Background. The benefits of preoperative chemotherapy and radiation for esophageal carcinoma are under investigation. A pilot study was undertaken to determine if pathologic assessment of tumor regression correlated with disease free survival. Methods. Ninety‐three resected specimens from patients treated with cis‐dichloro‐diamino cisplatin and irradiation before surgery were examined on semiserial sections. Patients selected for surgery were all Status 1 according to the World Health Organization (WHO) classification. Histologic typing was based on the WHO classification. Tumor regression grade (TRG) was quantitated in five grades: TRG 1 (complete regression) showed absence of residual cancer and fibrosis extending through the different layers of the esophageal wall; TRG 2 was characterized by the presence of rare residual cancer cells scattered through the fibrosis; TRG 3 was characterized by an increase in the number of residual cancer cells, but fibrosis still predominated; TRG 4 showed residual cancer outgrowing fibrosis; and TRG 5 was characterized by absence of regressive changes. Survival curves were estimated according to the Kaplan‐Meier method. A quantification of the relationship between treatment failure and confounding variables (age, tumor location, tumor size, esophageal wall involvement by residual cancer and/or regressive changes, histology, treatment, adequacy of surgery, pathologic lymph node status, and tumor regression grade) was done using Cox's proportional hazards model. Results. Forty‐two percent of specimens were TGR 1–2; 20%, TGR 3; and 33%, TGR 4–5. Univariate analysis found that tumor size, pathologic lymph node status, tumor regression grade, and esophageal wall involvement were highly correlated with disease free survival (P > 0.05). After multivariate analysis, only tumor regression (i.e., TRG 1–3 versus TRG 4–5) remained a significant (P > 0.001) predictor of disease free survival. Conclusions. This study highlights the importance of tumor regression in the survival of patients with esophageal carcinoma treated with preoperative chemoradiotherapy. These findings suggest that tumor regression grade should be considered when evaluating therapeutic results. Cancer 1994; 73:2680–6.

Abstract-Surgical workflow recognition has numerous potential medical applications, such as the automatic indexing of surgical video databases and the optimization of real-time operating room scheduling, among others. As a result, phase recognition has been studied in the context of several kinds of surgeries, such as cataract, neurological, and laparoscopic surgeries. In the literature, two types of features are typically used to perform this task: visual features and tool usage signals. However, the visual features used are mostly handcrafted. Furthermore, the tool usage signals are usually collected via a manual annotation process or by using additional equipment. In this paper, we propose a novel method for phase recognition that uses a convolutional neural network (CNN) to automatically learn features from cholecystectomy videos and that relies uniquely on visual information. In previous studies, it has been shown that the tool usage signals can provide valuable information in performing the phase recognition task. Thus, we present a novel CNN architecture, called EndoNet, that is designed to carry out the phase recognition and tool presence detection tasks in a multi-task manner. To the best of our knowledge, this is the first work proposing to use a CNN for multiple recognition tasks on laparoscopic videos. Extensive experimental comparisons to other methods show that EndoNet yields state-of-the-art results for both tasks.

This study shows that bypassing a short segment of proximal intestine directly ameliorates type 2 diabetes, independently of effects on food intake, body weight, malabsorption, or nutrient delivery to the hindgut. These findings suggest that a proximal intestinal bypass could be considered for diabetes treatment and that potentially undiscovered factors from the proximal bowel might contribute to the pathophysiology of type 2 diabetes.

Results of our study support the hypothesis that the bypass of duodenum and jejunum can directly control type 2 diabetes and not secondarily to weight loss or treatment of obesity. These findings suggest a potential role of the proximal gut in the pathogenesis the disease and put forward the possibility of alternative therapeutic approaches for the management of type 2 diabetes.

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ObjectiveTo show the feasibility of performing surgery across transoceanic distances by using dedicated asynchronous transfer mode (ATM) telecommunication technology. Summary Background DataTechnical limitations and the issue of time delay for transmission of digitized information across existing telecommunication lines had been a source of concern about the feasibility of performing a complete surgical procedure from remote distances. MethodsTo verify the feasibility and safety in humans, the authors attempted remote robot-assisted laparoscopic cholecystectomy on a 68-year-old woman with a history of abdominal pain and cholelithiasis. Surgeons were in New York and the patient in Strasbourg. Connections between the sites were done with a high-speed terrestrial network (ATM service). ResultsThe operation was carried out successfully in 54 minutes without difficulty or complications. Despite a round-trip distance of more than 14,000 km, the mean time lag for transmission during the procedure was 155 ms. The surgeons perceived the procedure as safe and the overall system as perfectly reliable. The postoperative course was uneventful and the patient returned to normal activities within 2 weeks after surgery. ConclusionsRemote robot-assisted surgery appears feasible and safe. Teletransmission of active surgical manipulations has the potential to ensure availability of surgical expertise in remote locations for difficult or rare operations, and to improve surgical training worldwide.Remote surgical operations require both rapid and accurate transmission of information. Factors that influence significantly the rapidity and accuracy of this information are the time required to convert video images and gestures into electronic signals, and the bandwidth and time lag of existing telecommunication lines.1,2 Using current technology, we recently showed the feasibility of performing remote surgical operations in an experimental animal model.3 Results of our experimental tests allowed us to perform, for the first time, remote robot-assisted surgery on a human. Here we present the case and postoperative course and discuss the current limitations and the potential clinical and social impact of remote telesurgery.

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Abstract-This paper presents a predictive control approach to active mechanical filtering of complex, periodic motions of organs induced by respiration or heart beating in robotized surgery. Two different predictive control schemes are proposed for the compensation of respiratory motions or cardiac motions.For respiratory motions, the periodic property of the disturbance has been included into the input-output model of the controlled system so as to have the robotic system learn and anticipate perturbation motions. A new cost function is proposed for the unconstrained generalized predictive controller (GPC) where reference tracking is decoupled from the rejection of predictable periodic motions.Cardiac motions are more complex since they are the combination of two periodic non-harmonic components. An adaptive disturbance predictor is proposed which outputs future predicted disturbance values. These predicted values are used to anticipate the disturbance by using the predictive feature of a regular GPC.Experimental results are presented on a laboratory testbed and in vivo on pigs. They demonstrate the effectiveness of the two proposed methods to compensate complex physiological motion.