Supervised classification of minimally invasive surgery psychomotor competence based on instruments motion analysis

Background Objective assessment of psychomotor skills has become an important challenge in the training of minimally invasive surgical (MIS) techniques. Currently, no gold standard defining surgical competence exists for classifying residents according to their surgical skills. Supervised classification has been proposed as a means for objectively establishing competence thresholds in psychomotor skills evaluation. This report presents a study comparing three classification methods for establishing their validity in a set of tasks for basic skills’ assessment. Methods Linear discriminant analysis (LDA), support vector machines (SVM), and adaptive neuro-fuzzy inference systems (ANFIS) were used. A total of 42 participants, divided into an experienced group (4 expert surgeons and 14 residents with >10 laparoscopic surgeries performed) and a nonexperienced group (16 students and 8 residents with <10 laparoscopic surgeries performed), performed three box trainer tasks validated for assessment of MIS psychomotor skills. Instrument movements were captured using the TrEndo tracking system, and nine motion analysis parameters (MAPs) were analyzed. The performance of the classifiers was measured by leave-one-out cross-validation using the scores obtained by the participants. Results The mean accuracy performances of the classifiers were 71 % (LDA), 78.2 % (SVM), and 71.7 % (ANFIS). No statistically significant differences in the performance were identified between the classifiers. Conclusions The three proposed classifiers showed good performance in the discrimination of skills, especially when information from all MAPs and tasks combined were considered. A correlation between the surgeons’ previous experience and their execution of the tasks could be ascertained from results. However, misclassifications across all the classifiers could imply the existence of other factors influencing psychomotor competence.

Avaliação dos biomarcadores urinários no controle do tratamento de estenose de junção ureteropélvica em adultos

INTRODUÇÃO E OBJETIVO: A estenose de junção ureteropélvica (EJUP) é importante causa de obstrução do trato urinário e pode levar a deterioração progressiva da função renal. Há espaço para o aprimoramento de novos métodos diagnósticos capazes de discriminar hidronefrose e uropatia obstrutiva. Acredita-se que os biomarcadores urinários podem fornecer indícios de lesão renal precoce na obstrução urinária. Neste contexto, KIM-1 pode elevar-se na urina por lesão tubular proximal, NGAL por lesão no túbulo proximal, distal ou alça de Henle, CA19-9 por produção excessiva no túbulo obstruído e ?2-microglobulina (beta2M) por injúria ao glomérulo ou ao túbulo proximal. O objetivo do presente estudo foi avaliar as propriedades diagnósticas dos biomarcadores urinários citados em adultos com EJUP, sendo o primeiro estudo na literatura a avaliar tais moléculas nesta população. MÉTODOS: Foram estudados de modo prospectivo pacientes consecutivos acima de 18 anos com diagnóstico de EJUP submetidos a pieloplastia videolaparoscópica de dezembro de 2013 a fevereiro de 2015. Foram excluídos do estudo pacientes com EJUP bilateral, rim contralateral patológico, EJUP em rim único, antecedentes de tratamento cirúrgico para estenose de JUP ou taxa de filtração glomerular inferior a 60 ml/min/1,73m2. Cada paciente forneceu quatro amostras de urina para medição de biomarcadores, uma no pré-operatório e outras com 1, 3 e 6 meses de seguimento pós-operatório. O grupo controle foi constituído por voluntários saudáveis sem hidronefrose à ultrassonografia. RESULTADOS: Foram incluídos 47 pacientes com idade média de 38,6 ± 12,7 anos (intervalo 19 a 64 anos), sendo 17 (36,2%) do sexo masculino e 30 (62,8%) do sexo feminino. O grupo controle foi composto por 40 indivíduos semelhantes ao grupo com EJUP no que concerne idade (p = 0,95) e sexo (p = 0,82). KIM-1 foi o marcador com melhores propriedades diagnósticas, apresentando área sob a curva (AUC) de 0,79 (95% CI 0,70 a 0,89). O NGAL, por sua vez, teve AUC de 0,71 (95% CI 0,61 a 0,83), CA19- 9 teve AUC de 0,70 (95% CI 0,60 a 0,81) e (beta2M) apresentou AUC de 0,61 (95% CI 0,50 a 0,73), sendo o único biomarcador com propriedades inadequadas neste cenário. O KIM-1 foi o marcador mais sensível com o ponto de corte 170,4 pg/mg de creatinina (sensibilidade 91,4%, especificidade 59,1%) e o CA 19-9 o mais específico para o ponto de corte de 51,3 U/mg de creatinina (sensibilidade 48,9%, especificidade 88,0%), enquanto o NGAL foi o que apresentou maior queda após desobstrução, com 90,0% dos pacientes apresentando clareamento superior a 50%. CONCLUSÕES: A avaliação dos biomarcadores urinários é útil no diagnóstico de obstrução em adultos com EJUP submetidos a pieloplastia videolaparoscópica. O KIM-1 foi o marcador mais sensível e o CA 19-9 o mais específico, enquanto o NGAL foi o que apresentou maior que com a desobstrução. Houve queda das concentrações dos marcadores após pieloplastia no período estudado. O papel exato dos biomarcadores urinários no cenário de obstrução em adultos deve ser mais amplamente investigado

Pro-fibrotic polymorphisms predictive of advanced liver fibrosis in the severely obese

Background/Aims: Insulin resistance and systemic hypertension are predictors of advanced fibrosis in obese patients with non-alcoholic fatty liver disease (NAFLD). Genetic factors may also be important. We hypothesize that high angiotensinogen (AT) and transforming growth factor-beta1 (TGF-beta1) producing genotypes increase the risk of liver fibrosis in obese subjects with NAFLD. Methods: One hundred and five of 130 consecutive severely obese patients having a liver biopsy at the time of laparoscopic obesity surgery agreed to have genotype analysis. Influence of specific genotype or combination of genotypes on the stage of hepatic fibrosis was assessed after controlling for known risk factors. Results: There was no fibrosis in 70 (67%), stages 1-2 in 21 (20%) and stages 3-4 fibrosis in 14 (13%) of subjects. There was no relationship between either high AT or TGF-beta1 producing genotypes alone and hepatic fibrosis after controlling for confounding factors. However, advanced hepatic fibrosis occurred in five of 13 subjects (odds ratio 5.7, 95% confidence interval 1.5-21.2, P = 0.005) who inherited both high AT and TGF-beta1 producing polymorphisms. Conclusions: The combination of high AT and TGF-beta1 producing polymorphisms is associated with advanced hepatic fibrosis in obese patients with NAFLD. These findings support the hypothesis that angiotensin II stimulated TGF-beta1 production may promote hepatic fibrosis. (C) 2003 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Histological analysis of gallbladder diseases in relation to opisthorchiasis in endemic areas of Thailand

Chronic gallbladder disease frequently accompanies infection with the liver fluke, Opisthorchis viverrini, in Northeast Thailand. However, the pathology and pathogenesis of the gallbladder disease have not been described. Accordingly, gallbladder specimens from 187 consecutive patients who had undergone cholecystectomy at a referral hospital in an endemic area in Thailand were histologically characterized in relation to O. viverrini infection. The infection was assessed by the presence of parasite eggs in the bile and/or antibody response to the liver fluke. The average level of parasite-specific IgG was significantly higher in patients with Opisthorchis eggs in the bile than those without (P < 0.001). The main histopathologic features of the gallbladder included inflammation, mucosal atrophy/or hyperplasia, goblet cell metaplasia, mucous gland hyperplasia, Rokitansky-Aschoff sinus formation, dysplasia and fibrosis. The fibrosis was strongly associated with elevated levels of Opisthorchis-specific antibody (P < 0.001) but not with the presence of parasite eggs. Other pathologic features did not vary in frequency or severity with parasitological status. Our results show that severe fibrosis of the gallbladder is a more common histologic feature of cholecystitis among those with O. viverrini infection compared to those without infection. The close relationship between parasite-specific IgG and severe fibrosis suggests that specific immune response to the parasite play an important role in the pathogenesis of the fibrotic change. (C) 2003 Elsevier B.V. All rights reserved.

Primary aldosteronism - careful investigation is essential and rewarding

Once considered rare, primary aldosteronism (PAL) is now regarded as the commonest potentially curable and specifically treatable form of hypertension. At Greenslopes Hospital Hypertension Unit (GHHU), the decision in 1991 to screen all (and not just hypokalemic or resistant) hypertensives by aldosterone/renin ratio (ARR) testing led to a 10-fold increase in detection rate of PAL and four-fold increase in removal rate of aldosterone-producing adenomas (APAs). The GHHU/Princess Alexandra Hospital Hypertension Unit PAL series stands at 977 patients and 250 APAs removed with hypertension cured in 50-60% (remainder improved). Reliable detection requires that interfering medications are withdrawn (or their effects considered) before ARR measurement, and reliable methods (such as fludrocortisone suppression testing) to confirm PAL. Adrenal venous sampling is the only dependable way to differentiate APA from bilateral adrenal hyperplasia. Genetic testing has facilitated detection of alucocorticoid-remediable, familial PAL. Identification of mutations causing the more common familial variety described by GHHU in 1991 should further aid in detection of PAL. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Selective approach for transperitoneal and extraperitoneal endoscopic nephrectomy in children

Purpose: From the experience of a large combined series of transperitoneal. (TP) and retroperitoneal (RP) endoscopic complete and partial nephroureterectornies in children, we present a logical selective endoscopic approach to benign renal pathology. Materials and Methods: During a 5-year period 122 complete nephrectomies and nephroureterectomies (bilateral 2, invisible ectopic 8) and 63 partial nephroureterectomies for duplex (52 upper, 8 lower) or singleton polar disease (xanthogranulomatous pyelonephritis 1, cyst 2) were performed. Of the partial nephrectomies, ureterectomy, bladder repair and lower moiety reimplantation were performed in 8. Patient age ranged from 2.7 months to 14 years (mean 2.9 years). Preoperative weight ranged from 2.7 to 98 kg (mean 12.3). The position of the renal remnant, the presence or absence of a refluxing ureter and the need for ureterectomy were the major determining factors affecting choice of endoscopic approach. Results: A total of 179 (96.7%) procedures were successfully completed endoscopically. The 6 open conversions (3.2%) occurred early in our experience. The operating time reflected the complexity of the excision and lower urinary reconstruction (lateral and posterior RP 25 to 145 minutes [mean 921) TP with ureterocelectomy and bladder neck repair 105 to 355 minutes [mean 153]. Hospital stay for RP and simple TP was 1.5 days (mean 1 to 4) and for complicated TP 2 to 8 days (mean 3.5). Conclusions: We suggest a posterior retroperitoneal approach with isolated renal excision without extended ureterectomy. The lateral retroperitoneal approach allows complete ureterectomy as well as better exposure to horseshoe and pelvic kidneys and, therefore, avoids exposure to intraperitoneal. structures. Finally, the transperitoneal approach is recommended when complete moiety excision with lower urinary reconstruction is anticipated.

Laparoscopically-assisted resection rectopexy for rectal prolapse: Ten years' experience

PURPOSE: This study has been undertaken to audit a single-center experience with laparoscopically-assisted resection rectopexy for full-thickness rectal prolapse. The clinical Outcomes and long-term results were evaluated. METHODS: The data were prospectively collected for the duration of the operation, time to passage of flatus postoperatively, hospital stay, morbidity, and mortality. For follow-up, patients received a questionnaire or were contacted. The data were divided into quartiles over the study period, and the differences in operating time and length of hospital stay were tested using the Kruskal-Wallis test. RESULTS: Between March 1992 and October 2003, a total of 117 patients underwent laparoscopic resection rectopexy for rectal prolapse. The median operating time during the first quartile (representing the early experience) was 180 minutes compared with 110 minutes for the fourth quartile (Kruskal-Wallis test for operating time = 35.523, 3 df, P < 0.0001). Overall morbidity was 9 percent (ten patients), with one death (< 1 percent). One patient had a ureteric injury requiring conversion. One minor anastomotic leak Occurred, necessitating laparoscopic evacuation of a pelvic abscess. Altogether, 77 patients were available for follow-up. The median follow-up was 62 months. Eighty percent of the patients reported alleviation of their symptoms after the operation. Sixty-nine percent of the constipated patients experienced an improvement in bowel frequency. No patient had new or worsening symptoms of constipation after Surgery. Two (2.5 percent) patients had full-thickness rectal prolapse recurrence. Mucosal prolapse recurred in 14 (18 percent) patients. Anastomotic dilation was performed for stricture in five (4 percent) patients. CONCLUSIONS: Laparoscopically-assisted resection rectopexy for rectal prolapse provides a favorable functional outcome and low recurrence rate. Shorter operating time is achieved with experience. The minimally invasive technique benefits should be considered when offering rectal prolapse patients a transabdominal approach for repair, and emphasis should now be on advanced training in the laparoscopic approach.

Minimally Invasive Approach of a Retrocaval Ureter

The retrocaval ureter is a rare congenital entity, classically managed with open pyeloplasty techniques. The experience obtained with the laparoscopic approach of other more frequent causes of ureteropelvic junction (UPJ) obstruction has opened the method for the minimally invasive approach of the retrocaval ureter. In our paper, we describe a clinical case of a right retrocaval ureter managed successfully with laparoscopic dismembered pyeloplasty. The main standpoints of the procedure are described. Our results were similar to others published by other urologic centers, which demonstrates the safety and feasibility of the procedure for this condition.

Influence of laparoscopy and laparotomy on gasometry, leukocytes and cytokines in a rat abdominal sepsis model

Laparoscopic surgery is associated with reduced surgical trauma, and less acute phase response, as compared with open surgery. Cytokines are important regulators of the biological response to surgical and anesthetic stress. The aim of this study was to determine if CO2 pneumoperitoneum would change cytokine expression, gas parameters and leukocyte count in septic rats. Methods: Wistar rats were randomly assigned to five groups: control (anesthesia only), laparotomy, CO2 pneumoperitoneum, cecum ligation and puncture by laparotomy, and laparoscopic cecum ligation and puncture. After 30 min of the procedures, arterial blood samples were obtained to determine leukocytes subpopulations by hemocytometer. TNFα, IL-1β, IL-6 were determined in intraperitoneal fluid (by ELISA). Gas parameters were measured on arterial blood, intraperitoneal and subperitoneal exsudates. Results: Peritoneal TNFα, IL-1β and IL-6 concentrations were lower in pneumoperitoneum rats than in all other groups (p<0.05). TNFα, IL-1β and IL-6 expression was lower in the laparoscopic than in laparotomic sepsis (p<0.05). Rats from laparoscopic cecum ligation and puncture group developed significant hypercarbic acidosis in blood and subperitoneal fluid when compared to open procedure group. Total white blood cells and lymphocytes were significantly lower in laparoscopic cecum ligation and puncture rats than in the laparotomic (p<0.01). Nevertheless, the laparotomic cecum ligation rats had a significant increase in blood neutrophils and eosinophils when compared with controls (p<0.05). Conclusions: This study demonstrates that the CO2 pneumoperitoneum reduced the inflammatory response in an animal model of peritonitis with respect to intraperitoneal cytokines, white blood cell count and clinical correlates of sepsis. The pneumoperitoneum produced hypercarbic acidosis in septic animals

Small bowel adenocarcinoma. Two case reports

Introduction. Small bowel adenocarcinoma is a rare tumor, with a still not well studied tumorigenesis process, and non-specific symptoms that cause a delay in the diagnosis and consequently a worst outcome for the patient. Videocapsule endoscopy (VCE) and double-balloon enteroscopy (DBE) have revolutionized the diagnosis and management of patients with small bowel diseases. Surgery is the treatment of choice when feasible, while the chemotherapeutic approach is still not well standardized. Case reports. Two cases in 2 months (two women 52 and 72-yr-old) of primary bowel adenocarcinoma is reported. The site of the tumor was in jejunum, instead of the most common site in duodenum. The patients underwent DBE with biopsy and ink mark. Laparoscopic-assisted bowel segmental resection was performed. The pathologic diagnosis was primary jejunum adenocarcinoma. No post-operative mortality or significant morbidities were noted. Conclusion. The combination of DBE and laparocopic-assisted bowel surgery represents an ideal diagnostic and therapeutic method.

Is there a role of percutaneous drainage in non-parasitic splenic cysts? Case report

Pathogenesis, classification and treatment of non-parasitic splenic cysts (NPSCs) are controversial. The utility of percutaneous aspiration of the cyst is not well understood. We report a case of a 32 year-old woman with a symptomatic giant epidermoid cyst of the spleen treated with laparoscopic splenectomy. A percutaneous transcatheter drainage was performed under ultrasound guidance before surgical procedure in order to classify the type of cyst and to choose the best treatment.

Sistema de realidade aumentada no procedimento cirúrgico de remoção de pedras nos rins

A inovação tecnológica e as facilidades que gera tem tido um impacto crescente em diversas área, inclusivamente na medicina. A rápida evolução por parte de algumas tecnologias, como é o caso da Realidade Aumentada (RA), criam excelentes oportunidades, nomeadamente para intervenções cirúrgicas laparoscópicas, que apresentam especialmente problemas ao nível da exposição do doente a radiação. O presente documento detalha todo o processo de investigação e desenvolvimento realizado com a pretensão de criar um sistema de navegação por RA que auxilie o procedimento cirúrgico laparoscópico de remoção de pedras nos rins. Com este objetivo em perspetiva, e numa parceria com a empresa ECmedica LTD, foram desenvolvidos quatro protótipo funcionais. Com o intuito de compreender as melhores práticas de sistemas de input, interface e sistema de registo a aplicar, estes integraram aspetos inovadores tais como a utilização de uma sonda ultra-som, como substituta do raioX, e um registo feito através de sensores magnéticos. Apoiados numa metodologia de design centrado no utilizador e em instrumentos de análise como entrevistas e observação natural, os protótipos foram testados, obtendo respostas esclarecedoras relativamente ao objetivos dos protótipos. Foi observado que a RA é vista pelos médicos como uma solução com potencial, com as soluções apresentadas ao nível de inputs, interface e registo a serem bem recebidas. A projeção bidimensional oferecida pela imagem ultra-som foi encarada como insuficientes, sendo sugerida a sua substituição por um aumento tridimensional capaz de facilitar a correta inserção da agulha.

Influence of laparoscopy and laparotomy on gasometry, leukocytes and cytokines in a rat abdominal sepsis model

Laparoscopic surgery is associated with reduced surgical trauma, and less acute phase response, as compared with open surgery. Cytokines are important regulators of the biological response to surgical and anesthetic stress. The aim of this study was to determine if CO2 pneumoperitoneum would change cytokine expression, gas parameters and leukocyte count in septic rats. Methods: Wistar rats were randomly assigned to five groups: control (anesthesia only), laparotomy, CO2 pneumoperitoneum, cecum ligation and puncture by laparotomy, and laparoscopic cecum ligation and puncture. After 30 min of the procedures, arterial blood samples were obtained to determine leukocytes subpopulations by hemocytometer. TNFα, IL-1β, IL-6 were determined in intraperitoneal fluid (by ELISA). Gas parameters were measured on arterial blood, intraperitoneal and subperitoneal exsudates. Results: Peritoneal TNFα, IL-1β and IL-6 concentrations were lower in pneumoperitoneum rats than in all other groups (p<0.05). TNFα, IL-1β and IL-6 expression was lower in the laparoscopic than in laparotomic sepsis (p<0.05). Rats from laparoscopic cecum ligation and puncture group developed significant hypercarbic acidosis in blood and subperitoneal fluid when compared to open procedure group. Total white blood cells and lymphocytes were significantly lower in laparoscopic cecum ligation and puncture rats than in the laparotomic (p<0.01). Nevertheless, the laparotomic cecum ligation rats had a significant increase in blood neutrophils and eosinophils when compared with controls (p<0.05). Conclusions: This study demonstrates that the CO2 pneumoperitoneum reduced the inflammatory response in an animal model of peritonitis with respect to intraperitoneal cytokines, white blood cell count and clinical correlates of sepsis. The pneumoperitoneum produced hypercarbic acidosis in septic animals

Gallbladder Perforation with Postoperative Preservation of Peritoneal Dialysis Catheter

A patient undergoing peritoneal dialysis was admitted with acute peritoneal dialysis-related peritonitis. On the 10th day of intraperitoneal antibacterial therapy, the patient’s dialysate developed a green color. Gallbladder perforation was revealed. The patient underwent a conventional cholecystectomy with a preserved peritoneal catheter. There are few cases in the medical literature about green dialysate. In all of them, peritoneal dialysis catheters were removed after cholecystectomy. The present case report shows a patient with an intact peritoneal catheter and with no further complications.

Miotomía extendida en el tratamiento de la acalasia

La acalasia es una enfermedad esofágica poco frecuente que se acompaña de una importante alteración de la calidad de vida de los pacientes. Su etiología no está totalmente aclarada y sus características clínicas principales son la disfagia y la regurgitación. El tratamiento de la acalasia está dirigido al alivio funcional y sintomático mediante la abertura del esfínter esofágico inferior, siendo al momento la miotomía laparoscópica la técnica de elección mientras que las dilataciones neumáticas y la inyección de toxina botulínica deben considerarse como técnicas de recurso en casos seleccionados. Objetivo: Evaluar los resultados de la miotomía extendida más funduplicatura parcial anterior de Dorr como tratamiento de la acalasia por vía laparoscópica, comparándola con nuestra experiencia previa mediante la técnica estándar. Materiales y método: diseño: Estudio prospectivo, descriptivo y longitudinal. Sede: Hospital Latino, Cuenca - Ecuador. Pacientes y método: Desde junio de 1992 hasta diciembre del 2011 se intervinieron 39 pacientes con diagnóstico de acalasia que recibieron tratamiento quirúrgico por medio de cirugía mínimamente invasiva. Se estudió la edad, sintomatología previa, clasificación según Stewart, tiempo de evolución de los síntomas, técnica operatoria realizada, control postoperatorio. Resultados: Se intervinieron 39 paciente, con edad promedio de 66 años, mínima 23 y máxima 81. La sintomatología presentada fue disfagia en el 100%, regurgitación en el 74,4%, pérdida de peso en el 71,8% y odinofagia en el 28.2%. El tiempo de evolución de los síntomas fueron: menor a 2 años 48.7% (n=19), de 2 a 4 años 33.3% (n=13), de 4 a 6 años de 12.8% (n=5), y de 6 a 8 años un 5.1% (n=2). Según Stewart se clasificaron en I 8% (n=3), II 49% (n=19), III 38% (n=15) y IV 5% (n=2).La técnica empleada fue Miotomía + Dorr 57% (n=22), Miotomía extendida + Dorr 20% (n=8), Miotomía sola 18% (n=7), Miotomía + Toupet 5% (n=2). Se ha realizado seguimiento del 75% de pacientes, con resultados excelentes en el 91%, y bueno en el 9%. En los ocho últimos casos se realizó la miotomía extendida más funduplicatura tipo Dorr, brindando resultados excelentes a corto plazo. Conclusión: la miotomía gástrica extendida mejora el resultado de la terapia quirúrgica para la acalasia sin incrementar la tasa de reflujo gastroesofágico anormal cuando se añade una funduplicatura parcial anterior tipo Dorr.