Microsurgical reconstruction of pancreatic ducts in dogs.

The incidence of traumatic injuries of the pancreas has increased in patients sustaining abdominal trauma. The purpose of this study was to perfect the microsurgical technique of anastomosis of pancreatic ducts in dogs as a contribution to conservative treatment of the injured pancreas with salvage of the spleen to avoid sepsis after splenectomy. Eighteen mongrel dogs weighing an average 20 kg were used. The anastomoses were performed with an operating microscope with monofilament nylon 10-0 (Ethilon) and polyglactin 910 (Vicryl) 10-0 (0.2 m) swaged to a BV-6 taper-point needle. Retrograde pancreatography was performed before and after operation. Serum amylase determinations were made. Histologic and scanning electron microscopic examinations of the anastomoses were performed at different intervals after operation. Primary healing occurred in all cases. Reepithelialization of the suture line was completed between the twenty-eighth and forty-second postoperative days. Patency of the pancreatic ducts was revealed by pancreatography 4 months after surgery. In conclusion microsurgery offers an interesting perspective to reconstructive pancreatic surgery.

Sex differences in nephrotoxic and gastrointestinal effects of phenylbutazone.

Male and female Wistar rats were used to study the sex differences in nephrotoxic, ulcerogenic and lethal effects of phenylbutazone (PBZ). In one series of experiments, male and female rats were given daily oral doses of 25, 125, 250, 400 and 500 mg PBZ/kg for 7 days to assess mortality, gross and microscopic lesions of the stomach, intestine and kidneys and to determine the PBZ effects on renal protein and glucose excretion. In another series of experiments, PBZ effects on renal gluconeogenesis and p-aminohippurate (PAH) accumulation in renal cortical slices were measured 12 h after administration of the same PBZ doses to male and female rats. Reduced glutathione (GSH) depletion and malondialdehyde (MDA) content in kidney cortex and liver were determined 2 h after a single administration of 250 mg PBZ/kg to male and female rats. To measure the effects of PBZ on blood urea nitrogen (BUN), male and female rats were given a single dose of PBZ (125 mg/kg) and were sacrificed at different time intervals, from 0 to 48 h. Gross and microscopic examination of the kidneys and gastrointestinal tract showed more pronounced renal and gastrointestinal lesions in surviving female than in male rats at the same doses. In PBZ treated male rats, BUN did not differ from control rats 48 h after PBZ administration. In female rats, BUN increased from 18 to 96 mg/100 ml 48 h after PBZ administration. After 7 days of PBZ treatment there was a greater increase of protein excretion in female than in male rats, but there were almost no sex differences in glucose excretion. Twelve hours after PBZ administration, renal PAH accumulation and gluconeogenesis were not different from controls in male rats but decreased in a dose-dependent fashion in females. A significant depletion of GSH and a significant increase in MDA content in liver and renal cortex occurred in female but not in male rats. In conclusion, the PBZ treatment was associated with nephrotoxic and gastrointestinal effects which could be detected earlier and were greater in female than in male rats.

[Starch granulomas caused by glove powder]. / Stärkegranulome durch Handschuhpuder.

Simultaneously with the introduction of new surgical gloves with heavily powdered outside surfaces, complications repeatedly occurred after laparotomies. Four patients were compelled to undergo a second operation, during which peritoneal fibrous adhesions and foreign body granulomas of omentum were found. After resection of the omentum, healing proceeded without disturbance. Five different types of surgical rubber gloves were examined by scanning electron microscopy. In addition, the effect was evaluated of different commonly applied preoperative rinsing procedures for gloved hands. The amount of powder found on the outside of regularly used gloves varied between 0.059 and 0.287 g. The effect on the proper healing process by starch powder deposits found on the outside of surgical gloves as well as upon optimal cleansing of the surgical teams' hands will be discussed.

Augmentation ileocystoplasty: an experimental study in dogs.

We report a technique of ileal augmentation cystoplasty allowing the tailoring of a "made-to-measure" cystoplasty of an adequate size with two or three ileal loops. The wound healing at the borderline between the bladder plate and the pediculated transplant is studied by light- and electron microscopic techniques.

[Bladder replacement by a continent ileocolonic intestinal reservoir wih antireflux-plasty--experimental study in the dog]. / Blasenersatz durch ein kontinentes ileocolisches Darmreservoir mit Antirefluxplastik--Experimentelle Studie am Hund.

The purpose of this experimental study was to try to develop a continent appliance-free urinary diversion with a non-refluxing urinary reservoir to be emptied by intermittent catheterization. A reliable antireflux plasty can be performed only on the large bowel wall. Continence can only be achieved using small bowel. For these reasons an ileo-colic urinary reservoir was conceived and experienced in 20 beagle dogs of both sexes. The posterior wall of the reservoir is formed by an intestinal plate constructed with two ileal loops. Continence is achieved by intussuscepting the terminal ileum in a retrograde fashion into the reservoir for a distance of 5 cm, thus creating a competent nipple valve between the pouch and the ileostoma. The anterior wall of the reservoir is formed using a colonic plate obtained by dividing the excluded sigmoid colon at the antimesenteric border. A long submucuous tunnel is created in the colon in which to lay the ureter. Thus renal infection and chronic pyelonephritis are avoided. Continence of the stoma is both socially and economically acceptable and improves the quality of life.

Microsurgical extramucous ureteroureterostomy in rats.

The purpose of this study was to perfect the microsurgical technique of ureteroureterostomy in rats as a contribution to reconstructive surgery of the urinary tract in congenital malformations in newborns and infants. Microsurgical ureteroureterostomy was performed in 100 rats with Nylon and Vicryl 10-0 and 11-0 swaged on a BV-6 and BV-8 needle. Postoperative investigation of renal function and permeability of the anastomoses was realized by macroscopic examination and by IM urography. The healing of the anastomoses was studied at different intervals after operation by histologic and scanning electron microscopic evaluation. Results include 1) per primam healing without stenosis in 98% of the cases; 2) urine proof anastomosis achieved to avoid scarification; 3) extramucous sutures preferable to prevent leakage and also crystallization that rapidly occurs in the rat and 4) tubing or nephrostomy is unnecessary.

Microsurgical reconstruction of the biliary duct: experimental study in rats and dogs.

Surgery of the biliary ducts remains a problem in traumatologic and iatrogenic injuries as well as in liver transplantation. The purpose of this study was to perfect microsurgical technique of anastomosis of the common bile duct and to study the healing and tissue reaction at the anastomotic site. The healing of microsurgical closure of longitudinal choledochotomies was studied as well. Light microscopic and scanning electron microscopic examination were performed at different intervals after operation. The permeability of the anastomosis was studied by transduodenal retrograde choledochography. Reepithelialization was obtained in 2 weeks. Microsurgery offers an interesting perspective to reconstructive biliary and transplantation surgery.

[Synthetic resorbable and synthetic non-resorbable suture materials in microvascular surgery. Animal experimental study]. / Synthetisches, resorbierbares und synthetisches, nicht resorbierbares Nahtmaterial in der mikrovaskulären Chirurgie--Tierexperimentelle Studie.

In a series of experiments on the aorta of the rat, the behaviour of an absorbable monofilament suture VICRYL (Polyglactin 910) was compared to that of a non-absorbable suture ETHILON (Polyamide 6/6). A total of 86 rats was operated upon and examined over a period of 70 days. The report includes a complete description of experimental procedures and techniques used during the operations. The evaluation of the experiments took place after completion of the mechanical, histological and scanning electron microscopical tests. It has been proven that under similar conditions, the 0,2 metric suture VICRYL has adequate tensile strength to withstand the intravascular pressure in a vessel with an outer diameter of approx. 1,5 mm. Aneurysm, stenosis and dehiscence of the anastomosis did not occur. The VICRYL suture showed no reactive processes after a period of 42 days. With the suture ETHILON the inflammation of the media and the hyperplasia of the intima persisted even after 70 days, at the end of the experiment. It is therefore shown in microsurgery, the monofilament absorbable suture VICRYL and the non-absorbable monofilament suture ETHILON are equal in their mechanical qualities, but that the suture VICRYL has by far the better tissue compatibility.

[The intratracheal behavior of the ear-composite graft. An experimental and histological study (author's transl)]. / Das intratracheale Verhalten des Haut-Knorpel-Transplantates aus der Ohrmuschel. Eine tierexperimentelle und histologische Studie.

The behavior of the composite graft obtained from the concha of the external ear is studied in mini-pigs, 25, 35, 46 and 85 days following transplantation into the tracheal wall by light- and electromicroscopy. The squameous cell epithelium persists to the same extent, but its thickness has decreased as well as desquamation by adaption to the intratracheal conditions. The transplanted cartilage started degeneration in the 4th postoperative week by a slowly and continous transformation into a granulating and fibrous tissue. The adjacent respiratory epithelium reacts by hypersecretion and by the increase of goblet cells. Therefore it may be differentiated from the transplanted squameous cell epithelium. The suture material vicryl is well tolerated causing only a slight reaction by the surrounding tissue, so far as the stitch is placed intraluminally through both, the transplant and the tracheal wall.

Early nephrotoxicity at high plasma concentrations of lysozyme in the rat.

In clearance experiments, egg white lysozyme was intravenously infused into male Wistar and Wistar/Furth rats over different periods of time to achieve plasma concentrations of lysozyme in the range of 30 to 8000 micrograms per ml. The glomerular filtration rate and the appearance of glomerular and tubular epithelia were comparable to those of control rats below 3000 micrograms per ml. of plasma concentration of lysozyme and up to 60 minutes' infusion time when investigated by scanning electron microscopy. A 50 per cent drop in blood pressure occurred at a plasma lysozyme concentration of 3000 micrograms per ml., which could be prevented by the intravenous injection of an antihistamine or by using Wistar/Furth rats; however, the decrease of the glomerular filtration rate and of the fractional lysozyme reabsorption as well as the increase in sodium and potassium excretion could not be avoided. After 30 minutes of lysozyme infusion, the epithelial foot processes exhibited slight regional effacement, and in more than 50 per cent of the tubules protein cast formation was noted. Occurrence of foot process effacement and tubular casts increased with further increase of plasma lysozyme concentration and lysozyme infusion time. These morphologic changes were common for Wistar rats, antihistamine-pretreated Wistar rats, Wistar/Furth rats, and in situ-perfused rat kidneys. These results indicate that the cationic low molecular weight protein lysozyme induced functional and structural alterations that were correlated with plasma lysozyme concentration and lysozyme infusion time and caused acute renal failure.

Microsurgical vasovasostomy.

Bilateral vasovasostomy was performed in 18 dogs and in 60 rats with Ethilon 10-0 and 11-0. The techniques used were: (a) a two-layer technique: the inner muscularis layer and the mucosal layer being sutured separately from the outer muscular layer; (b) a three-point one-layer technique: full-thickness stitches that traverse muscularis and mucosa at 120 degrees, 240 degrees and 360 degrees, between these three-point full-thickness stitches the muscularis layer is closed tightly. Patency of the vasal anastomosis was determined by injection of methylene blue and by vasography. Histologic and electron microscopic studies of specimens were performed at different intervals after the procedure. In a series of 25 rats, the results of the operation were determined by the biological fertility test: there was a 96% pregnancy rate.

PIP: Bilateral vasovasostomy was performed in 18 dogs and in 60 rats with Ethilon 10-0 and 11-0. The objective was an improvement of the technique by a 3-point anastomosis and a histologic and scanning electron microscopic study of vasovasostomy. The techniques used were the following: a 2-layer technique--the inner muscularis layer and the mucosal layer were sutured separately from the outer muscular layer; and a 3-point 1-layer technique--full thickness stitches that traverse muscularis and mucosa at 120 degrees, 240 degrees, and 360 degrees. Between the 3-point full thickness stitches the muscularis layer is closed tightly. The patency of the vasal anastomosis was determined by injection of methylene blue and by vasography. Histologic and electron microscopic studies of specimens were performed at different intervals after the procedure. Fertility was evaluated in 25 rats 4-6 months postoperatively by caging each operated male rat with 2 females with proven fertility for 14 days 3 times, at 4, 5, and 6 months postoperatively. Pregnancy occurred in 144 out of the 150 female rats, i.e., 24 operated male rats were fertile and 1 was sterile (96% fertility). 10 days postoperatively the wall of the vas was diffusely infiltrated with lymphocytes and histocytes. The Ethilon suture was surrounded by moderate tissue reaction. Histology and scanning electron microscopy results are also reported for 14, 18, 21, 25, 28, and 30 days postoperatively. At 25 days postoperatively the reepithelization is largely completed as visible on a longitudinal section shown in a figure. A moderate cellular infiltration is still visible. The inner layer of the vas consisted at this period of polygonal-shaped cells with distinct borders and scarcely spaced microvilli. At 28 and 30 days postoperatively the morphologic features were comparable to those during the previous period. The results of this experimental study displayed that a close and sperm proof approximation of the cut ends of the vas for refertilization can be obtained in dogs and rats by a 3-point anastomotic technique inserting a minimum of suture material into the lumen.

Thrombogenicity of different suture materials as revealed by scanning electron microscopy.

The thrombogenicity of five suture materials--polypropylene (Prolene), polyester (Mersilene), polyglactin 910 (Vicryl), nylon (Tthilon), and silk--was examined in vivo by scanning electron microscopy. The most blood-compatible material appeared to be Prolene. A rather satisfactory antithrombogenciity was shown by Mersilene, in comparison with which Ethilon and Vicryl provided less thromboresistance. The possible connection between the chemical changes which occur during the hydrolysis of Vicryl and its blood compatibility is discussed. Of the tested materials, silk proved to be the most thrombogenic. This study shows that the thrombogenicity of a suture material could be easily and conveniently tested in an experimental model by scanning electron microscopy, thus enabling the first choice of a suitable suture for the cardiovascular surgery, before one continues with other more sophisticated methods for the evaluation of thromboresistance.

Nephrotoxic effects of aminoglycoside treatment on renal protein reabsorption and accumulation.

To quantify the effects of gentamicin, kanamycin and netilmicin on renal protein reabsorption and accumulation, these drugs were administered to rats intraperitoneally (30 mg/kg/day) for 7, 14 or 21 days. Scanning electron microscopy of the glomerular endothelia, urinary measurements of sodium, potassium, endogenous lysozyme, N-acetyl-beta-D-glucosaminidase (NAG) as well as clearance and accumulation experiments after i.v. administration of egg-white lysozyme and measurements of inulin clearance (GFR) were done in each treatment group. Gentamicin administration decreased diameter, density and shape of endothelial fenestrae. Kanamycin and netilmicin appeared to have no effect at the dose used. All three aminoglycosides decreased GFR and increased urinary excretion of sodium and potassium. While gentamicin and kanamycin decreased the percentage reabsorption and accumulation of lysozyme after i.v. administration of egg-white lysozyme netilmicin had no effect. Daily excretion of total protein, endogenous lysozyme and NAG increased only after treatment with kanamycin and gentamicin. Thus, aminoglycosides may act as nephrotoxicants at glomerular and/or tubular level inducing impairment of renal reabsorption and accumulation of proteins.

[Demonstration of neo-intima in PTFE-prostheses after venous replacement in dogs]. / Neo-Intima-Nachweis nach experimentellem Venenersatz durch PTFE-Prothesen beim Hund.

Because of the danger of thrombosis, venous replacement by prostheses is a yet clinically unsolved problem. We tested the PTFE-prosthesis at the positions of vena cava inferior and iliac veins in dogs. Already eight weeks after operation, the inner surface of the prosthesis was covered by a thin neo-intima, which by light microscopy, scanning and transmission electron microscopy was shown to contain a basal membrane and endothelial cells. This continuous layer may be responsible for the observed low rate of thrombosis. These findings suggest that the PTFE-prosthesis may offer advantages for venous replacement in patients.

Effects of aminoglycosides on glomerular permeability, tubular reabsorption, and intracellular catabolism of the cationic low-molecular-weight protein lysozyme.

Gentamicin and other aminoglycoside antibiotics in high doses may produce proteinuria and other signs of nephrotoxicity. Proteinuria may result from general renal damage or may reflect alterations in specific steps in the renal handling of proteins. To distinguish between these two possibilities, experiments were designed to quantify the effects of nephrotoxic doses of several aminoglycosides on the renal handling of proteins in the isolated perfused rat kidney with the cationic low-molecular-weight protein lysozyme as a representative protein. Each aminoglycoside was administered ip to male Wistar rats (30 mg/kg/day) for 7 days. Lysozyme and 125I-lysozyme were added to the perfusate to achieve a lysozyme perfusate concentration of about 100 mg/liter. Clearances of inulin and lysozyme, release of tyrosine and trichloroacetic acid-soluble radioactive metabolites into the perfusate, and the glomerular sieving coefficient of lysozyme were determined. Scanning and transmission electron microscopy indicated that gentamicin and tobramycin decreased the number and diameter of the endothelial fenestrae of the glomerular capillaries. Concurrently, gentamicin and tobramycin decreased the glomerular sieving coefficient of lysozyme from 0.8 to 0.6 and 0.5, respectively. Netilmicin did not affect the percentage reabsorption of lysozyme whereas gentamicin and tobramycin decreased lysozyme reabsorption from 71.7 to 35.4 and 34.4% of the filtered load, respectively. Lysozyme degradation, estimated by the release of tyrosine into the perfusate during a 150-min perfusion period, was decreased from a control value of 12 mumol/liter to 4.43 and 4.65 mumol/liter in kidneys from rats treated with gentamicin and tobramycin, respectively. This study demonstrates that polycationic aminoglycosides may affect several processes involved in renal handling of lysozyme including glomerular permeability, tubular reabsorption, and intracellular proteolytic degradation.

Effects of aminoglycosides on glomerular ultrastructure.

Effects of the aminoglycosides, gentamicin, netilmicin and tobramycin (30 mg/kg/day X 7, i.p.), on glomerular ultrastructure were determined in male Wistar rats. Glomerular ultrastructure was studied by scanning and transmission electron microscopy. The average number of capillary endothelial fenestrae per 5 microns of capillary wall decreased from a control value of 10.8 to 8.2 and 8.1 in gentamicin- and tobramycin-treated rats, respectively, as shown by transmission electron microscopy (TEM). Scanning electron microscopy (SEM) showed that the density of endothelial fenestrae decreased to about 80% of control in gentamicin- and tobramycin-treated rats. In addition, gentamicin and tobramycin produced a marked reduction in the number of granulated myoepithelioid++ cells of the juxtaglomerular apparatus. Netilmicin appeared to have no effect on glomerular ultrastructure. Both TEM and SEM, indicate that the nephrotoxic aminoglycosides gentamicin and tobramycin alter the ultrastructure of the fenestrated endothelia of the glomerular capillaries. These ultrastructural changes appear to be correlated to the impairment of the glomerular permeability for different compounds.