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Biomedical subjects

S Rohr

Publications and source records attributed to S Rohr.

At least 55 records · Page 3Linked to original sources
PubMed1997

[The value of peroperative colonic lavage in urgent colonic surgery. Apropos of 54 patients].

UNLABELLED: The effects of on-table colonic irrigation followed by primary large bowel resection and anastomosis for emergency left colonic disease were prospectively studied in 54 patients. PATIENTS AND METHODS: Eighteen patients had a diverticular sigmoiditis complicated by localized (8) or generalized (4) peritonitis, 6 presented a complete sigmoid obstruction. Thirty six patients had a left colonic occlusive (33) or perforated (3) cancer. Anterograde colonic irrigation was carried out with a mean volume of 7.7 l. All patients received a double or triple antibiotic combination. The anastomosis was handsewn in 33 cases and stapled (Knight-Griffen) in 21. Seven patients with severe peritonitis had a proximal transitory stoma which was closed within 4 months. RESULTS: Two patients (3.7%) died postoperatively, one for anastomotic dehiscence and the second for evisceration. We observed 7 cases of hypothermia (< 34 degrees C) during the irrigation. Six patients developed a sepsis of the surgical wound, 2 a septicemia and l an abscess in the right iliac fossa which was percutaneously drained. All complications had a favourable outcome. CONCLUSION: This study confirms that in selected cases a single stage surgery for colonic emergencies preceded by on-table irrigation grants good results and is a safe and effective alternative to Hartmann's procedure.

Aged↗
PubMed1996

Spatial changes in transmembrane potential during extracellular electrical shocks in cultured monolayers of neonatal rat ventricular myocytes.

This study investigated the role of different types of discontinuities in tissue architecture on the spatial distribution of the transmembrane potential. Specifically, we tested the occurrence of so-called "secondary sources," ie, localized hyperpolarizations and depolarizations during the application of extracellular electrical shocks (EESs). Changes in transmembrane potential relative to action potential amplitude (delta Vm/APA) were measured in patterned cultures of neonatal rat myocytes, stained with voltage-sensitive dye (RH-237), by optical mapping (96-channel photodiode array, 6- to 30-micron resolution) during the application of EES (field strength, 8 to 22 V/cm; duration, 6 ms). Across narrow cell strands (width, 218 +/- 59 [mean +/- SD] microns), EES applied during the relative refractory period produced a linear and symmetrical profile of delta Vm/APA (-65 +/- 23% maximal hyperpolarization versus +64 +/- 15% maximal depolarization). In contrast, the profile of delta Vm/APA was asymmetrical when EESs were applied during the action potential plateau (-95 +/- 32% versus +37 +/- 14%). At high magnification, no secondary sources were observed at the borders between cells. In dense isotropic cell monolayers or in monolayers and strands showing intercellular clefts, secondary sources were frequently observed. Intercellular clefts of the size of one to several myocytes were sufficient to produce secondary sources of the same magnitude as those that elicited action potentials in dense cell strands. There was a close correlation between the location of secondary sources during EES and localized conduction slowing during propagation. Thus, densely packed cultured cell strands behave as an electrical continuum with no secondary sources occurring at cell borders. Small intercellular clefts can create secondary sources of sufficient magnitude to exert a stimulatory effect.

Animals↗
PubMed1996

[Immediate resection-anastomosis after intra-operative colonic irrigation in cancer of the left colon with obstruction].

In a consecutive series of 38 patients over 5 years, who required emergency surgery for obstructing left colonic carcinoma, 24 had primary bowel resection with immediate anastomosis, after intraoperative anterograde colonic irrigation. Complete colonic obstruction was present in all cases. There were 7 Dukes B tumors, 11 Dukes C tumors and 6 Dukes D tumors. The operative mortality was 8.3% (2 patients, with one from anastomotic leakage), anastomotic leakage rate was 4%. Superficial wound infection occurred in 4% of patients. The median postoperative hospital stay was 19.5 days. The Kaplan-Meier survival curve showed a 41% survival rate after 5 years. This technique was found to be safe and effective to perform a primary anastomosis, without requiring temporary colostomies, after emergency resection of selected left colonic carcinoma obstruction.

Aged↗
PubMed1996

[Physiology and pathophysiology of cardiac impulse conduction].

Representation of cardiac tissue by a continuous electrical cable provides a simple tool to explain impulse propagation and to make a comparison between heart, skeletal muscle and nerve. Recent experimental and theoretical studies have shown, however, that the process of electrical impulse propagation in heart is complex, due to the presence of cell borders and septa of connective tissue. At sites where propagation deviates from a linear profile, action potential generation gets delayed, and in cases of decreased excitability, unidirectional block may occur. At such sites, propagation is carried by the slow Ca++ inward current, in addition to the rapid Na+ inward current. As a consequence, local propagation may become sensitive to inhibition of Ca++ channels. Moreover, computer simulations have shown that electrical cell-to-cell uncoupling an gap junctions can reverse unidirectional block at such sites to bidirectional conduction. This complex interaction between function and structure which is likely to play a major role in remodeled tissue (hypertrophy, chronic infarction) has to be taken into account in the evaluation of the mechanisms of action of antiarrhythmic drugs.

Arrhythmias, Cardiac↗
PubMed1996

[Tonometric monitoring of the viability of free transplants of the jejunum and the stomach after total circulary pharyngolaryngectomy].

A prospective study concerning the tonometric viability supervision of 9 digestive free autografts after total pharyngolaryngectomy was conducted. This technic is based on the Henderson and Hasselbalch's equation which calculates the intramucosal pH (pHi) in the graft using a tonometric catheter. When the pHi is under 7.10, there is a graft ischemia. This invasive technique seems to be sensitive and specific provided that minimally rigorous measurement procedures are used. Late graft necrosis is the major limitation of the technique.

Adult↗
PubMed1995

Determination of impulse conduction characteristics at a microscopic scale in patterned growth heart cell cultures using multiple site optical recording of transmembrane voltage.

It is well established that impulse propagation in cardiac tissue is determined by the interaction between active membrane properties and the passive electrical characteristics of the network formed by individual myocytes. In the past, the intricate microarchitecture of intact cardiac tissue and the limited spatial resolution of available recording techniques had rendered a systematic evaluation of the influence of the cellular microarchitecture on impulse propagation difficult. Recently, however, successful efforts have been undertaken to: (1) simplify the cellular arrangement by designing cardiac structures with defined two-dimensional geometries; and (2) measure impulse propagation in these preparations at the cellular/subcellular scale using optical techniques. This short review considers both of these developments, i.e., patterned growth of heart cells in culture and multiple site optical recording of transmembrane voltage (MSORTV), and summarizes first results obtained with the combination of both techniques.

Animals↗
PubMed1995

[Retro-duodenal papillary perforation after endoscopic sphincterotomy. Role of surgical treatment by exclusion of the duodenum. Apropos of 3 cases].

Among the complications of endoscopic sphincterotomy whose rate is about 10% of cases, the retroduodenal papillary perforation represents about 1% of cases. The diagnosis lies on radiological examination which may show during the sphincterotomy the extravasation of the contrast fluid used for the retrograde cholangiography; it can be suggested by the presence of clinical signs of retroperitoneal sepsis or peritonitis. The treatment depends on the severity or peritonitis. The treatment depends on the severity of the clinical symptomatology; it is generally a medical treatment associating nasogastric aspiration and antibiotherapy, and more rarely a surgical one. There is no consensus concerning surgical modalities. We report 3 cases of retroduodenal papillary perforation treated surgical by a duodenal exclusion aiming to transform a complex fistula in a bilio-pancreatic fistula which can be more easily managed by somatostatine-like drugs.

Aged↗
PubMed1995

[Surgical treatment of adenocarcinoma of the stomach: 1969-1994. Apropos of 261 cases].

The study concerned 261 cases of gastric adenocarcinoma operated on between 1969 and 1994. Clinical, histological and therapeutic features were analyzed and compared during 3 periods (Group 1: 1969-78, Group 2: 1979-88, Group 3: 1989-94). The aim was to evaluate changes and results occurred in gastric carcinoma. The median age was 65 years (rage 25-90 years), the sex ratio, 1.9. The most common location was in the lower third of the stomach and the cancer was often far-advanced (73 percent of stages III and IV). Subtotal gastrectomy was replaced by total gastrectomy; the number of distal gastrectomy was unchanged. Large lymph node dissection was systematically performed in group 3. Curative resection rate increased from 28 to 51 percent between group 1 and group 3. Despite the more radical surgery, morbidity and post operative mortality rates decreased (respectively: 44.5%, 33%, 25.4%, and 22%, 10%, 7.2% for the groups 1, 2, 3, p < 0.01). 2-year survival rates were 20 percent for group 1, 25 percent for group 2 and 32 percent for group 3 (p < 0.01). This rates can be considered as satisfying in view of the high rate of III and IV stages.

Adenocarcinoma↗
PubMed1995

[True benign non-parasitic cysts of the spleen: from diagnosis to treatment. Apropos of 5 new cases].

True non parasitary splenic cysts are uncommon. They are characterized histological by an epithelium on the inner surface of the cyst wall. This study presents, about 5 new cases of splenic cysts, the clinical presentation, the difficulties of the diagnosis based on the ultrasound exploration and computed tomography scan investigation, and the different possibilities of management of these cysts. The principal of the treatment is the resection of the totality of a cyst with a diameter higher than 5 cm. A partial splenectomy seems to be the best treatment, whenever possible, especially in children.

Adolescent↗
PubMed1994

Delta-opioid receptor agonists inhibit neuromuscular transmission in human colon.

The present study was undertaken to investigate the possible role of delta-opioid receptors in the neuroregulation of human colonic motility by using a superfusion model. Spontaneous mechanical activity and responses to electrical transmural nerve stimulation of both longitudinal and circular muscle strips from the human sigmoid colon were studied. Exogenously added delta-opioid receptor agonists did not modify spontaneous contractile activities of either type of strip. Nerve stimulation induced a triphasic response composed of an initial contraction followed by a relaxation and an off-contraction. This response was mediated by cholinergic excitatory nerves and non-adrenergic, non-cholinergic excitatory and inhibitory nerves. [Met5]Enkephalin and the synthetic delta-opioid receptor agonist [D-Pen2,D-Pen5]enkephalin (DPDPE) significantly decreased the amplitude of the initial contraction and of the off-contraction. The effects of both delta-opioid receptor agonists were reduced in the presence of either the delta-opioid receptor antagonist, ICI 174864, or another delta-opioid receptor antagonist, naltrindole. ICI 174864 prevented neither the effects of a natural kappa-opioid receptor agonist, dynorphin-(1-13) nor those of the mu-opioid receptor agonist, PL017. Therefore, these data suggest that delta-opioid receptors might be involved in the neuroregulation of smooth muscle of human colon and may mediate inhibition of cholinergic and non-cholinergic excitatory transmission within the myenteric plexus.

Analgesics↗
PubMed1994

[Complicated colonic diverticulosis. Changes in treatment and results over 22 years].

OBJECTIVES: The aim of this study was to analyse the clinical course, surgical strategy and results in patients with complicated colonic diverticular disease. METHODS: We retrospectively compared two groups of patients who underwent surgery for complicated colonic diverticulosis from 1970 to 1984 (Group A, n = 94, mean age 60 years, 49 males, 45 females) and from 1985 to 1992 (Group B, n = 76, mean age 63.5, 32 males, 44 females). RESULTS: Patients in the two groups were comparable; only the rate of peritonitis (20 vs 8%) was different (p < 0.05). The most frequent operations in Group A were colostomy-drainage (43%) and Hartman's procedure (26%) in emergency situations and resection with immediate anastomosis (63%) or resection-anastomosis with diverting stomy (19%) in elective cases. In Group B, surgical strategy led to a different pattern of operations, 4 and 56% in emergency, and 94 and 2% in elective surgery, respectively. Overall mortality was 11%, with 17% and 4% in Groups A and B respectively (p < 0.01). This major drop in mortality was particularly important in emergency cases (31 vs 4%; p < 0.02). Morbidity in emergency surgery fell from 21 to 4% (P < 0.0006). Interrupting the use of colostomy-drainage was a major factor in reducing mortality followed by a sharp fall in mortality after Hartmann's procedure (28.5 vs 0%). CONCLUSION: The marked improvement in results between the two groups was mainly due to preferring resections of pathological colonic segments over colostomy-drainage.

Abscess↗
PubMed1994

Multiple site optical recording of transmembrane voltage (MSORTV) in patterned growth heart cell cultures: assessing electrical behavior, with microsecond resolution, on a cellular and subcellular scale.

We have applied multiple site optical recording of transmembrane voltage (MSORTV) to patterned growth cultures of heart cells to analyze the effect of geometry per se on impulse propagation in excitable tissue, with cellular and subcellular resolution. Extensive dye screening led to the choice of di-8-ANEPPS as the most suitable voltage-sensitive dye for this application; it is internalized slowly and permits optical recording with signal-to-noise ratios as high as 40:1 (measured peak-to-peak) and average fractional fluorescence changes of 15% per 100 mV. Using a x 100 objective and a fast data acquisition system, we could resolve impulse propagation on a microscopic scale (15 microns) with high temporal resolution (uncertainty of +/- 5 microseconds). We could observe the decrease in conduction velocity of an impulse propagating along a narrow cell strand as it enters a region of abrupt expansion, and we could explain this phenomenon in terms of the micro-architecture of the tissue. In contrast with the elongated and aligned cells forming the narrow strands, the cells forming the expansions were aligned at random and presented 2.5 times as many cell-to-cell appositions per unit length. If the decrease in conduction velocity results entirely from this increased number of cell-to-cell boundaries per unit length, the mean activation delay introduced by each boundary can be estimated to be 70 microseconds. Using this novel experimental system, we could also demonstrate the electrical coupling of fibroblasts and endotheloid cells to myocytes in culture.

Animals↗
PubMed1994

Characterization of impulse propagation at the microscopic level across geometrically defined expansions of excitable tissue: multiple site optical recording of transmembrane voltage (MSORTV) in patterned growth heart cell cultures.

Impulse propagation across sudden expansions of excitable tissue has been shown to exhibit various forms of conduction disturbance on a macroscopic scale, ranging from small delays to unidirectional or complete conduction block. With the present study, we attempted to characterize systematically the dependence of impulse propagation on the geometry of the underlying excitable tissue on a microscopic scale by investigating the spatio-temporal pattern of transmembrane voltage changes associated with impulse propagation from a narrow cell strand to a large cell area using multiple site optical recording of transmembrane voltage (MSORTV) in conjunction with patterned growth of neonatal rat heart cells in culture. While action potential propagation was smooth in the case of funneled expansions, delays of variable size occurred during propagation into rectangular or incised expansions. Close to the abrupt expansion, which functionally represented an increased electrical load to the narrow cell strand, the delays were accompanied by marked distortions of the action potential upstroke, exhibiting, in extreme cases, an initial depolarization to 50% followed by a delayed secondary depolarization to 100% of the full-signal amplitude. These distortions, which were based on bidirectional electrotonic interactions across the transition, were maximal immediately downstream from the expansion. The maximal slowing of impulse conduction across abrupt expansions was, in agreement with recently published results obtained from two-dimensional computer simulations, always situated in the expanded region. At high stimulation rates, the delays sometimes turned into intermittent unidirectional blocks, as revealed by reverse stimulation. These blocks were always characterized by a marked abbreviation of the action potentials upstream from the region causing the block which might, in an appropriate network, facilitate reentry because of the associated shortening of the refractory period. Because the patterns were composed of cells having identical membrane properties, the results show that the local action potential shape can be modulated profoundly by the two-dimensional architecture of the underlying cell ensemble alone.

Action Potentials↗
PubMed1994

[Pancreaticojejunal anastomosis by intussusception of an isolated loop in pancreaticoduodenectomy].

The most frequent and severe complication of pancreaticoduodenectomy is pancreatic fistula due to dehiscence of the pancreas anastomosis. The technique that uses a separate Roux en Y loop for pancreas anastomosis, to reduce the fatal risks of pancreatic fistula, has been described for more than 50 years. With the development of pancreaticogastrostomy, it seems interesting to present a procedure using an isolated loop for the pancreas; this technique, derived from those previously described allows a good intussusception of the pancreatic stump into the intestinal loop. This method was performed in 22 pancreaticoduodenectomies. There were 2 operative deaths unrelated to the pancreaticojejunal anastomosis and one pancreatic fistula, which healed under medical treatment.

Adult↗
PubMed1994

[Treatment of lithiasis of the common bile duct by endoscopic sphincterotomy and laparoscopic cholecystectomy].

This paper evaluates the treatment of common bile duct stones by endoscopic sphincterotomy (SE) and laparoscopic cholecystectomy (CL). 733 patients presenting with symptomatic cholelithiasis were operated on between March 1990 April 1993; 131 (18%) of them had a preoperative suspicion of common bile duct stones (LVBP): jaundice for 41, biliary acute pancreatitis for 27 and altered liver function tests for 63. 131 retrograde cholangiographies (CPRE) were attempted with an associated SE (113 cases) in the presence of LVBP, biliary pancreatitis, enlargement of common bile duct and appearance of forced papilla. CL was performed 24 to 48 hours later. CPRE +/- SE had no mortality; 1 patient presented a retroduodenal perforation of CBD, requiring surgery. 58 cases (44.2%) of LVBP were diagnosed, without a statistically significant difference according to the clinical pattern. In the group with altered liver function tests only alkaline phosphatase was significantly predictive of LVBP. There was no mortality or morbidity related to CL; conversion rate was 9.8%; 4 of 12 cases of conversion were related to persistence of stones in the common bile duct, without any possibility of laparoscopic extraction. Mean hospital stay was 7.4 days. Efficacy of this sequential method of treatment of LVBP was 91.3%: this method seems satisfactory, not dangerous and minimally invasive, and should be indicated for pre-operative suspected common bile duct stones.

Adolescent↗
PubMed1993

[1000 cases of cholecystectomy: 500 by laparotomy versus 500 by laparoscopy].

The authors report 1,000 cases of cholecystectomy for cholelithiasis, excluding all cases with associated common bile duct surgery. The aim of the study was to compare two groups of cholecystectomies, one of 500 laparotomic procedures, evaluated retrospectively, and one of 500 laparoscopic ones, evaluated prospectively. Sex ratio was the same in both groups, and mean age was higher in the second group (54 vs 60) (p < 0.05): acute cholecystitis ratio was similar in both groups (23% vs 19%; NS). During the laparoscopic period, 84 laparotomic interventions were performed (17%), with a 0% mortality and a 18% morbidity rate. Mean operating time was 69' in the first group vs 91' in the second one, with a mean hospital stay of 11 vs 4.5 days (p < 0.001). Mortality rate was 1% vs 0% (p < 0.03) for laparotomic and laparoscopic procedures, and morbidity rate was respectively 11% and 1% (p < 0.001). Conversion rate in laparoscopic surgery was 7%. Two cases (0.4%) in laparoscopic group had a common bile duct lesion diagnosed intraoperatively and 1 case (0.2%) had a residual stone in common bile duct. Laparoscopic surgery is at present the standard technique for the treatment of cholelithiasis and laparotomic cholecystectomy seems only indicated when laparoscopic procedure is contraindicated or impossible.

Adolescent↗
PubMed1993

[Parietal prosthetic mesh in the treatment of large incisional hernias].

The repair of abdominal wall deficiencies has been simplified by the introduction of synthetic prostheses. The aim of this work was to describe the treatment of very large incisional abdominal hernias with a technique using a prosthetic mesh anchoring to the fibro-aponeurotic layers without closure the fascia. The procedure described has been used in 32 cases between 1974 and 1991 (15 male, 17 female). The median age was 62 years. All the patients were reexamined (median time: 4 years, range: 6 months-14 years). There was no operative mortality. Six patients had a subcutaneous seroma treated by multiple punctions. Three patients presented in the postoperative time a respiratory failure which necessitated artificial ventilation during 7 to 15 day. Two patients were reoperated, 6 months and 3 years after the first incisional hernia operation (1 cutaneous fistula, 1 hernia recurrence). Extremely large incisional hernias can be closed safely and effectively using this technique, without mortality and with a low morbidity.

Aged↗