Preliminary report: a new technique of enterotomy closure using Nd:YAG laser welding compared to suture repair

This study compared the histology and tensile strength of Nd:YAG laser welded and sutured small bowel enterotomies in Sprague-Dawley rats. Enterotomies (0.5 cm long) were either welded with the Nd:YAG laser (1 W and 10.6 sec pulses) or repaired with interrupted, simple 6-O silk sutures. Group I consisted of seven animals; five with enterotomies repaired by laser welding and two repaired by suturing. Group II consisted of eight animals with each having both laser and suture repairs. Animals were killed and specimens were removed and examined at 1 day, and at 1, 2, and 3 weeks postoperatively to compare the progression of healing. On macroscopic examination the laser welded enterotomies were closed 84% of the time and only 23% had adhesion formation while 90% of sutured repairs were closed and 100% had adhesion formation. Histologic examination of both suture and laser welded enterotomies demonstrated active healing at 1 week with minimal collagen bridging the enterotomies. At 2 and 3 weeks the sutured enterotomies had granulomatous reaction around the sutures while the laser welded enterotomies had minimal inflammatory response and near normal small bowel histology. The tensile strength of the 3-week specimens from both the suture and laser welded enterotomies were 50% of normal bowel. These findings suggest that the laser welding of small bowel enterotomies is comparable in closure and tensile strength to suture repair. The time required to repair the enterotomy is significantly decreased, the procedure is easily performed, and there is a marked decrease in adhesion formation following laser repair.     

Closure of rabbit ileum enterotomies with the argon and CO2 lasers: bursting pressures and histology

In this study, we examined short-term strength and histology of experimental argon and CO2 laser-welded and control-sutured enterotomies in a rabbit model. Longitudinal 1.0-cm enterotomies were closed with the argon laser at 0.5 (n = 10) or 1.0 (n = 10) W power and a spot diameter of 2.8 mm resulting in energy fluences of 230 and 450 J/cm2, respectively. Similar enterotomies were closed using the CO2 laser at 0.5 (n = 10) or 1.0 (n = 10) W power and a spot diameter of 1.2 mm, resulting in energy fluences of 1,360 and 2,730 J/cm2. In all closures, continuous wave laser was delivered for 30 seconds. Using a pressure-monitored infusion system with normal saline, the pressure required to burst each weld as well as sutured controls (n = 10) was recorded approximately 1 minute following fusion. Mean bursting pressures for the argon laser at 0.5 W and 1.0 W were 34.1 +/- 19.4 mm Hg (mean +/- SD) and 17.3 +/- 8.3 mm Hg, respectively, and for the CO2 laser were 23.5 +/- 12.0 mm Hg and 31.8 +/- 15.6 mm Hg, respectively. Sutured controls leaked at 45.2 +/- 12.0 mm Hg. With the exception of argon-laser welds at an energy fluence of 450 J/cm2, which were less than sutured repairs, the bursting pressures for welded closures were not significantly different from the sutured controls (Student's t distribution, P less than .05). Histologic examination of both types of welds demonstrated a fibrin and red blood cell coagulum bridging the anastomosis, with some evidence of mild thermal injury at the mucosa.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bursting pressures of CO2 laser-welded rabbit ileum

In this study, the short-term bond strength of laser-welded New Zealand white rabbit ileum was examined. Forty-eight longitudinally oriented 0.5-cm transmural, scalpel incisions were reanastomosed solely through the use of the CO2 continuous wave laser at low energy levels. Random power levels of 250, 500, 750, or 1,000 mW were delivered to weld sites by either continuous application for 30 seconds or a pulsating application (ie, 0.5 seconds on, 0.5 seconds off) for 60 seconds. This provided 53.6, 107.1, 160.7, and 214.3 J/cm2, respectively. With the aid of a plexiglass clamp and pressure monitored infusion system, each type of weld was tested six times to determine the intraluminal hydrostatic pressure required to burst the welded seam 1 minute after completing the weld. For the welds made with 107.1, 160.7, and 214.3 J/cm2 in both lasing modes, the mean bursting pressure was 40.7 mmHg (SD +/- 24.9) with no statistically significant difference in weld strengths at these energy densities. There was also no difference between continuous and pulsating delivery methods. However, the energy density of 53.6 J/cm2 in either method produced a mean bursting pressure significantly lower than those produced by the higher energy densities tested and below the estimated basal ileal intraluminal pressure of approximately 9 mmHg. Since 107.1 J/cm2 energy density caused the minimal gross tissue changes while producing an equally strong bond and since continuous is faster than pulsating, 500 mW of continuous delivery was considered the optimal setting for the CO2 laser welding of rabbit ileum.     

Gaslose videoendoskopische Implantation aortobifemoraler Gefäßprothesen über einen extraperitonealen Zugang im Tierversuch

The gasless videoendoscopic implantation of GELSOFT aortobifemoral vascular prostheses times 6×6 mm in diameter using an extraperitoneal approach was tested in ten porcine experimental models at the Surgical Department of the University of Cologne, Germany. Gasless videoendoscopic surgery is performed with a laparolift-laparofan system. Aortobifemoral GELSOFT prostheses were successfully implanted in nine of ten animals, whereby one animal died during preparations for surgery of massive coronary infarctions. Average surgical durations using the extraperitoneal approach were 270 min. Dissection of the infrarenal aorta until occlusion took 45 min, average aortic occlusion 75 min, and iliacofemoral occlusion 45 min for the left side and 75 min for the right side. After successful videoendoscopic implantation of aortobifemoral GELSOFT prostheses all nine animals underwent laparotomy and resection of the aortobifemoral prosthetic segment. The quality of the endoscopically sutured aortic end-to-side anastomoses was examined in vitro under artificial circulation of glycerol/Ringer's lactate solution for evaluation of possible leakage and bursting pressures and then compared to conventionally sutured end-to-side anastomoses of 6-h-old porcine abdominal aorta and GELSOFT prostheses 6 mm in diameter. The maximum bursting pressure of all endoscopically sutured anastomoses was 480 mmHg mean pressure; the minimum was 140 mmHg mean pressure. The minimum leakage per minute was less than 10 ml/min for systolic pressure values between 120 and 350 mmHg. All endoscopically sutured aortic end-to-side anastomoses were comparable to conventionally sutured anastomoses concerning in vitro evaluation of bursting pressure and leakage per minute.     

Reinforcement of colonic anastomoses with a laser and dye-enhanced fibrinogen

The incidence of anastomotic leakage in colonic surgery is approximately 10%. We evaluated a technique of laser-fibrinogen reinforcement to strengthen experimental colonic anastomoses. The technique consisted of the topical application of indocyanine green dye-enhanced fibrinogen to the serosal surface of two-layer inverting anastomoses, followed by exposure with an 808-nm diode laser. In the 28 rabbits used for this study, mean bursting pressure at time 0 was 108 +/- 13 mm Hg in the group receiving anastomoses with sutures alone and 173 +/- 20 mm Hg in the group for which the sutured anastomosis was reinforced with laser-fibrinogen. The difference in bursting pressures between the two groups was statistically significant at time 0. However, at 1, 3, 5, and 7 days, the anastomosis became stronger in both groups and the difference in strength was reduced; the sutured group had more exceptionally weak (less than 110 mm Hg) bonds than the group treated by laser. Thus, laser-fibrinogen reinforcement significantly enhances the early strength of sutured colonic anastomoses. This technique may reduce the incidence of leakage during the first postoperative week and the associated complications in a clinical setting.     

Tissue soldering by use of indocyanine green dye-enhanced fibrinogen with the near infrared diode laser

Anastomoses welded by laser have been strengthened by applying a solder of fibrinogen combined with a laser energy absorbing dye (indocyanine green, maximum absorbance 805 nm) to the anastomotic site before continuous-wave diode laser exposure (808 +/- 1 nm, 4.8 W/cm2). Immediately after creation, the bursting pressures of welds created without fibrinogen (262 +/- 29 mm Hg, n = 11) were significantly less than repairs with fibrinogen (330 +/- 75 mm Hg, n = 11) (p less than 0.05). When repairs performed with fibrinogen were exposed to urokinase (25,000 IU) the bursting pressures were not significantly different from baseline (290 +/- 74 mm Hg, n = 5). Aortotomies closed by suture did not burst but leaked at pressures significantly below those of vessels closed by laser (165 +/- 9 mm Hg, n = 11) (p less than 0.01). Twenty-two repairs soldered with fibrinogen were incorporated into survival studies in rabbits and examined from 1 to 90 days after operation. No anastomotic ruptures, thromboses, or aneurysms were identified. Soldered sites rapidly regenerated a new intimal surface and healed by myofibroblast proliferation. No significant foreign body response was identified; the fibrinogen was resorbed. Laser soldering with exogenous fibrinogen is feasible without topical administration of additional clotting agents, significantly improves the bursting strength of primary laser welded anastomoses, and appears to result from urokinase-resistant fibrinogen cross-linking.     

Experimental evaluation of the mechanical strength of stapling techniques

Background The single stapling technique (SST) and the double stapling technique (DST) are common anastomoses for rectal cancer. Although many mechanical devices have been developed, the best choice remains unclear. In this study we examined the strength of anastomoses by determining their bursting pressures using an animal model. Methods The intestines of pigs were used. In experiment 1, we compared the bursting pressures for Endo GIA™ 60 blue, Endo GIA™ 60 green, and GIA™ 60 blue. In experiment 2, the bursting pressures of a buttressed cutting site and a nonbuttressed cutting site were measured. In experiment 3, the SST, DST, and DST with buttress using PCEEA™ were performed and the bursting pressures and points of these anastomoses were examined. Results The bursting pressure of Endo GIA 60 blue (80.3 ± 10.5 mmHg) was significantly higher than that of Endo GIA 60 green (37.3 ± 4.2 mmHg) and GIA 60 blue (31.7 ± 5.8 mmHg) (p < 0.01). When a cut end was buttressed, the bursting pressure (149.6 ± 37.6 mmHg) was significantly higher than that of the nonbuttressed end (75.3 ± 25.1 mmHg) (p < 0.01). The bursting pressure among SST, DST, and DST with buttress was not significantly different. Only one bursting point was the crossing point of the PCEEA and Endo GIA and the bursting pressure of this point was much lower than that of the others. Conclusion Endo GIA was most suitable for DST. The SST, DST, and DST with buttress had almost the same strength. The crossing point of PCEEA and Endo GIA may be a dangerous point for DST.     

Suture-Free Small Bowel Anastomoses Using Collagen Fleece Covered with Fibrin Glue in Pigs

Background: Several studies investigating anastomotic healing could objectify that the regularly used suture material leads to an impairment of wound healing due to ischemia at the anastomotic line. This study was initiated to test a hypothesis that a reduction of suture material leading to suture-free glued intestinal anastomoses is feasible and enables an improved wound healing. Materials and Methods: Three different types of anastomoses were carried out at the small bowel of 16 pigs. Standard hand-sewn anastomoses, anastomoses with loose-fitting skin staples, and suture-free glued anastomoses using a fibrin covered collagen fleece. When the animals were killed, both gross inspection of the parietes, bursting pressure and tissue for histological study became the basis for evaluation. Analyses were also made regarding the collagen I/III ratio and the expression of MMP 1 and 13. Results: Four leakages at the stapled, one at the sutured, and one at the glued anastomoses occurred. All other anastomoses healed without complications. The bursting pressure did not differ significantly between the groups. The macroscopic inspection and the microscopic examination both showed an improved healing pattern for the material reduced techniques without onset of a deep ulcer at the anastomotic line as seen at the conventional sutured anastomoses. These findings were supported by the immunohistochemical studies. Conclusions: These observations suggest that a suture-free bowel anastomoses using collagen fleece covered with fibrin glue is technically feasible. Obviously, a reduction of foreign body material at the anastomotic line avoids unnecessary ischemia and thus supports a physiological improved wound healing process.     

Effects of electrocautery, CO2 laser, and contact Nd:YAG laser scalpel on the healing of intestinal incision

Leakage after intestinal resection is a serious complication with a high mortality rate. A recent study claims that cutting the intestine with the CO2 laser improves the healing of intestinal anastomoses (Ferulano et al: Eur Surg Res 16:127-130, 1984). The present study was undertaken to analyze the effects of electrocautery, CO2 laser, and contact Nd:YAG laser on the healing of intestinal incisions. Fifteen piglets were used and the cutting and reanastomosing were performed by using all cutting methods in each animal in randomized order. Resection sites were 50 cm, 100 cm, and 150 cm distal to the ligament of Treitz. On the seventh day the bursting pressures were measured for each anastomosis. They were 172 +/- 17 mmHg for normal bowel segment and 133 +/- 12, 135 +/- 40, and 139 +/- 17 mmHg for electrocautery, CO2 laser, and Nd:YAG laser, respectively. There were no mortality, no anastomotic leaks, and no statistically significant differences in the bursting pressures, in histology, or in the healing of anastomotic sites, indicating that electrocautery, CO2 laser, and contact Nd:YAG laser scalpel can safely be used in the surgery of small intestine.     

Comparative In Vitro Study of Tissue Welding Using a 808 nm Diode Laser and a Ho:YAG Laser

In vitro porcine arteries and veins have been welded end-to-end using either a 808 nm diode laser combined with an indocyanine green enhanced albumin solder, or with a continuous-wave (cw) Ho:YAG laser without biological solder. The vascular stumps were approached to each other over a coronary dilatation catheter in order to obtain a precise alignment and good coaptation. Standard histology revealed for both welding techniques lateral tissue damage between 2 and 3 mm caused by laser-induced heat. Good solder attachment to the tissue was observed by the use of a scanning electron microscope. The vessels soldered with the 808 nm diode laser using albumin solder showed considerably higher tensile strength (1 N compared to 0.3 N) than vessels welded exclusively by Ho:YAG laser radiation. In contrast, leaking pressure (350±200 mmHg) and bursting pressure (457±200 mmHg) were found to be independent of the welding technique used. This study demonstrates that fast (total welding time about 2–5 min), stable and tight microvascular anastomosis can be achieved with the use of a dye-enhanced albumin laser soldering technique and an ancillary coronary dilatation catheter. Paper received 10 August 2000; accepted after revision 3 January 2001.     

Sutureless End-to-End bowel anastomosis using Nd:YAG and water-soluble intralurninal stent

Sutureless end-to-end intestinal anastomoses were successfully constructed in 20 rabbits. A water-soluble intraluminal stent was used to approximate the tissue edges, and the anastomotic seam was lased with 1.06 μm neodymium:YAG (Nd:YAG) laser energy supplied through a hand-held 600-μm gas-cooled noncontact optical fiber. A continuous 5-watt wave of power was applied over periods ranging from 46 to 92 seconds to produce the tissue blanching and shrinkage that indicated a satisfactory tissue weld. Integrity, degree of tissue reaction, and bursting pressures of the anastomoses were compared to those of anastomoses constructed using standard sutured techniques. The results of the two methods were equivalent at 1 to 3 days, but the laser-fused enteric anastomoses showed less inflammatory reaction and greater bursting pressures at 7 and 14 days. Application of a variety of proteinaceous solutions including extracellular matrix materials and epidermal growth factors prior to lasing failed to augment wound healing. We conclude that lasers show promise as reconstructive, in addition to ablative, surgical instruments.     

Effects of locally applied recombinant human granulocyte-macrophage colony-stimulating factor on ischemic bowel anastomoses in rat

BACKGROUND: Ischemia is one of the most common causes of anastomosis disruption. In the present study we investigated the effect of locally injected recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on ischemic bowel anastomosis in rats. METHODS: 144 male Sprague-Dawley rats were randomized into four groups: in group 1, colon anastomoses were performed; in group 2, anastomoses were performed then 50 microg rhGM-CSF was injected subserosally into the perianastomotic area; in group 3, anastomoses were performed on ischemic colon segments, and in group 4, colon anastomoses were performed on ischemic segments and then 50 microg rhGM-CSF was injected subserosally into the perianastomotic area. On the 3rd and 7th post-operative days, the rats were sacrificed and anastomotic bursting pressures were measured. Hydroxyproline contents were studied on the tissues from the anastomotic line. Three anastomotic segments were saved from each group for histopathological studies before bursting pressure measurement. RESULTS: The bursting pressure in group 3 was significantly weaker than in the other groups. There were no significant differences between the bursting pressures in groups 1 and 4. The levels of hydroxyproline content in group 4 were significantly greater than in group 3. CONCLUSIONS: These data suggest that the local injection of rhGM-CSF improves the healing of ischemic and even normal colon anastomoses.     

Canine colonic anastomoses reinforced with dye-enhanced fibrinogen and a diode laser

Summary Leakage from colonic anastomoses is a common cause of morbidity in patients recovering from bowel surgery. We evaluated a technique of laser-fibrinogen reinforcement to strengthen colonic anastomoses in a canine model. After creation of eight single-layer interrupted suture anastomoses in six dogs, indocyanine green-dye-enhanced fibrinogen was topically applied to the serosal surface and exposed to 808 mm diode laser energy. Immediately following colonic anastomosis, the mean leakage pressure was 137±22 mm Hg in the group (n=8) using sutures alone and 326±67 mm Hg (P<0.001) in the group (n=8) after the sutured anastomosis was reinforced with lasered-fibrinogen. On histological examination, no evidence of thermal injury to the tissue edges was noted and a layer of fibrinogen bridged the anastomotic gap. Laser dye-enhanced fibrinogen reinforcement significantly enhances the strength of sutured colonic anastomoses without causing appreciable thermal injury to the host tissues.     

In vitro bursting strength studies of laser-welded tissue and comparison with conventional anastomosis

We compared the mechanical integrity of microvascular anastomoses created with a carbon dioxide (CO2) laser with conventional suture anastomoses. Seventy rat femoral artery segments (35 lased and 35 sutured) were harvested at 1, 24, and 72 hours, and 1, 3, 6, and 12 weeks postoperatively. These segments were subjected to increasingly higher in vitro intraluminal hydrostatic pressures (bursting pressure). Conventionally sutured anastomoses exhibited significantly increased ability (p less than 0.05) to withstand greater bursting pressures than the laser-welded tissue up to 3 weeks postoperatively. After the third postoperative week, the laser anastomoses demonstrated increased bursting pressures compared with the conventional anastomoses. At the end of the 12-week period both groups demonstrated an ability to withstand supraphysiologic pressures in excess of 2000 mm Hg.     

Failure testing cerebral arteries: are branch points weaker than unbranched vessels?

The bursting pressure of samples of cerebral arteries was measured. Eighty-five samples of cerebral arteries were taken from 11 fresh cadavers. These samples were filled with saline under pressure to the point of bursting. The bursting pressures were recorded. The mean bursting pressure of all samples was 1.8 bar (1370 mmHg). The range was 0.7-4.6 (530-3190 mmHg). The mean bursting pressures of samples containing branch points was 1.6 and that of those without branch points was 2.2. This difference was significant with p < 0.001. Samples taken from persons dying from subarachnoid haemorrhage were weaker (mean 1.45 bar) than those taken from persons dying from other causes (mean 1.971 bar). This difference was significant with p < 0.001. Bursting pressure was found to decline at 2% per year of age. This figure was different from 0 with p = 0.003.     

The prevention of post-operative adhesions using a gastrointestinal prokinetic agent

Attempts have previously been made to reduce adhesion formation by promoting early intestinal motility. The prokinetic agent Cisapride was used in an animal model of end-to-end large bowel anastomoses. Twenty Wistar rats receiving Cisapride 1 mg/kg subcutaneously (sc) twice daily for two days post-operatively were compared with 20 controls receiving saline 0.2 mL in a similar regimen. The points of adhesion of the anastomosis to the following structures were enumerated: tubal fat; mesentery; omentum; caecum; small bowel; and abdominal wall. The treatment group had significantly fewer adhesions: 2.8 +/- 0.9 v 4.3 +/- 1.0. This was mainly in the number of small bowel attachments, 3.8% compared with 37.8%. The study was repeated using small bowel anastomoses. Cisapride again reduced the number of adhesions compared with controls: 2.1 +/- 0.4 v 4.2 +/- 1.4. Cisapride therapy resulted in greater post-operative stool weights and food consumption: control, 3.87 +/- 1.1 stool, 17.04 +/- 4.3 g food; Cisapride 4.43 +/- 0.9 g stool, 19.8 +/- 4.7 g food. The enhanced motility did not affect the anastomotic strength of the small bowel; bursting pressures at a constant inflation rate of 1.1 mL/min were: control 212.8 +/- 56.0 mmHg; Cisapride, 215.8 +/- 58.9 mmHg (NS).     

Laser welded vesicourethral anastomosis in an in vivo canine model: a pilot study

PURPOSE: We evaluated laser welding as an alternative method of forming the vesicourethral anastomosis. MATERIALS AND METHODS: Eight dogs underwent open total prostatectomy, including 4 in which the vesicourethral anastomosis was formed by 830 nm. diode laser welding using a chromophore doped albumin solder and 3 or 4 support sutures. The remaining 4 anastomoses were conventionally formed using 8 interrupted sutures. Acute leakage was tested intraoperatively. The anastomosis of 1 animal per group was assessed on postoperative days 3, 5, 7 and 14 by radiography before sacrifice. Each anastomotic specimen was then tested for leak pressure and examined histologically. RESULTS: There were no leaks during intraoperative testing of laser welded or sutured anastomoses. On radiography there were no leaks in the laser welded group. In 1 control there was slight localized leakage. All anastomoses achieved physiological leak pressures of 70 mm. Hg or greater with 3 of the 4 in the laser welded group recording supraphysiological pressures of greater than 200 mm. Hg. While 3 of the 4 laser welded specimens showed evidence of muscle necrosis, there were no other differences in healing in the 2 groups. CONCLUSIONS: These short-term results suggest that diode laser welded vesicourethral anastomosis is feasible. This technique has the potential to simplify anastomotic formation in laparoscopic radical prostatectomy, shortening operative time. Diode laser welding in this small cohort created an immediate and ongoing watertight anastomosis and, therefore, it may also be an alternative in open radical prostatectomy cases. Further study is needed to assess long-term effects on healing.     

The effects of increased intraabdominal pressure on colonic anastomoses

Background: This experimental, randomized, controlled study was designed to investigate the effects of increased intraabdominal pressure (IAP) on colocolic anastomoses. To our knowledge, this is the first study to address this important issue. Methods: For this study, 50 Wistar albino rats were randomized into five groups. The animals in all the groups underwent laparotomy and colocolic anastomosis. The rats in the control group were not subjected to increased IAP. Accordingly, IAP's of 14, 20, 25, and 30 mmHg were established by carbon dioxide insufflation and maintained for 60 min in study groups 1, 2, 3 and 4, respectively. Colocolic anastomosis was realized after these periods of IAP in the study groups. Half of the surviving rats in all the groups were sacrificed on postoperative days 7 and 14 to allow comparison between the control and study groups with respect to their mean body weights, mean anastomosis bursting pressures, and histopathologic characteristics of their anastomosis sites. Results: The mean body weights of all the groups were comparable at all times during the study. The anastomosis bursting pressures of the animals subjected to increased IAP were lower than that of the control group, with the differences reaching statistical relevance for the animals subjected to an IAP of 20 mmHg or higher on postoperative day 7 (p <0.0005 for study groups 2, 3, and 4 vs the control group) and becoming more pronounced by the day 14 (p <0.0005 for study groups 2, 3, and 4 vs the control group). The anastomosis bursting pressure showed an inverse correlation with IAP. The adequacy of mucosal layer formation at the anastomosis line was lower and the degree of inflammation was higher in the groups exposed to an IAP of 20 mmHg or higher in the control group (p <0.05 for both comparisons among study groups 2, 3 and 4 vs the control group). Conclusions: An IAP increased to 20 mmHg and higher was found to result in impaired strength and wound healing in colocolic anastomoses, as reflected by the decreased bursting pressure and mucosal layer formation, and by the increased inflammation at the anastomosis sites of animals subjected to high IAP values.     

Metastasis of Vulvar Cancer in the Breast

Background : Several researchers have investigated how wound healing is effected by supplementation with each of the following amino acids: arginine (Arg), glutamine (Glu), and β-hydroxy β-methylbutyrate (HMB). This research investigates how a combination of these amino acids improves the wound healing associated with anastomoses. Methods : We tested the effects of a combination of Arg, Glu, and HMB on the healing of colon anastomoses in 50 male rats. We randomly divided the animals into two equal groups. In each animal, the cecum was transected from its midpoint to create an end-to end anastomosis. During the first postoperative week, Group 1 (G1) animals were fed standard chow, and Group 2 (G2) animals were fed standard chow plus a ready-to-use supplement that contained a mixture of Arg, Glu, and HMB. At the end of the week, all of the rats were sacrificed, and a cecum segment containing the anastomosis line was resected. Bursting pressure and tissue hydroxyproline were measured for all animals.

Results : The mean values for hydroxyproline were 0.0013 ng/mg protein/ml (SD ± 0.00075) and 0.034 ng/mg protein/ml (SD ± 0.022) for G1 and G2, respectively (p < 0.0001). The mean values for bursting pressure measurements were 122.8 mmHg (SD ± 9.4) and 192.8 mmHg (SD ± 31) for G1 and G2, respectively (p < 0.0001). Statistically significant differences between the groups in terms of both bursting pressure levels and tissue hydroxyproline levels were observed. Conclusion : In an animal model of colon surgery, supplementation with a combination of three amino acids seemingly benefits anastomosis healing.     

Enterotomy fusion with laser energy: preliminary results in rabbit ileum

The utility of enterotomy closure with the argon and CO2 lasers was examined in New Zealand white rabbit ileum. Thermal properties of 10 argon (0.5 W power for 30 s, energy fluence 230 J/cm2) and 10 CO2 (1.0 W power for 30 s, energy fluence 2700 J/cm2) laser-fused enterotomies were determined during acute fusion experiments using an AGA 782 digital thermographic camera. Healing of the fusions created by the two lasers was subsequently assessed in an additional group of 28 rabbits by comparing three 1.0-cm longitudinal ileal enterotomies, with each rabbit having both types of laser-welded closures and a sutured control. Thermal measurements made from the 10 closures with each laser revealed that the CO2 fusions generated significantly higher temperatures (max. 198 degrees C, mean 106 +/- 37 degrees C, n = 100) than argon (max. 85.2 degrees C, mean 60.5 + 8.1 degrees C, n = 100) p less than 0.001. In the healing studies, four rabbits died from weld failures (one argon and one CO2 disruption, two rabbits with both welds disrupted). Two additional rabbits died at 1 day and one at 10 days for undetermined reasons. The remainder of the animals were sacrificed at 1 (n = 11), 2 (n = 2) and 4 (n = 9) weeks postoperatively. Sutured closures exhibited more granulation tissue and adhesions surrounding the wounds than did welded closures and seven microabscesses were noted adjacent to sutured repairs. One of the CO2 repairs had an abscess at 4 weeks and none of the argon laser fusions had evidence of disruption or abscess.(ABSTRACT TRUNCATED AT 250 WORDS)