiation, with special reference to the presence or absence of a perineurial immunophenotype, and gather insight into their behavior. The patients included four females and four males, aged 13-37 years (median, 24 years). Two cases each originated in the shoulder area, trunk, hands, and lower extremities, with a size range of 1.5-8 cm (median, 3.4 cm). Four tumors were deep and four superficial. All tumors were morphologically similar, being composed of bland fibroblast-like spindle to ovoid cells diffusely arranged in a paucivascular fibrous to fibromyxoid stroma with variable resemblance to soft tissue perineurioma. Mitotic activity was generally low (0-8 mitoses in 10 high-power fields [HPFs]; median, 1). All lesions had at least focally infiltrative margins, but they otherwise lacked pleomorphism and necrosis. Immunohistochemistry showed focal reactivity for CD34 (5/7), epithelial membrane antigen (EMA) (3/8), claudin1 (2/3), GLUT1 (4/6), and S100 (2/7); other markers, including MUC4 (0/7), desmin (0/9), and smooth muscle actin (SMA) (0/4), were negative. RNA sequencing revealed a GAB1::ABL1 fusion in all cases with exon 6 of GAB1 fused to exon 2 of ABL1. Treatments included various forms of surgical intervention in seven cases; one tumor was biopsied only. Limited follow-up was available for five patients. One tumor regrew rapidly within 1 month to 1.5 cm after an initial marginal excision and was re-excised with close margins. Four patients were disease-free at 1, 3, 14, and 25 months of follow-up. Metastases have not, to date, been observed. This series characterizes "GAB1::ABL1 fusion-positive spindle cell neoplasm" as a distinct entity, with overlapping features with soft tissue perineurioma and predilection for children and young adults.

Operating lists are created by rational algorithms and use of power. What can a social scientific view offer surgeons?

PURPOSE: Algorithms for surgical operation planning are evidence-based. However, choices sometimes have to be made between medically equal solutions e.g. for staffing of sought-after operations. Such decisions are heavily influenced by micropolitics and power. The article examines the array of highly manipulated processes around operation theatre allocation of convenient time slots or staff, which play out in various ways in all of the world's main regional surgical cultures. METHOD: Essay supported by empiric data from an ethnographic power-analysis targeted to senior executive surgeons. Operations were categorized into "Interesting" (i.e. career-promoting) and "Uninteresting" (i.e. routine) operations. RESULTS: Fifty nine executives responded. Only one respondent contested the categorization of operations into Interesting and Uninteresting. The two categories were staffed according to significantly different criteria (p < 0.05). These were classified as Rational (e.g. "surgical expertise"), Social (e.g. "equity"), and Political (e.g. "status"). For Interesting operations, Rational criteria were deemed most relevant, while for the Uninteresting operations "equity" was ranked top. Moreover, we found significant differences between surgeons' and external observers' (experienced clerical and nursing staff) assessments of staffing decisions, the latter ranking Political motives higher. Decisions were almost exclusively negotiated among surgeons. 33% of respondents said they used subterfuges such as withholding information, incorrect duration-statements, and barter arrangements to defuse possible conflicts. CONCLUSIONS: Operating Lists are not merely the product of rational resource optimization. This article demonstrates the methodic feasibility of academic investigation into the typically tacit micro-political mechanisms in List-making. Developing such research further may potentially concern the practice and outcome of surgery.

Absence of Maternal Microchimerism in Regional Lymph Nodes of Children With Biliary Atresia.

OBJECTIVE: Maternal lymphocytes have been cited as a potential cause of infantile biliary atresia (BA). When hepatoportoenterostomy is performed, locoregional lymphadenopathy is frequently encountered. METHODS: We screened enlarged nodes from 6 consecutive nonsyndromatic BA patients (age: 68 days ±â€Š18.9 days) for maternal elements using DNA fingerprinting with short tandem repeat analysis and quantitative real-time polymerase chain reaction for allelic (single nucleotide) sequence polymorphisms. RESULTS: Although being partly positive in infants' peripheral blood, no maternal microchimerism could be demonstrated in any of the lymph nodes. CONCLUSION: This result challenges the hypothesis that maternal cells play a role in hilar lymphadenopathy of children with BA.

A noise-reduction program in a pediatric operation theatre is associated with surgeon's benefits and a reduced rate of complications: a prospective controlled clinical trial.

OBJECTIVE: We assessed the impact of a noise-reduction program in a pediatric operating theatre. BACKGROUND: Adverse effects from noise pollution in theatres have been demonstrated. METHODS: In 156 operations spatially resolved, sound levels were measured before and after a noise-reduction program on the basis of education, rules, and technical devices (Sound Ear). Surgical complications were recorded. The surgeon's biometric (saliva cortisol, electrodermal activity) and behavioral stress responses (questionnaires) were measured and correlated with mission protocols and individual noise sensitivity. RESULTS: Median noise levels in the control group versus the interventional group were reduced by -3 ± 3 dB(A) (63 vs 59 dB(A), P < 0.001) with a grossly decreased number of peaks greater than 70 dB(A) (Δn = -61/hour, P < 0.01). The intervention significantly reduced non-operation-related noise. The incidence of postoperative complications was significantly lower in patients of the intervention group (n = 10/56 vs 20/58 control; P < 0.05). "Responders," surgeons with an above-average noise sensitivity (correlation r = -0.6 for the work subscale of the NoiseQ questionnaire, P < 0.05), experienced improved intrateam communication, a decrease in disturbing conversations and sudden noise peaks (P < 0.05). Biometrically, the intervention decreased both the surgeon's pre- to postoperative rise in cortisol by approximately 20% and the surgeon's electrodermal potentials of greater than 15 µS, indicating severe stress by 60% (P > 0.05). CONCLUSIONS: Spontaneous noise during pediatric operations attains the magnitude of a lawn mower and peaks resemble a passing truck. The sound intensity could be reduced by 50% by specific measures. This reduction was associated with a significantly lowered number of postoperative complications. The surgeon's benefits are idiosyncratic with "responders" experiencing marked improvements.

Survival with the native liver after laparoscopic versus conventional kasai portoenterostomy in infants with biliary atresia: a prospective trial.

OBJECTIVE: A prospective study to compare survival with own liver in laparoscopic versus conventional Kasai portoenterostomy in patients with biliary atresia. BACKGROUND: Available studies on laparoscopic versus conventional Kasai portoenterostomy focus on short-term results, include small numbers of patients and have design limitations. METHODS: A consecutive series of patients underwent laparoscopic Kasai procedure from 2006 to 2007. Conventionally operated control patients consisted of a consecutive series of infants with biliary atresia operated from August 2003 to 2006. All data were ascertained prospectively using the European Biliary Atresia Registry/EBAR registration forms. Primary outcome measure was survival with own liver 6 months after Kasai without being listed for liver transplantation. An interim analysis was planned after data became available for the first 12 patients, who underwent the laparoscopic Kasai procedure. In case of a significantly different interim outcome, the follow-up period should be extended to 24 months until a final decision can be made. RESULTS: Twelve infants underwent laparoscopic Kasai procedure without conversion or revision and there was no revision in the control group of 28 conventionally operated patients. Six months after operation, 5 of 12 laparoscopically operated patients (42%) survived with own liver, compared with 23 of 28 (82%) controls (P < 0.01). The study was stopped due to the significantly higher rate of liver transplantation after laparoscopic operation. Ten patients (83%) after laparoscopic Kasai versus 18 (64%) conventionally operated patients were transplanted after 24 months (P < 0.05) and survival rates with own liver and serum bilirubin <20 µmol/L were 1 (8%) versus 8 (29%), respectively (P < 0.05). CONCLUSIONS: This prospective study shows that the laparoscopic Kasai procedure for biliary atresia is technically feasible. However, the study was stopped after inclusion of 12 laparoscopically operated infants due to a lower survival with the native liver after laparoscopic versus conventional Kasai operation. Superior results after conventional operation were confirmed at follow-up after 24 months. Study registration ID: EBAR 9260/NCT01063699.

Effects of intraoperative breaks on mental and somatic operator fatigue: a randomized clinical trial.

BACKGROUND: Intermittent work breaks are common in fields with high workload but not yet for surgeons during operations. We evaluated the effects of intraoperative breaks during complex laparoscopic surgery (5 min every half hour) on the surgeon. METHODS: Fifty-one operations were randomized to a scheme with intraoperative breaks and release of the pneumoperitoneum (intermittent pneumoperitoneum (IPP)) or conventional conduct (CPP). Stress hormones and α-amylase were determined in the surgeon's saliva pre-, intra-, and postoperatively. Mental performance and error scores, musculoskeletal strain, and continuous ECG were secondary endpoints. RESULTS: Regular intraoperative breaks did not prolong the operation (IPP vs. CPP group: 176 vs. 180 min, p > 0.05). The surgeon's cortisol levels during the operation were reduced by 22 ± 10.3% in the IPP vs. the CPP group (p < 0.05). There were significantly fewer (p < 0.05) intraoperative events in the IPP vs. the CPP group, which yielded higher α-amylase peaks. The pre- to postoperative increase in the error rates of the bp-concentration test was fourfold reduced in the IPP group (p = 0.052). The relevant locomotive strain-scores were grossly reduced by IPP (p < 0.001). CONCLUSIONS: Our data support the idea that work breaks during complex laparoscopic surgery can reduce psychological stress and preserve performance without prolongation of the operation time compared with the traditional work scheme.

Laparoscopic anterior hemifundoplication improves key symptoms without impact on GE in children with and children without neurodevelopmental delays.

AIM: We investigated the impact of laparoscopic anterior hemifundoplication on gastric emptying (GE) and specific symptoms in children with and children without neurodevelopmental delays gastroesophageal reflux. Scintigraphic and ultrasonographic GE measurements were correlated. PATIENTS AND METHODS: Twenty-six children (mean age 7 ± 6.1 years), of whom 14 were neurodevelopmentally delayed, were evaluated prospectively before 3 and 6 months after laparoscopic anterior hemifundoplication. All of the patients underwent clinical assessments, interviews, and 24-hour pH monitoring. Key symptoms were evaluated using a 5-point Likert scale. Gastric emptying was assessed by Tc-99m-DTPA-scintigraphy and ultrasonography. RESULTS: All of the children had significant catch-up growth after fundoplication, which was more pronounced in the neurologically normal children (P < 0.05 vs impaired), in line with a decrease in the use of omeprazol (mean 0.93 ± 0.7 mg · kg(-1) · day(-1) before and 0.06 ± 0.18 mg · kg(-1) · day(-1) at 6 months after operation; P < 0.001). The 24-hour pH monitoring normalized in all of the children, and the mean severity of the key symptoms such as vomiting, choking, and pain was significantly reduced (P < 0.001). Scintigraphic GE parameters, such as the elimination rate/minute, gastric half-emptying time (t1/2), gastric residual activity (RA), and duration of the initial merging time, were not altered significantly by the operation (P > 0.05). Ultrasonographic evaluations confirmed these results [positive correlation with scintigraphy for t1/2 (P = 0.006) and RA (P = 0.01)]. The symptoms evolution and GE were uncorrelated (P > 0.01). There were no significant differences between children with and children without neurodevelopmental delays. CONCLUSIONS: Laparoscopic anterior hemifundoplication achieves an excellent symptomatic outcome without affecting GE in children with and children without neurodevelopmental delays.

Impact of laparoscopic anterior 270 degrees fundoplication on the quality of life and symptoms profile of neurodevelopmentally delayed versus neurologically unimpaired children and their parents.

BACKGROUND: This prospective study investigated the therapy-induced changes in the quality of life (QoL) experienced by neurologically healthy and neurodevelopmentally delayed children and their parents after laparoscopic anterior 270 degrees fundoplication (LAF). METHODS: In this study, 40 patients (21 impaired) with a mean age of 7.8 years underwent LAF for gastroesophageal reflux disease (GERD) and were evaluated before surgery and then 3 and 6 months afterward using the Gastrointestinal Quality-of-Life Index (GIQLI) supplemented by conventional symptom markers. RESULTS: Growth, proton pump inhibitor use, and frequency of supraesophageal/respiratory symptoms improved significantly (p < 0.001) as did feeding parameters (p < 0.05). The global GIQLI score improved by 49 +/- 21% (p < 0.001). The greatest improvement occurred in the symptoms domain (p < 0.001). However, positive alterations also were found in the dimensions of emotions (58%), social functions (37%) and physical functions (27%) (p < 0.001). Comparison of the overall benefit did not show any differences between the subgroups of neurologically fit and impaired children. However, for the child-centered symptoms domain, the benefit increased stepwise with the degree of impairment. This was counterbalanced by an inverse relationship for the parent-centered emotions domain (p < 0.05). CONCLUSIONS: Besides the known improvement in symptoms, LAF achieves a significant improvement in QoL for children and their parents. There is no overall difference in the benefit experienced by neurologically impaired and healthy children.

Advancing the integration of hospital IT. Pitfalls and perspectives when replacing specialized software for high-risk environments with enterprise system extensions.

BACKGROUND: Planning and controlling surgical operations hugely impacts upon productivity, patient safety, and surgeons' careers. Established, specialized software for this task is being increasingly replaced by "Operating Room (OR)-modules" appended to enterprise-wide resource planning (ERP) systems. As a result, usability problems are re-emerging and require developers' attention. OBJECTIVE: Systematic evaluation of the functionality and social repercussions of a global, market-leading IT business control system (SAP R3, Germany), adapted for real-time OR process steering. METHODS: Field study involving document analyses, interviews, and a 73-item survey addressed to 77 qualified (> 1-year system experience) senior planning executives (end users; "planners") working in surgical departments of university hospitals. RESULTS: Planners reported that 57% of electronic operation requests contained contradictory information. Key screens contained clinically irrelevant areas (36 +/- 29%). Compared to the legacy system, users reported either no improvements or worse performance, in regard to co-ordination of OR stakeholders, intra-day program changes, and safety. Planners concluded that the ERP-planning module was "non-intuitive" (66%), increased planning work (56%, p=0.002), and did not impact upon either organizational mishap spectrum or frequency. Interviews evidenced intra-institutional power shifts due to increased system complexity. Planners resented e.g. a trend towards increased personal culpability for mishap. CONCLUSIONS: Highly complex enterprise system extensions may not be directly suited to specific process steering tasks in a high risk/low error-environment like the OR. In view of surgeons' high primary task load, the repeated call for simpler IT is an imperative for ERP extensions. System design should consider a) that current OR IT suffers from an input limitation regarding planning-relevant real-time data, and b) that there are social processes that strongly affect planning and particularly ERP use beyond algorithms. Real improvement of clinical IT tools requires their independent evaluation according to standards developed for pharmaceutical subjects.

Importance, mechanisms and limitations of the distant bystander effect in cancer gene therapy of experimental liver tumors.

GCV-ablation of transplanted TK-positive liver tumors or the application of syngenic and allogenic HSV-TK/GCV oncolysates significantly reduced the size of synchronously growing untreated sister tumors in the liver. These TK-negative liver tumors constantly showed an increased infiltration by mononuclears (x4). The relative abundance of CD 4/8, NK and monocyte subtypes remained constant. The distant bystander effect was associated with a strong induction of GMCSF and IL-12 expression in the untreated TK-negative liver tumors. Analysis of the vbeta T-cell receptor profiles from TK-negative tumors did not point to clonal lymphocyte expansions. These results support the view of the 'distant bystander effect' as a predominantly local phenomenon, which is mediated by resident immune effectors rather than by MHC I restricted CD 3 positive lymphocytes.

Work breaks during minimally invasive surgery in children: patient benefits and surgeon's perceptions.

INTRODUCTION: We recently reported that 5-minute work breaks every 25 minutes during long lasting laparoscopy in children (intermittent pneumoperitoneum [IPP] scheme) decrease the surgeon's stress markers such as saliva cortisol and heart rate and improve time-concentration scores significantly. Data on the impact of breaks on the patient and on the surgeon's perception of breaks, however, are still lacking. MATERIALS AND METHODS: We present the comprehensive biometry data of a randomized trial including 26 patients operated with (IPP) and 26 patients without breaks (continuous pneumoperitoneum [CPP]). Moreover, we analyzed the surgeon's perception of the break scheme using behaviorally anchored 10-point rating scales. RESULTS: There were no significant intergroup differences in the pooled patients' hemodynamics including cardiac output, blood gas readings, and temperature during and after the operation. Infants <1 year of age undergoing IPP versus CPP produced significantly higher urine volumes (1.60 ± 1.8 vs. 0.67 ± 1.00 mL/h/m2, p < 0.05). The overall area under the curve (AUC) of their cardiac output was 106.7 ± 41.1 (IPP) versus 78.0 ± 41.3 (CPP). This difference became significant during long operations (p < 0.05 for AUC 150 to 270 minutes). Surgeon's break perception and acceptance: team communication shifted from an implicit "mute communication" to an explicit way "issues are outspoken" by +4.7 ± 2.6 (p < 0.05) with improved coherence between operator and assistants (+3.9 ± 2.1). However, when questioned whether there was one particular welcome (5.1 ± 1) or extremely disturbing (6.4 ± 2.4) break during the entire procedure, the latter yielded a higher score (p > 0.05). Acceptance varied according to the surgeon's own esteem of his/her work style. Operators with high self-ratings for "fast" were inclined to put up with shorter breaks ("fast" vs. "slow" = 3.5 ± 1.4 vs. 5.5 ± 0.7, p < 0.05). Overall the scheme was approved (5.9 ± 3.2). CONCLUSIONS: A break scheme has no detrimental effect on patient physiology and is beneficial in infants. It needs careful tailoring to both the surgeon's work situation and self-esteem to gain acceptance.

Minimally-invasive pediatric surgery in 2004: a survey including 50 German institutions.

BACKGROUND: A survey on the practice of laparoscopic and thoracoscopic surgery in pediatric surgical departments in Germany is presented. MATERIALS AND METHODS: A questionnaire was sent to all 71 pediatric surgical departments in Germany (population 82 million). Fifty institutions (70%) took part in the survey that mainly included data for the year 2004: spectrum of minimally invasive operations, quantity of procedures, conversions, major complications, number of performing surgeons and residents. RESULTS: Laparoscopic techniques were used in 48 departments (96%) and thoracoscopic techniques in 37 (74%). The annual frequency of laparoscopies was less than 100 in 30 departments (62%) and more than 100 in 15 (31%). The number of thoracoscopies was less than 50 in 35 departments (73%) and more than 50 in 2 (4%). Appendectomy was offered in 45 (90%), varicocelectomy in 32 (64%), and Fowler-Stephens operation in 33 (66%). Twenty-one departments (42%) covered more advanced procedures such as laparoscopically assisted pull-through for Hirschsprung disease. Most demanding procedures such as laparoscopic choledochal cyst resection, duodeno-duodenostomy, heminephrectomy, or pyeloplasty were offered by 10 departments (20%). Minimally invasive surgery was performed by 1 surgeon (12%) in 6 institutions and by more than 5 surgeons (14%) in 7 institutions. CONCLUSION: Minimally invasive techniques are increasingly accepted in most German pediatric surgical institutions for a wide range of indications. However, the number of departments offering major minimally invasive procedures remains limited.