An absolute measurement of brain water content using magnetic resonance imaging in two focal cerebral ischemic rat models.
(9/573)
Magnetic resonance imaging (MRI) was utilized to obtain absolute estimates of regional brain water content (W), and results were compared with those obtained with conventional wet/dry measurements. In total, 31 male Long-Evans rats were studied and divided into two groups based on the surgical procedures used to induce cerebral focal ischemia: suture (n = 18) and three-vessel ligation (TVL: n = 13) groups. Both relative spin density and T1 were extracted from the acquired MR images. After correcting for radiofrequency field inhomogeneities, T2* signal decay, and temperature effects, in vivo regional brain water content, in absolute terms, was obtained by normalizing the measured relative brain spin density of animals to that of a water phantom. A highly linear relationship between MR-estimated brain water content based on the normalized spin density and wet/dry measurements was obtained with slopes of 0.989 and 0.986 for the suture (r = 0.79) and TVL (r = 0.83) groups, respectively. Except for the normal subcortex of the TVL group (P < 0.02) and the normal hemisphere of the suture group (P < 0.003), no significant differences were observed between MR-estimated and wet/dry measurements of brain water content. In addition, a highly linear relationship between MR-measured R1 (= 1/T1) and 1/W of wet/dry measurements was obtained. However, slopes of the linear regression lines in the two groups were significantly different (P < 0.02), indicating that different R1 values were associated with the same water content depending on the model. These results show that an absolute measurement of in vivo regional brain water content can be obtained with MRI and potentially serves as a noninvasive means to monitor different therapeutic interventions for the management of brain edema subsequent to stroke and head trauma. (+info)
In vivo analysis of dynamic tensile stresses at arterial end-to-end anastomoses. Influence of suture-line and graft on anastomotic biomechanics.
(10/573)
OBJECTIVE: to determine the influence of an anastomotic suture line and a graft on dynamic tensile stresses of vascular end-to-end anastomoses in vivo. MATERIAL AND METHODS: the abdominal aorta of twelve 35-kg pigs was used as an experimental model. Simultaneous recordings of internal arterial diameter and pressure were performed on each pig at 3 successive stages: (1) The genuine artery (REF), (2) artery-artery (A-A) and (3) graft-artery (G-A) anastomosis at 1-mm increments in the immediate perianastomotic area. Thereby, RD (relative distension), CC (compliance coefficient), E(p)(dynamic pressure-strain elastic modulus) and hysteresis loop areas could be calculated for every measuring point. RESULTS: the graft was significantly stiffer than REF. A-A and G-A anastomoses were significantly less compliant than REF. Maximum E(p), minimum CC and hysteresis loop areas were found at the anastomotic line due to minimum anastomotic RD. Downstream of the G-A anastomosis, the RD, CC, E(p)and loop areas were significantly different from REF, but significantly different from A-A. CONCLUSION: an animal model for acute studies of mechanical properties of vascular end-to-end anastomoses was developed. The main determinant for anastomotic biomechanics was the suture-line itself. (+info)
The search for an ideal method of abdominal fascial closure: a meta-analysis.
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BACKGROUND AND OBJECTIVE: The ideal suture for abdominal fascial closure has yet to be determined. Surgical practice continues to rely largely on tradition rather than high-quality level I evidence. The authors conducted a systematic review and meta-analysis of randomized controlled trials to determine which suture material and technique reduces the odds of incisional hernia. METHODS: MEDLINE and Cochrane Library databases were searched for articles in English published from 1966 to 1998 using the keywords "suture", "abdomen/surgery", and "randomized controlled trials". Randomized controlled trials, trials of adult patients, and trials with a Jadad Quality Score of more than 3, comparing suture materials, technique, or both, were included. Two independent reviewers critically appraised study quality and extracted data. The reviewers were masked to the study site, authors, journal, and date to minimize bias. The primary outcome was postoperative incisional hernia. Secondary outcomes included wound dehiscence, infection, wound pain, and suture sinus formation. RESULTS: The occurrence of incisional hernia was significantly lower when nonabsorbable sutures were used. Suture technique favored nonabsorbable continuous closure. Suture sinuses and wound pain were significantly lower when absorbable sutures were used. There were no differences in the incidence of wound dehiscence or wound infection with respect to suture material or method of closure. Subgroup analyses of individual sutures showed no significant difference in incisional hernia rates between polydioxanone and polypropylene. Polyglactin showed an increased wound failure rate. CONCLUSIONS: Abdominal fascial closure with a continuous nonabsorbable suture had a significantly lower rate of incisional hernia. The ideal suture is nonabsorbable, and the ideal technique is continuous. (+info)
Using tissue adhesive for wound repair: a practical guide to dermabond.
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Dermabond is a cyanoacrylate tissue adhesive that forms a strong bond across apposed wound edges, allowing normal healing to occur below. It is marketed to replace sutures that are 5-0 or smaller in diameter for incisional or laceration repair. This adhesive has been shown to save time during wound repair, to provide a flexible water-resistant protective coating and to eliminate the need for suture removal. The long-term cosmetic outcome with Dermabond is comparable to that of traditional methods of repair. Best suited for small, superficial lacerations, it may also be used with confidence on larger wounds where subcutaneous sutures are needed. This adhesive is relatively easy to use following appropriate wound preparation. Patients, especially children, readily accept the idea of being "glued" over traditional methods of repair. (+info)
Peripheral vascular anastomotic aneurysms: a fifteen-year experience.
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A 15-year experience with anastomotic aneurysms resulting from peripheral vascular reconstruction is presented. The analysis is divided into three 5-year periods. It is obvious from this presentation that the etiology is probably caused by suture material, end-to-side anastomosis, proximity of the anastomosis to a joint and intimectomy of the recipient artery at the original operative procedure. None of the lesions reported herein were associated with graft or wound sepsis. Anastomotic aneurysms at the proximal aortic suture line resulted in aortoenteric fistulae in 6 of 8 cases. There were no survivors in these 6 cases despite successful graft replacement. It is to be emphasized that the complication of anastomotic aneurysm still remains a significant complication in peripheral vascular surgery with a 1.9% incidence noted in 320 operations performed from 1970-1974. (+info)
Effectiveness of the fold plication method in lung volume reduction surgery.
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OBJECT: The fold plication method is a new operative procedure for lung volume reduction surgery whereby the target area is obliterated by plicating the folded tissue using a knifeless stapler, without the use of bovine pericardium. The effectiveness of this new method was evaluated in patients with advanced pulmonary emphysema. PATIENTS AND METHODS: Two weeks before and 6 months after surgery, pulmonary function, static lung compliance, maximal esophageal pressure, maximal inspiratory and expiratory mouth pressures, 6-min walking distance and the Borg scale were determined in twenty consecutive patients who underwent video-assisted thoracoscopic unilateral surgery. RESULTS: There was an increase in forced expiratory volume in one second (31%), forced vital capacity, peak expiratory flow rate and maximal voluntary ventilation, and a decrease in functional residual capacity (-16%) measured by plethysmograph. Static lung compliance decreased, and maximal esophageal pressure, and maximal inspiratory and expiratory mouth pressures increased. The 6-min walking distance increased (20%) and the Borg scale decreased (5.9 to 3.5). CONCLUSION: The results compare favorably with those obtained with other methods. Thus, the fold plication method could be considered an alternative procedure for lung volume reduction surgery. (+info)
Early experience with infectious complications of percutaneous femoral artery closure devices.
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Percutaneous femoral artery closure devices are being used routinely after cardiac catheterizations. The use of these devices has been advocated to decrease length of stay, promote early ambulation, and prevent bleeding. We reviewed the use of these devices in our institution and report three cases of infectious complications (two pseudoaneurysms and one infected hematoma). Reports of infected pseudoaneurysms after cardiac catheterization before the implementation of these devices are rare. The use of these devices may be associated with an increased incidence of infected femoral pseudo-aneurysms. (+info)
Episiotomy repair: Vicryl versus Vicryl rapide.
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Women suffer a significant degree of perineal morbidity in the postpartum period. For some, it can be significant and interfere with daily activities. Although there seems to be no doubt that polyglycolic acid derivatives are superior to non absorbable sutures with regard to wound healing, problems still occur with their use. In this study a relatively new product, Vicryl rapide, was compared with Vicryl. (+info)