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D Rattner

Publications and source records attributed to D Rattner.

At least 19 recordsLinked to original sources
PubMed2006

Evaluating an optimal gastric closure method for transgastric surgery.

BACKGROUND: The transgastric approach is currently being studied as a potentially less invasive alternative to conventional laparoscopy for intra-abdominal surgery. A major obstacle to overcome is the closure of the transgastric incision in a rapid, reproducible, and safe manner. The effectiveness of various techniques for gastrotomy closure were compared by assessing leak pressures in an ex vivo porcine stomach model. METHODS: Whole stomachs from adult white pigs were suspended in a Plexiglas box to facilitate endoscopic technique. Standard gastrotomies were made by needle knife incision and dilation with a controlled radial expansion (CRE) balloon. The first arm used standard QuickClips; the second, a prototype device developed by LSI Solutions; the third, hand-sewn by a senior surgeon; the final, a control with open gastrotomy. Five stomachs were tested per study arm. After closure, each stomach was inflated by an automated pressure gauge. The pressures to achieve air leakage and liquid leakage were recorded. RESULTS: The unclosed controls demonstrated air leakage at a median pressure of 15 mmHg, representing baseline system resistance. The QuickClip closures leaked air at a median pressure of 33 mmHg. The prototype gastrotomy device yielded the highest median air leak pressure of 85 mmHg while dramatically diminishing time for incision and gastrotomy closure to approximately 5 min. The hand-sewn closures leaked air at a median pressure of 47 mmHg. Using Kruskal-Wallis statistical analysis, the comparisons were significant (p = 0.0019). Post hoc paired comparisons using MULTTEST procedure with both Bonferroni and bootstrap adjustments revealed that the difference between prototype and clips was significant; prototype versus hand-sewn was not. Liquid-leak pressures produced similar results. CONCLUSIONS: The prototype device decreases procedure time and yields leak-resistant gastrotomy closures that are superior to clips and rival hand-sewn interrupted stitches.

Animals↗
PubMed2004

Does multidetector-row CT eliminate the role of diagnostic laparoscopy in assessing the resectability of pancreatic head adenocarcinoma?

BACKGROUND: We hypothesized that the high-quality images from multidetector-row computed tomography (MDCT) would lead to improved sensitivity and specificity for predicting resectable pancreatic head adenocarcinoma, thus diminishing the value of staging laparoscopy. METHODS: Forty four consecutive patients underwent thin-section dual-phase MDCT to stage their tumor, followed by an attempted pancreaticoduodenectomy. Four radiologists who were blinded to the operative outcome reviewed the scans and graded the presence of distant and nodal metastases, as well as the degree of arterial and portal involvement. The radiologic criteria for resectability were no distant metastasis, a patent portal vein, and < 50% arterial involvement. RESULTS: The overall resectability for this cohort was 52% (23/44). The 21 unresectable cases, included five liver metastases, three peritoneal metastases, and 13 locally invasive tumors. The negative margin resection rate was 34% (15/44). There were no portal vein resections. The sensitivity and specificity of MDCT for predicting resectability were 96% (22/23) and 33% (7/21), respectively. In this cohort, the positive and negative predictive values were 61% (22/36) and 87.5% (7/8), respectively. As determined by univariate logistic regression, only the degree of arterial involvement was a significant predictor of resectability (p = 0.02). As determined by multivariate logistic regression using both arterial and portal involvement, arterial involvement was predictive (p = 0.03) but portal vein involvement was not (p = 0.45). CONCLUSIONS: Despite the improvements in image quality obtained with multidetector-row technology, CT imaging remains a relatively nonspecific test for predicting resectability in patients with adenocarcinoma of the head of the pancreas. Minimally invasive modalities with higher specificity, particularly laparoscopy, continue to have an important role in staging pancreatic head adenocarcinoma.

Adenocarcinoma↗
PubMed2002

Multimodal simulation of laparoscopic Heller myotomy using a meshless technique.

In this work we focus our attention on developing a surgical simulator for performing laparoscopic Heller myotomy using force feedback. A meshless numerical technique, the method of finite spheres, is used for the purpose of physically based, real time haptic and graphical rendering of soft tissues. Localized discretization allows display of deformations in the vicinity of the tool tip as well as interaction forces at high update rates (kHz). Novel cutting algorithms are implemented using point-based representation of anatomical models. Graphical rendering is accomplished by using a recently developed volumetric rendering technique known as splatting.

Computer Graphics↗
PubMed1998

Subcellular kinetics of early trypsinogen activation in acute rodent pancreatitis.

To investigate the debated role of intracellular trypsinogen activation and its relation to lysosomal enzyme redistribution in the pathogenesis of acute pancreatitis, rats were infused with the cholecystokinin analog caerulein at 5 micrograms.kg-1.h-1 for intervals up to 3 h, and the changes were contrasted with those in animals receiving saline or 0.25 microgram.kg-1.h-1 caerulein. Saline or 0.25 microgram.kg-1.h-1 caerulein did not induce significant changes. In contrast, 5 micrograms.kg-1.h-1 caerulein caused significant hyperamylasemia and pancreatic edema within 30 min. Pancreatic content of trypsinogen activation peptide (TAP) increased continuously (significant within 15 min). TAP generation was predominantly located in the zymogen fraction during the first hour but expanded to other intracellular compartments thereafter. Cathepsin B activity in the zymogen compartment increased continuously throughout the experiments and correlated significantly with TAP generation in the same compartment. Total trypsinogen content increased to 143% with marked interstitial trypsinogen accumulation after 3 h. Supramaximal caerulein stimulation causes trypsinogen activation by 15 min that originates in the zymogen compartment and is associated with increasing cathepsin B activity in this subcellular compartment. However, a much larger pool of trypsinogen survives and accumulates in the extracellular space and may become critical in the evolution of necrotizing pancreatitis.

Acute Disease↗
PubMed1996

Early results of laparoscopic surgery for colorectal cancer. Retrospective analysis of 372 patients treated by Clinical Outcomes of Surgical Therapy (COST) Study Group.

UNLABELLED: This study was undertaken to determine the early experience of the embers of the COST Study Group with colorectal cancer treated by laparoscopic approaches. METHOD: A retrospective review was performed of all patients with colorectal cancer treated with laparoscopy by the COST Study Group before August 1994. Tumor site, stage, differentiation, procedure completion, presence of recurrence (local, distant, trocar site), and cause of death were analyzed. RESULTS: A total of 372 patients with adenocarcinoma of the colon and rectum were treated by laparoscopic approach between October 1991 and August 1994 (170 men and 192 women): right colectomy, 170; sigmoid colectomy, 55; low anterior resection, 56; abdominoperineal resection, 44; left colectomy, 22; colostomy, 8; total colectomy, 6; transverse colectomy, 7; exploration, 2. Conversion to an open procedure was required in 15.6 percent of cases. Operative mortality was 2 percent. Tumor characteristics were as follows: TNM state: I, 40 percent; II, 25 percent; III, 18 percent; IV, 17 percent; Differentiation: well-moderate, 88 percent; poor, 12 percent; carcinomatosis, 5 percent. Local (3.6 percent) and distant implantation occurred in four patients (1.1 percent). Only one of these patients died a cancer-related death (Stage III at 36 months). Cancer-related death rates increased with increasing stage of tumor: I, -4 percent; II, 17 percent; III, 31 percent; IV, 70 percent. CONCLUSION: A laparoscopic approach to colorectal cancer results in early outcome after treatment that is comparable with conventional therapy for colorectal cancer. A randomized trial is needed to compare long-term outcomes of open and laparoscopic approaches with colorectal cancer.

Adenocarcinoma↗
PubMed1996

[On the hypothesis of cesarean birth rate stabilization in southeastern, Brazil].

Births in S. Paulo State (Brazil) between 1987 and 1993 were studied to test the association between cesarean section rates and the social and economic development. The study used both Health Regions and hospitals as units of analysis. The cross-sectional study of secondary data adopted as variables: cesarean section rates in 1987, 1992 and 1993 by hospital and region; kind of provider; link of hospital with medical school; post-neonatal infant mortality rate; number of banks per inhabitant; and consumption potential of the regional central town per inhabitant. The C-section rates in the period studied were around 48% for the State; between 21.3 and 85.5% for the regions; between zero and 100% for the hospitals; as for kind of provider, the higher rates were found in private hospitals (56% in 1993). Medical school hospitals held stable rates throughout the period, around 39%. The multiple linear regression showed that banks per inhabitant and consumption potential by inhabitants explained 48% of the variation of the regional C-section rates. The stabilization of the State C-section rates is questioned, since the data shows a shift in the mode of hospital rates to higher values. A re-structure of the care delivered to births is imperative in S. Paulo State, since cesarean sections, besides being medical procedures, have become a consumer good, a symptom of the perverse logic that pervades the current organization of the health system.

Analysis of Variance↗
PubMed1996

[Epidemiological standards for assessing quality: a proposal]

This paper proposes a strategy for defining indicators to assess the quality of the process of health care, based on the identification of the objectives of the care being delivered and on the verification of whether the technical guidelines for the procedures are being enforced. The article goes on to apply the proposed methodology to the process of health care during childbirth, based on a perspective of comprehensive care and adopting both an individual and collective risk approach. It uses a data bank of 4,558 Simplified Perinatal Clinical Histories (CLAP/PAHO/WHO) from 12 hospitals.The indicators selected were: V.D.R.L., Rh blood typing, antitetanus vaccination, rate of cesarean sections, reception of the baby by a pediatrician at birth, Apgar score, evaluation of the gestational age by physical exam, rooming-in, exclusive breastfeeding upon discharge, and referral for a puerperal consultation. Methods for classification of hospitals were the sum of their scores for each indicator, gold standard, and ranking. This methodology warranted identification of one hospital with excellent quality of care, five with good care, two with fair care, and four whose performances were completely unsatisfactory. Finally, some remarks on the assessment of quality of health care are made and future developments are proposed.

Journal Article↗
PubMed1991

Treatment of critically ill patients with sepsis of unknown cause: value of percutaneous cholecystostomy.

Because of the difficulty in diagnosing acute cholecystitis in critically ill patients with severe intercurrent illness by clinical and imaging methods or percutaneous aspiration of the gallbladder, a trial of percutaneous cholecystostomy was performed in 24 patients in the intensive-care unit with persistent, unexplained sepsis after a complete clinical, laboratory, and radiologic search showed no alternative source of infection. Persistent high fevers, despite antibiotic therapy, were present in all patients, with elevated WBC count in 18 patients, vague abdominal tenderness in 11, and septic shock requiring vasopressors in 15. Sonographically, all patients had distended, spherical gallbladders, six had gallstones, eight had wall thickening, three had pericholecystic fluid, and four had Murphy's sign. All patients were seen by a senior abdominal surgeon, who agreed to a trial of percutaneous cholecystostomy. Fourteen patients (58%) responded to percutaneous cholecystostomy, as evidenced by a decrease in WBC count, defervescence, and the ability to be weaned off vasopressors. Bile cultures were positive in four patients. Ten patients (42%) did not respond to percutaneous cholecystostomy; five eventually died of unrelated causes. A respiratory source of infection was eventually found in three of these 10 patients, with no proved source of infection in the remainder. No complications related to catheter insertion occurred in this group of patients. Bile leaks occurred in two patients when the percutaneous cholecystostomy catheter was removed, but without serious consequence. Our experience suggests that a lower threshold for performing percutaneous cholecystostomy in this difficult clinical subset of patients is worthwhile.

Acute Disease↗
PubMed1985

Transepithelial transport of guinea pig gastric mucous cell monolayers.

Guinea pig gastric mucous epithelial cells were isolated, enriched, cultured in collagen cups, and put into Ussing chambers for electrophysiological studies. The cultured mucous cell monolayers, which retain the morphology of surface cells found in the intact tissue, had a maximal resistance (R) of 272 +/- 12 omega X cm2 and a potential difference (PD) of -3.8 +/- 0.4 mV (apical negative) between 4 and 10 days later (n = 33). The current-voltage and conductance-concentration relationships of the cultures were both nonlinear (n = 12). In addition, NaCl concentration gradients across the monolayer also gave asymmetrical and nonlinear dilution potentials, with the side of lower chemical potential always becoming electrically negative (n = 10). Calculation of the average Cl(-)-to-Na+ permeability ratio at pH 7.4 was 1.35, indicating a slightly greater conductance of anions over cations. Amiloride (0.1-1.0 microM) had no effect on PD or R when given from the apical or basal side (n = 18), but at higher concentrations (0.1-1.0 mM) there was a decrease in the PD. 4,4'-Diisothiocyanostilbene-2,2'-disulfonic acid at 10(-4) M increased R from the apical side only (n = 14), and acetazolamide at 5 X 10(-4) M reduced the PD to -0.5 mV (n = 8). Only ouabain at 10(-4) M from the serosal side was effective in reducing the monolayer PD to zero. This culture preparation will prove useful for future studies in determining specific functions for this gastric cell type and how those functions relate to barrier function in the stomach.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗