Barrett`s esophagus (BE) and carcinoma in the esophageal stump (ES) after esophagectomy with gastric pull-up in achalasia patients: A study based on 10 years follow-up

Background: Subtotal esophagectomy and gastric pull-up with cervical anastomosis is the main treatment for advanced achalasia. This surgical technique has been associated to esophagitis and also Barrett`s epithelium following esophagectomy. Aim: To analyze late clinical, endoscopic, and pathologic findings in the esophageal stump (ES) mucosa after subtotal esophagectomy in patients treated for advanced chagasic achalasia. Methods: 101 patients submitted to esophagectomy and cervical gastroplasty were followed-up prospectively for a mean of 10.5 +/- 8.8 years. All patients underwent clinical, endoscopic and histopathological evaluation every 2 years. Gastric acid secretion was also assessed. Results: The incidence of esophagitis in the esophageal stump (45.9% at 1 year; 71.9% at 5 years, and 70.0% at 10 years follow-up); gastritis in the transposed stomach (20.4% at 1 year, 31.0% at 5 years, and 40.0% at 10 or more years follow-up), and the occurrence of ectopic columnar metaplasia and Barrett`s Esophagus in the ES (none until 1 year; 10.9% between 1 and 5 years; 29.5% between 5 and 10 years; and 57.5% at 10 or more years follow-up), all rose over time. Gastric acid secretion returns to its preoperative values 4 years postoperatively. Esophageal stump cancer was detected in the setting of chronic esophagitis in five patients: three squamous cell carcinomas and two adenocarcinomas. Conclusion: (1) Esophagitis and Barrett`s esophagus in the esophageal stump rose over time. (2) These mucosal alterations and the development of squamous cell carcinoma and adenocarcinoma are probably due to exposure to duodenogastric reflux, and progressively higher acid output in the transposed stomach.

Biliary tract reconstruction using jejunal tube: an experimental study in dogs

BACKGROUND: To physiologically reconstruct the biliary tract, Crema et al suggested the application of the Monti principle to the biliary tract, already used in humans for the urinary tract. With this technique, a jejunal segment is transversely retubularized. This study aimed to evaluate the efficacy of jejunal tube interposition between the common bile duct and duodenum in dogs.METHODS: Thirteen dogs underwent a laparoscopic common bile duct ligature, followed by a biliodigestive connection by jejunal tube interposition after one week. The levels of glutamic-pyruvic and glutamic-oxalacetic transaminases, total bilirubins, alkaline phosphatase and gamma-glutamyltransferase were assessed before surgery and thereafter weekly until euthanasia, which was performed 6 weeks after biliodigestive connection.RESULTS: Data on 9 dogs were analyzed statistically. The dogs presented with obstructive jaundice after common bile duct ligature, as confirmed by biochemical examination. They showed a statistically significant reduction in cholestasis after biliodigestive connection by jejunal tube interposition and were healthy until the end of the experiment.CONCLUSION: A statistically significant reduction was seen in total bilirubin and canalicular enzymes (alkaline phosphatase and gamma-glutamyltransferase) in the 9 dogs 6 weeks after biliodigestive conviction by jejunal tube interposition.

Iterative Reconstruction Algorithm for Abdominal Multidetector CT at Different Tube Voltages: Assessment of Diagnostic Accuracy, Image Quality, and Radiation Dose in a Phantom Study

To assess the diagnostic accuracy, image quality, and radiation dose of an iterative reconstruction algorithm compared with a filtered back projection (FBP) algorithm for abdominal computed tomography (CT) at different tube voltages.

Low-tube-voltage, high-tube-current multidetector abdominal CT: improved image quality and decreased radiation dose with adaptive statistical iterative reconstruction algorithm--initial clinical experience

To investigate whether an adaptive statistical iterative reconstruction (ASIR) algorithm improves the image quality at low-tube-voltage (80-kVp), high-tube-current (675-mA) multidetector abdominal computed tomography (CT) during the late hepatic arterial phase.

Simultaneous two-wavelength holographic interferometry in a superorbital expansion tube facility

A new variation of holographic interferometry has been utilized to perform simultaneous two-wavelength measurements, allowing quantitative analysis of the heavy particle and electron densities in a superorbital facility. An air test gas accelerated to 12 km/s was passed over a cylindrical model, simulating reentry conditions encountered by a space vehicle on a superorbital mission. Laser beams with two different wavelengths have been overlapped, passed through the test section, and simultaneously recorded on a single holographic plate. Reconstruction of the hologram generated two separate interferograms at different. angles from which the quantitative measurements were made. With this technique, a peak electron concentration of (5.5 +/- 0.5) x 10(23) m(-3) was found behind a bow shock on a cylinder. (C) 1997 Optical Society of America.

Total gastric transposition is better than partial gastric tube esophagoplasty for esophageal replacement in children

Whenever the surgeon uses the stomach as an esophageal substitute, either one of two techniques is generally performed: total gastric transposition or gastric tube esophagoplasty. No existing reports compare the complications associated with these two surgical procedures. The purpose of this study is to review the authors` experience with total gastric transposition and verify whether this technique is superior to gastric tube esophagoplasty in children by comparing the main complications with those reported in the publications of gastric tubes esophagoplasties in the English language literature published in the last 38 years. A total of 35 children underwent total gastric transposition according to the classical technique. Most of these patients (27, or 77.1%) had long gap esophageal atresia. The most frequently observed complications were compared to those reported in nine studies of gastric tube esophagoplasty comprising 184 patients. Mortality and graft failure rates were also compared. Seven patients (20.0%) presented with leaks, all of which closed spontaneously. Six children were reoperated, three experienced gastric outlet obstruction secondary to axial torsion of the stomach placed in the retrosternal space and the other three experienced delayed gastric emptying that required revision of the piloroplasty. There were two deaths (5.7%) and no graft failure. Strictures were observed in five patients (14.2%) and all of these were resolved with endoscopic dilatations. Six patients had diarrhea that spontaneously resolved. In the late follow-up period, all patients were on full feed and thriving well. The comparisons with gastric tube patients demonstrated that the total gastric transposition group presented with significantly less leaks and strictures (P = 0.0001 and 0.001, respectively). The incidence of death and graft failure was not statistically different. In conclusion, gastric transposition is as a simple technical procedure for esophageal replacement in children with satisfactory results, and is superior to gastric tube esophagoplasty.

Laryngotracheal reconstruction for pediatric glotto-subglottic stenosis.

BACKGROUND: The management of pediatric laryngotracheal stenosis (LTS) can be challenging, and laryngotracheal reconstruction (LTR) with cartilage interposition grafting remains the mainstay of surgical treatment for pediatric LTS in most experienced centers. The purpose of this study was to report the results of this procedure in a center where primary cricotracheal resection is frequently performed. METHODS: A retrospective chart review was performed on 45 patients who underwent LTR in our hospital between October 1997 and July 2012. Demographic characteristics and information on the preoperative status, stenosis, and operation were collected. Primary outcomes were measured as overall (ODR) and operation-specific (OSDR) decannulation rates and secondary outcomes as morbidity, mortality, and postoperative functional results. RESULTS: ODR and OSDR were 86.7% (39/45) and 66.7% (30/45), respectively. Re-stenosis was observed in 11/45 (24%) patients, all of whom were endoscopically or surgically treated. Revision surgery was performed in 10 patients, 6 for re-stenosis and 2 for peristomial tracheomalacia. Two children died of mucous obstruction of tracheostomy tube at 3 and 6 months postoperatively (4.4%). Respiratory, voice, and swallowing functions were excellent or good in 86, 75, and 84% of patients, respectively. CONCLUSIONS: LTR for pediatric LTS has high decannulation rates with acceptable morbidity and mortality in selected patients. Most LTR procedures were double-stage for lower grade subglottic stenoses associated with glottic involvement that required stenting. Careful preoperative evaluation and adequate surgical indications are extremely important to achieve high decannulation rates.

Endoleak and in-stent thrombus detection with CT angiography in a thoracic aortic aneurysm phantom at different tube energies using filtered back projection and iterative algorithms.

PURPOSE: To determine the lower limit of dose reduction with hybrid and fully iterative reconstruction algorithms in detection of endoleaks and in-stent thrombus of thoracic aorta with computed tomographic (CT) angiography by applying protocols with different tube energies and automated tube current modulation. MATERIALS AND METHODS: The calcification insert of an anthropomorphic cardiac phantom was replaced with an aortic aneurysm model containing a stent, simulated endoleaks, and an intraluminal thrombus. CT was performed at tube energies of 120, 100, and 80 kVp with incrementally increasing noise indexes (NIs) of 16, 25, 34, 43, 52, 61, and 70 and a 2.5-mm section thickness. NI directly controls radiation exposure; a higher NI allows for greater image noise and decreases radiation. Images were reconstructed with filtered back projection (FBP) and hybrid and fully iterative algorithms. Five radiologists independently analyzed lesion conspicuity to assess sensitivity and specificity. Mean attenuation (in Hounsfield units) and standard deviation were measured in the aorta to calculate signal-to-noise ratio (SNR). Attenuation and SNR of different protocols and algorithms were analyzed with analysis of variance or Welch test depending on data distribution. RESULTS: Both sensitivity and specificity were 100% for simulated lesions on images with 2.5-mm section thickness and an NI of 25 (3.45 mGy), 34 (1.83 mGy), or 43 (1.16 mGy) at 120 kVp; an NI of 34 (1.98 mGy), 43 (1.23 mGy), or 61 (0.61 mGy) at 100 kVp; and an NI of 43 (1.46 mGy) or 70 (0.54 mGy) at 80 kVp. SNR values showed similar results. With the fully iterative algorithm, mean attenuation of the aorta decreased significantly in reduced-dose protocols in comparison with control protocols at 100 kVp (311 HU at 16 NI vs 290 HU at 70 NI, P ≤ .0011) and 80 kVp (400 HU at 16 NI vs 369 HU at 70 NI, P ≤ .0007). CONCLUSION: Endoleaks and in-stent thrombus of thoracic aorta were detectable to 1.46 mGy (80 kVp) with FBP, 1.23 mGy (100 kVp) with the hybrid algorithm, and 0.54 mGy (80 kVp) with the fully iterative algorithm.

Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction.

OBJECTIVE: To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). MATERIALS AND METHODS: Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. RESULTS: For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. CONCLUSION: LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %.

Laparoscopic Pancreatic Enucleation With End-to-End Pancreatic Duct Reconstruction.

BACKGROUND: Laparoscopic enucleation for neuroendocrine pancreatic tumors has become a feasible technique, with a reported incidence of pancreatic fistula ranging from 13 to 29 %.1 (-) 3 This report describes the first successful case of laparoscopic pancreatic enucleation with resection of the main pancreatic duct followed by end-to-end anastomosis. METHODS: A 41-year-old woman was admitted to the authors' hospital for repeated syncope. Hypoglycemia also was noted. A contrast-enhanced computed tomography examination showed a highly enhanced tumor measuring 22 mm in diameter on the ventral side of the pancreatic body adjacent to the main pancreatic duct. The patient's blood insulin level was elevated, and her diagnosis was determined to be pancreatic insulinoma. Laparoscopic pancreatic enucleation was performed. Approximately 2 cm of the main pancreatic duct was segmentally resected, and a short stent (Silicone tube: Silastic, Dow Corning Corporation, Midland, MI) was inserted. The direct anastomosis of the main pancreatic duct was performed using four separate sutures with an absorbable monofilament (6-0 PDS). RESULTS: The operation time was 166 min, and the estimated blood loss was 100 mL. The postoperative course was uneventful, and the patient was discharged from hospital on postoperative day 7. The pathologic findings showed a well-differentiated insulinoma and a negative surgical margin. A computed tomography examination performed 1 month after the operation showed a successful anastomosis with a patent main pancreatic duct. CONCLUSIONS: Laparoscopic segmental resection of the main pancreatic duct and end-to-end anastomosis can be performed safely with the insertion of a short stent. This technique also can be used for a central pancreatectomy.

Proposal of a new technique for bile duct reconstruction after iatrogenic injury. Study in dogs and review of the literature

Purpose: Interposition of a jejunal tube between the common bile duct and duodenum. Methods: Five adult mongrel dogs of both sexes, weighing on average 22.3 kg (18 to 26.5 kg), were used. Obstructive jaundice was induced by ligation of the distal common bile duct. After one week, a 2.5-cm long jejunal tube was fabricated from a segment of the loop removed 15 cm from the Treitz angle and interposed between the common bile duct and duodenum. Results: The animals presented good clinical evolution and no complications were observed. After 6 weeks, complete integration was noted between the bile duct mucosa, tube and duodenum and a significant reduction in total bilirubin and alkaline phosphatase was observed when compared to the values obtained one week after ligation of the common bile duct. Conclusion: The jejunal tube interposed between the dilated bile duct and duodenum showed good anatomic integration and reduced total bilirubin and alkaline phosphatase levels in the animals studied.

Performance of the CMS drift tube chambers with cosmic rays

Studies of the performance of the CMS drift tube barrel muon system are described, with results based on data collected during the CMS Cosmic Run at Four Tesla. For most of these data, the solenoidal magnet was operated with a central field of 3.8 T. The analysis of data from 246 out of a total of 250 chambers indicates a very good muon reconstruction capability, with a coordinate resolution for a single hit of about 260 μm, and a nearly 100% efficiency for the drift tube cells. The resolution of the track direction measured in the bending plane is about 1.8 mrad, and the efficiency to reconstruct a segment in a single chamber is higher than 99%. The CMS simulation of cosmic rays reproduces well the performance of the barrel muon detector. © 2010 IOP Publishing Ltd and SISSA.

Human Fallopian Tube Mesenchymal Stromal Cells Enhance Bone Regeneration in a Xenotransplanted Model

We have recently reported that human fallopian tubes, which are discarded during surgical procedures of women submitted to sterilization or hysterectomies, are a rich source of human fallopian tube mesenchymal stromal cells (htMSCs). It has been previously shown that human mesenchymal stromal cells may be useful in enhancing the speed of bone regeneration. This prompted us to investigate whether htMSCs might be useful for the treatment of osteoporosis or other bone diseases, since they present a pronounced capacity for osteogenic differentiation in vitro. Based on this prior knowledge, our aim was to evaluate, in vivo, the osteogenic capacity of htMSCs to regenerate bone through an already described xenotransplantation model: nonimmunosuppressed (NIS) rats with cranial defects. htMSCs were obtained from five 30-50 years old healthy women and characterized by flow cytometry and for their multipotenciality in vitro capacity (osteogenic, chondrogenic and adipogenic differentiations). Two symmetric full-thickness cranial defects on each parietal region of seven NIS rats were performed. The left side (LS) of six animals was covered with CellCeram (Scaffdex)-a bioabsorbable ceramic composite scaffold that contains 60% hydroxyapatite and 40% beta-tricalciumphosphate-only, and the right side (RS) with the CellCeram and htMSCs (10(6) cells/scaffold). The animals were euthanized at 30, 60 and 90 days postoperatively and cranial tissue samples were taken for histological analysis. After 90 days we observed neobone formation in both sides. However, in animals euthanized 30 and 60 days after the procedure, a mature bone was observed only on the side with htMSCs. PCR and immunofluorescence analysis confirmed the presence of human DNA and thus that human cells were not rejected, which further supports the imunomodulatory property of htMSCs. In conclusion, htMSCs can be used successfully to enhance bone regeneration in vivo, opening a new field for future treatments of osteoporosis and bone reconstruction.

Compressed sensing in digital tomosynthesis reconstruction

In this work we study a model for the breast image reconstruction in Digital Tomosynthesis, that is a non-invasive and non-destructive method for the three-dimensional visualization of the inner structures of an object, in which the data acquisition includes measuring a limited number of low-dose two-dimensional projections of an object by moving a detector and an X-ray tube around the object within a limited angular range. The problem of reconstructing 3D images from the projections provided in the Digital Tomosynthesis is an ill-posed inverse problem, that leads to a minimization problem with an object function that contains a data fitting term and a regularization term. The contribution of this thesis is to use the techniques of the compressed sensing, in particular replacing the standard least squares problem of data fitting with the problem of minimizing the 1-norm of the residuals, and using as regularization term the Total Variation (TV). We tested two different algorithms: a new alternating minimization algorithm (ADM), and a version of the more standard scaled projected gradient algorithm (SGP) that involves the 1-norm. We perform some experiments and analyse the performance of the two methods comparing relative errors, iterations number, times and the qualities of the reconstructed images. In conclusion we noticed that the use of the 1-norm and the Total Variation are valid tools in the formulation of the minimization problem for the image reconstruction resulting from Digital Tomosynthesis and the new algorithm ADM has reached a relative error comparable to a version of the classic algorithm SGP and proved best in speed and in the early appearance of the structures representing the masses.

Functional outcome after total and subtotal glossectomy with free flap reconstruction

BACKGROUND: The aim of this study was to evaluate postoperative oral functions of patients who had undergone total or subtotal (75%) glossectomy with preservation of the larynx for oral squamous cell carcinomas. METHODS: Speech intelligibility and swallowing capacity of 17 patients who had been treated between 1992 and 2002 were scored and classified using standard protocols 6 to 36 months postoperatively. The outcomes were finally rated as good, acceptable, or poor. RESULTS: The 4-year disease-specific survival rate was 64%. Speech intelligibility and swallowing capacity were satisfactory (acceptable or good) in 82.3%. Only 3 patients were still dependent on tube feeding. Good speech perceptibility did not always go together with normal diet tolerance, however. CONCLUSIONS: Our satisfactory results are attributable to the use of large, voluminous soft tissue flaps for reconstruction, and to the instigation of postoperative swallowing and speech therapy on a routine basis and at an early juncture. (c) 2008 Wiley Periodicals, Inc. Head Neck, 2008.