Management of Left Staghorn Calculus With Colorenal Fistula.

Fistula formation between the kidney and the colon is a rare occurrence. Colorenal fistulas have been reported after renal cryoablation, calculous pyonephrosis, and renal cell carcinoma. Fistula formation is reported in as many as 35% of patients with Crohn's disease. Crohn's-related urinary fistulas may include enterovesical, enteroureteral, rectourethral, urethrocutaneous, and entero-urachal fistulas. Here, we report a rare case of a patient who was found to have a left colorenal fistula in the setting of a left staghorn calculus and recurrent urinary tract infections with a question about the eventual definitive management of the patient.

Tactile devices to sense touch on a par with a human finger.

Our sense of touch enables us to recognize texture and shape and to grasp objects. The challenge in making an electronic skin which can emulate touch for applications such as a humanoid robot or minimally invasive and remote surgery is both in mimicking the (passive) mechanical properties of the dermis and the characteristics of the sensing mechanism, especially the intrinsic digital nature of neurons. Significant progress has been made towards developing an electronic skin by using a variety of materials and physical concepts, but the challenge of emulating the sense of touch remains. Recently, a nanodevice was developed that has achieved the resolution to decipher touch on a par with the human finger; this resolution is over an order of magnitude improvement on previous devices with a sensing area larger than 1 cm(2). With its robust mechanical properties, this new system represents an important step towards the realization of artificial touch.

Analysis of loss of heterozygosity for tumor-suppressor genes can accurately classify and predict the clinical behavior of mucinous tumors arising from the appendix.

BACKGROUND: Pseudomyxoma peritonei is a rare heterogenous clinical syndrome with a variable clinical course. On the basis of the hypothesis that cumulative mutational damage can predict biological aggressiveness, we evaluated the utility of integrated histopathology and molecular analysis for patients with pseudomyxoma peritonei syndrome. METHODS: Tissue specimens from 23 mucinous appendiceal tumors were analyzed. DNA samples from multiple sites were analyzed for loss of heterozygosity by using a panel of 15 allelic loss microsatellite markers and K-ras-2 point mutational damage. The fractional mutational rate (FMR), determined as the number of mutated markers divided by the total number of informative markers, was calculated by using the six most informative markers and the K-ras-2 gene. Kappa statistics were calculated to test the association between FMR and the histopathologic classification. RESULTS: Our study included 6 female and 17 male patients with a mean age of 53.6 years and a mean survival of 43.9 months. We found an association between tumor loss of heterozygosity markers and histopathologic classification (P < .05). In addition, there was also an association between the FMR and pathological classification as well as between the FMR and survival (P < .05). An FMR less than .25 indicated low-grade disease, an FMR of .25 to .50 indicated intermediate grade, and an FMR greater than .5 indicated a high-grade tumor. CONCLUSIONS: Mutational profiling of accumulated allelic loss and point mutational damage correlated strongly with histopathologic definitions of pseudomyxoma peritonei disease and helped to predict the prognosis of these patients. FMR, along with histopathology, offers a comprehensive classification of these rare tumors.

High-resolution thin-film device to sense texture by touch.

Touch (or tactile) sensors are gaining renewed interest as the level of sophistication in the application of minimum invasive surgery and humanoid robots increases. The spatial resolution of current large-area (greater than 1 cm(2)) tactile sensor lags by more than an order of magnitude compared with the human finger. By using metal and semiconducting nanoparticles, a approximately 100-nm-thick, large-area thin-film device is self-assembled such that the change in current density through the film and the electroluminescent light intensity are linearly proportional to the local stress. A stress image is obtained by pressing a copper grid and a United States 1-cent coin on the device and focusing the resulting electroluminescent light directly on the charge-coupled device. Both the lateral and height resolution of texture are comparable to the human finger at similar stress levels of approximately 10 kilopascals.

Current management of locally advanced pancreatic cancer.

Almost 30% of patients with pancreatic cancer present with large, locally advanced tumors in the absence of distant metastases. Because surgical resection is frequently contraindicated by vascular invasion, locally advanced pancreatic cancer has a dismal prognosis with a 6-10-month median survival. Recent advances in the multimodality treatment of other gastrointestinal malignancies have not altered the management of patients with locally advanced pancreatic cancer, a clinical dilemma reflected by the number of nonrandomized trials and anecdotal reports addressing this difficult disease. Our review summarizes the current status of aggressive surgical resection and neoadjuvant chemoradiation for locally advanced pancreatic cancer and suggests a treatment algorithm for patients with this disease based upon published clinical evidence.

Hepatic resection in 170 patients using saline-cooled radiofrequency coagulation.

BACKGROUND: Hepatic resection for malignancies or symptomatic benign liver lesions remains the standard of treatment. Historically, the principal cause of mortality during liver resection was intraoperative bleeding. Advances in surgical and anesthetic techniques, along with application of new technologies, have decreased blood loss and dramatically improved the outcomes for major liver surgery. METHODS: The purpose of this prospective study was to determine the utility of a saline-cooled radiofrequency coagulation device (TissueLink Medical, Inc.) for hepatic resection. Intraoperative bleeding, blood transfusion, postoperative bile leak, and other complications were noted. RESULTS: The results are described for 170 patients undergoing hepatic resection over a three-year period. There were no intraoperative or postoperative deaths. Six patients in the series received blood transfusions for a transfusion rate of 3.5%. Four patients experienced a transient postoperative bile leak. Three of the four closed spontaneously prior to discharge home, and the fourth closed promptly after ERCP. There were no episodes of postoperative hemorrhage, hepatic failure, liver abscess, or reoperation. CONCLUSIONS: The saline-cooled radiofrequency coagulation device is very effective in achieving intraoperative hemostasis and facilitates liver parenchymal transection during hepatic resection.