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Biomedical subjects

A Eitan

Publications and source records attributed to A Eitan.

At least 19 recordsLinked to original sources
PubMed1998

Laparoscopic approach to hydatid liver cysts. Is it logical? Physical, experimental, and practical aspects.

BACKGROUND: In recent years attempts have been made to treat hydatid liver cysts laparoscopically. The purpose of this study was to evaluate different aspects of this approach and to examine whether a reasonable model could be developed. METHODS: Three different subjects were analyzed. In the first, physical aspects related to transmembrane pressures were analyzed to demonstrate that evacuation of the cyst under pneumoperitoneum does not carry increased risk of spillage, and may even offer an advantage when the proper technique is used. In the second subject, an isolated liver model of a goat was used to study several techniques for evacuating hydatid cysts without spillage. This was tested qualitatively by demonstrating scolices in the fluid medium around the isolated liver after surgical manipulations. In the third subject, the implication of the technique was evaluated in human patients. RESULTS: According to basic physical assumptions, the following conclusions were reached: (1) The increase in intracystic pressure is equal to or less than the increase in intraperitoneal pressure after pneumoperitoneum. (2) Aspiration of parasitic cysts by laparoscopic needle through a large cannula under "vacuum" or by sealing the cannula and adhering it to the liver by cyanoacrylate or fibrin glue was found to be very safe. Simple needle aspiration failed to prevent spillage. (3) A new transparent cannula 18 mm in diameter with a beveled tip was designed that enables good accessibility to liver cysts and safe evacuation even of huge and complex cysts. CONCLUSIONS: The novel technique to manage hydatid liver cysts, described in the study, is feasible, sensible, and safe. The isolated goat liver containing hydatid cysts can be used as a reliable animal model to test new techniques in the future.

Animals↗
PubMed1998

Laparoscopic cholecystectomy for acute cholecystitis performed by residents in surgery: a risk factor for conversion to open laparotomy?

Recent observations point to a seemingly high conversion rate to laparotomy in cases of laparoscopic operations for acute cholecystitis that are performed by surgical residents. The purpose of the study is to evaluate those observations. In a retrospective nonrandomized study, conducted between February 1992 and December 1997, 285 laparoscopic operations for acute cholecystitis were analyzed. Those performed by attending surgeons were compared with those performed by residents assisted by attending surgeons. Of 123 laparoscopic operations performed by laparoscopic surgeons between February 1992 and September 1995, 20.3% were converted to laparotomy, compared with 41.3% of the 29 operations performed by the residents (p < 0.017), with no increase in complication rate. Factors like male sex, duration of upper abdominal pain, and severity of the inflammatory process were not significantly different in both groups. The residents' seniority did not influence the conversion rate. A constant and significant decrease in conversion rate to laparotomy was observed over the course of time, as the study proceeded to December 31, 1997 (p < 0.01). We conclude that the performance of difficult laparoscopic cholecystectomy by residents with the assistance of attending surgeons is feasible, but carries a higher conversion rate to laparotomy for reasons that are not entirely clear. The possibility of a learning curve of the residents is suggested.

Acute Disease↗
PubMed1997

Imaging supramolecular aggregates in bile models and human bile.

Investigation of cholesterol crystallization is essential for the understanding of gallstone formation. Previous work has revealed a variety of aggregates of different sizes and shapes prior to the appearance of "classical" plate-like cholesterol monohydrate crystals both in native biles and model systems. In this article, we review existing data based on various microscopic techniques and present data on microstructural pathways leading to cholesterol crystal formation in two different bile models and in native bile. In continuation of our recent investigation of microstructures in nucleating human bile, we now present data suggesting that polymorphism is not limited to complex native bile, but also appears in two, simplified model systems. These studies employed cryo-transmission electron microscopy (cryo-TEM) and video-enhanced light microscopy, using Nomarski optics (VELM). Only the combined use of these two complementary, non-perturbing direct methods can cover the whole range of microstructures ranging from a few nanometers to several microns. Concentrated isotropic solutions of bile models, composed of cholesterol, lecithin and taurocholate, were diluted to induce cholesterol supersaturation and start an evolution of microstructures, leading to cholesterol crystallization. Initially, small spheroidal micelles were observed by cryo-TEM. Subsequently, uni-, oligo- and multilamellar vesicles, compatible with structures seen at the same time by VELM, appeared in coexistence with micelles. Thereafter, during a dynamic phase of cholesterol crystallization, filaments, tubular and helical microstructures, as well as classical plate-like cholesterol monohydrate crystals were noted by light microscopy. Eventually, large plate-like crystals were observed by VELM, while cryo-TEM revealed only small spheroidal micelles. The crystallization process in native human bile during ex vivo incubation was found to bear close resemblance to the findings in the model systems, further supporting the applicability of these systems to the exploration of microstructural aspects of nucleating human bile.

Bile↗
PubMed1997

Laparoscopic management of lumbar hernia.

We describe (for the first time) a laparoscopic approach to repair an acquired superior triangle lumbar hernia in a morbidly obese woman by using prosthetic mesh. Such a technique provides an excellent anatomic view, thus avoiding injury to structures in proximity to the hernia during repair; eventually the well-known advantages of such approach result.

Female↗
PubMed1997

Experimental study in bile duct-ligated rats of vasopressin and preoperative volume loading to prevent hypotensive crises.

BACKGROUND: Systemic hypotension may result in postoperative renal failure in jaundiced patients. Attenuated responsiveness to catecholamines and hypovolaemia has been reported in jaundiced animals and may be a mechanism contributing to the increased susceptibility of jaundiced patients to haemorrhagic shock. This suggests that an alternative to vasoactive amines to control perioperative hypotension could be desirable. METHODS: This study evaluated the pressor response to vasopressin in normovolaemic 3-day bile duct-ligated rats and in 3-day bile duct-ligated rats after an acute controlled haemorrhage. It also evaluated the response after volume loading with 0.9 per cent saline, 7.5 per cent saline, colloid and mannitol before controlled haemorrhage. In addition, blood volume was measured using radiolabelled albumin. All the data obtained from bile duct-ligated rats were compared with data from sham-operated animals. RESULTS: Attenuated pressor responses to vasopressin were not observed in either normotensive bile duct-ligated rats or in the bile duct-ligated rats subjected to controlled haemorrhage. Volume loading with the four fluids over the dosing range 2.5-7.5 microliters per g body-weight in bile duct-ligated rats reversed the susceptibility to haemorrhagic hypotension. CONCLUSION: Although no reduction in blood volume was demonstrated, bile duct-ligated rats may have a reduced effective blood volume manifesting itself as a latent hypovolaemia and/or tendency to hypotension. Preoperative fluid loading could be beneficial because it corrects hypovolaemia and improves cardiovascular function, as well as improving the cardiovascular response to haemorrhage.

Animals↗
PubMed1996

Laparoscopic management of acute cholecystitis. Prognostic factors for success.

BACKGROUND: Laparoscopic cholecystectomy for acute cholecystitis is considered feasible and safe, but it is associated with a higher rate of conversion to laparotomy than elective cholecystectomy because of technical reasons and anatomical changes related to the inflammatory process. The value of several factors that might influence its successful completion has not been studied completely yet, including the role of residents in operating such cases under attending-surgeon surveillance. METHODS: In a retrospective nonrandomized study, the medical charts of 182 patients that were operated for acute cholecystitis (94 of whom via the laparoscopic approach) were studied. The study was also conducted to study the effect of residents as operators. RESULTS: Male sex, duration of right upper abdominal pain, and the severity of the inflammatory process have all been significantly and independently correlated with increased conversion rate to laparotomy. Operation time was not longer than that of the open approach, and hospital stay and complication rate were lower. Operations performed by residents were associated with twofold conversion rate to laparotomy, without increased complication rate (p < 0.012). CONCLUSIONS: Laparoscopic management of acute cholecystitis is feasible and safe. Considering the factors discussed above, lowering the threshold for conversion is necessary in selected cases to maintain low morbidity rate. Integrating laparoscopic cholecystectomy for acute cholecystitis into surgical residency should be studied.

Acute Disease↗
PubMed1996

Are the morphology of papillary thyroid carcinoma and the tumour's behaviour correlated?

Six cases of papillary thyroid carcinoma showing clinically highly aggressive behaviour by invading the upper airway and digestive tract structures were retrospectively reviewed to evaluate the morphological variants of the tumours. Four of them were found to be pure papillary and one was a mixed-papillary and follicular-variants regarded as non-aggressive. Only one case was found to be tall cell variant-regarded as an aggressive variant of papillary thyroid carcinoma. The findings suggest that the prognosis of papillary thyroid carcinoma cannot be predicted from its morphological variant and attention should be given to other clinical parameters.

Aged↗
PubMed1996

A technique for second-look laparoscopy in the obese patient.

A technique for second-look laparoscopy in an obese patient suffering from acute mesenteric ischemia is described. A device composed of a 10-mm trocar-sleeve and a large Foley catheter was used, which enables its proper fixation through the abdominal wall, without causing any intestinal damage.

Abdominal Muscles↗
PubMed1996

Antiproliferative effect of pentoxifylline on psoriatic and normal epidermis. In vitro and in vivo studies.

Psoriasis is characterized by abnormal cell proliferation, inflammation and increased biosynthesis of various cytokines. The inhibitory effect of pentoxifylline on some cell functions has been reported widely. This property of pentoxifylline prompted an investigation of its possible role in controlling psoriasis. In the in vitro study normal human keratinocytes proliferation was determined and formation of cornified envelopes was assayed following treatment with pentoxifylline. The in vivo experiment consisted of nude mice grafted with psoriatic or normal skin treated with tetradecanyl phorbol 13 acetate. At the end of the treatment period, the grafts were excised and assessed for acanthosis and labelling index. The in vitro study showed that continuous exposure of normal human keratinocyte cultures to pentoxifylline resulted in a significant dose-dependent inhibition of proliferation, and in induction of cornified envelope formation. The in vivo experiments showed a significant reduction of epidermal thickness and of labeling index in psoriatic and tetradecanyl phorbol 13 acetate-treated normal skin, as compared to the initial values.

Adult↗
PubMed1995

Laparoscopic treatment of a perinephric abscess.

A 21-year-old woman was operated laparoscopically for peritonitis due to penetrating perinephric abscess (PNA). Following correct diagnosis and drainage, a definitive treatment was carried out to drain the intrarenal abscess laparoscopically. Although not the preferred approach, when diagnosed during exploratory laparoscopy for peritonitis, PNA can be successfully treated laparoscopically.

Abscess↗
PubMed1995

The use of a large, transparent cannula, with a beveled tip, for safe laparoscopic management of hydatid cysts of liver.

Aspiration of hydatid cysts and instillation of scolicidal fluid as part of the surgical treatment should be done very carefully to prevent any spillage that might cause anaphylaxis and dissemination of the disease. We describe herein a laparoscopic technique for safe aspiration of hydatid cysts of liver by using an assembled large, transparent trocar sleeve with a beveled tip. The method described allows laparoscopic access even to hydatid cysts that are located under the diaphragm.

Anaphylaxis↗
PubMed1994

[Invasive papillary thyroid carcinoma].

Papillary carcinoma, the most common malignant tumor of the thyroid, infrequently invades the upper aerodigestive tract (larynx, pharynx, trachea and esophagus). However, when invasion does occur, it is a source of significant morbidity and excess mortality; the method of treatment is controversial. In our opinion surgery is the primary treatment modality. Local invasion of the aerodigestive tract by this tumor can be successfully treated by total or subtotal thyroidectomy, excising malignant tissue while preserving function of aerodigestive tract structures. Adjuvant therapy using radioiodine or external beam radiotherapy should be considered integral to any treatment plan. We present our experience with 4 patients with invasive thyroid papillary carcinoma to the larynx, trachea and esophagus.

Carcinoma, Papillary↗
PubMed1994

Direct visualization of lipid aggregates in native human bile by light- and cryo-transmission electron-microscopy.

The evolution of microstructures present in human gallbladder and hepatic bile was observed simultaneously by video-enhanced light microscopy (VELM) and transmission electron microscopy of vitrified specimens (cryo-TEM), as a function of time after withdrawal from patients. Fresh centrifuged gallbladder bile samples contained small (6 nm) spherical micelles in coexistence with vesicles (40 nm). Out of the seven bile samples investigated four contained, in addition, two types of elongated aggregates that have not been previously described. Uncentrifuged gallbladder bile also contained a mixture of ribbon- and plate-like crystals seen by VELM, but not by cryo-TEM. In aged (3-6-week-old) gallbladder bile samples VELM also revealed spiral and helical crystal structures. No such crystals were present in hepatic bile samples, although microcrystals, not observable by VELM were seen by cryo-TEM in addition to micelles and vesicles. The similarity of these observations to those observed in bile models lends strong support for the validity of the model systems. Furthermore, the presence of microcrystals in hepatic bile samples, apparently devoid of crystals by light microscopy, indicates that under certain conditions the common criterion of 'nucleation time' (NT), based on light microscopy, does not represent the real time of nucleation. In the human bile samples investigated in this study the dissociation between NT and the time of observation of microcrystals was seen in hepatic but not in gallbladder bile samples. Hence, crystal growth may be rate limiting only in dilute biles.

Bile↗
PubMed1994

Highly invasive papillary thyroid carcinoma.

Papillary carcinoma is the most common malignant tumour of the thyroid gland, accounting for at least two-thirds of newly diagnosed carcinomas. This tumour may be occasionally multicentric in origin. It frequently spreads to regional lymph nodes in the neck and mediastinum, but uncommonly metastasizes outside these regions. Local invasion of this tumour to the upper airway or digestive tract structures is infrequent. However, when that occurs, it is a source of significant morbidity and mortality. In the last two years four patients suffering from invasive papillary carcinoma to the aerodigestive tract were treated in our department. A short case history of one of them is presented and current trends in management of the disease are reviewed.

Carcinoma, Papillary↗
PubMed1991

[Early vs delayed cholecystectomy for acute cholecystitis].

The timing of cholecystectomy in acute cholecystitis is still controversial. A marked change toward early surgery has been noted in the past decade. In a retrospective study of 197 patients we evaluated the results of cholecystectomy in 117 who underwent elective cholecystectomy, and in 80 operated on during the acute phase of cholecystitis. The diagnosis of acute cholecystitis was by isotope scan (HIDA) or ultrasound. There was no case of misdiagnosis. 3 patients died postoperatively: 2 in the early operation group (1 had emergency cholecystectomy) and 1 in the elective group. Postoperative complications were more frequent in the early surgery group (p = 0.06). The highest morbidity was in early cholecystectomy in those older than 60 years who had cardiovascular disease (p less than 0.0002). Hernia in the scar was a unique complication of the early operation. According to most studies reviewed, early operation eliminates the need for emergency operation when conservative treatment fails, without increasing morbidity or mortality. Therefore, early operation during the acute phase of cholecystectomy is advised. For patients older than 60 years who have cardiovascular disease, we recommend delaying surgery until the acute inflammation subsides. The waiting period before surgery should be as short as possible in order to reduce the risk of recurrent cholecystitis and its complications.

Acute Disease↗