摘要:

Treatment for recurrence after surgical removal of parotid benign pleomorphic adenoma (PBPA) has not been well defined and is often followed by further recurrence. Surgery is overwhelmingly the most common approach. The risk of facial nerve injury is greater at reoperation since the nerve is less well defined. The value of radiation therapy (RT) has not been determined and incurs with it the risk of possible late occurrence of malignancy or nerve damage. The charts of patients with recurrent PBPA treated consecutively by a single surgeon from 1965 to 1993 were reviewed. All patients had a histopathologically verified diagnosis of PBPA both at the time of primary and subsequent surgeries. Follow-up was obtained from clinical charts and correspondence communication. Recurrence curves were generated using the Kaplan-Meier method. Thirty-nine patients with recurrent PBPA (36 referred and 3 treated primarily at Mayo) were evaluated. The patients were classified according to the type of surgery: 14 patients had previously undergone some form of parotidectomy or had only resection of the tumor for recurrence, and 25 patients underwent parotidectomy since this had not been performed primarily. The mean age in the two groups was 49 and 50 years respectively. The mean follow-up was 10 years after the recurrence treatment. The mean time between initial resection and recurrence in the two groups was 14 and 15 years. The mean time between the recurrence treatment and a second recurrence was 7.5 years. Nine patients had RT in addition to the local resection. Of this group 3 patients (33%) developed another recurrence. Five patients had local resection only, and of this group 1 patient (20%) developed another recurrence. Of the group that had superficial parotidectomy, 3 patients had additional RT and one of these patients (33%) developed another recurrence. Twenty-two patients had superficial parotidectomy only, and of this group 3 patients (14%) developed another recurrence. Only 2 of the 39 patients had complications. One patient developed Frey's syndrome after superficial parotidectomy and 1 patient developed facial paralysis after RT. As in other series, the number of patients is inadequate to allow for firm conclusions. However, it appears that when previous parotidectomy has been performed, simple excision with a margin of surrounding tissue would seem appropriate. Parotidectomy should be carried out if not performed previously. In simple excision after previous parotidectomy, there is a greater risk to the facial nerve because of difficulty in distinguishing the facial nerve from surrounding scar tissue. Our preference is to use general anesthesia so that branches of the nerve are not paralyzed and stimulation of the nerve aids in safe dissection. The value of RT is still indeterminate.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Adventitia is usually removed from arteries to simplify microvascular anastomoses. Some surgeons peel the adventitia away bluntly whereas others trim the adventitia sharply with scissors. We used a rat cremaster flap for intravital microscopy to evaluate these two techniques. Animals with unmanipulated vessels, without anastomosis or adventitial removal, served as controls. Fifty-four rats were studied in three groups of 18 rats. Functional capillary density, red blood cell velocity, diameter of the flap's feeding artery (Al), microthrombi formation, and neutrophilic activity were studied for 5 hours following anastomosis, and 24 and 72 hours later. Histological changes in blunt and sharply prepared arteries were compared with control vessels. After blunt preparation, capillary perfusion was reduced to 61% of control values (p < 0.05) and Al diameter was reduced to 77% of control values (p < 0.05). Capillary perfusion and AI diameter were unchanged in sharply prepared arteries. Architectural changes in the vessel wall were more profound, and neutrophilic activity was increased in bluntly prepared arteries. In this study, sharp preparation of small arteries was beneficial compared with blunt preparation.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Thirty-one free vascularized fibular bone grafts were performed for treatment of osteonecrosis of the femoral head in 26 patients. Twenty-four men and 2 women ranged in age from 16 to 48 years (mean, 32 years). Twenty-one patients had unilateral disease. Five patients had bilateral disease and underwent staged bilateral free vascularized fibular grafts 3 months apart. Associated etiological factors included alcohol (9 patients), steroid use (7 patients), and trauma (1 patient). The condition was considered idiopathic in the remaining 9 patients. Radiological staging by Ficat included stage I in 1 hip, stage II in 15 hips, stage III in 14 hips, and stage IV in 1 hip. A skin island flap was used for monitoring purposes to check the patency of blood flow to the grafted fibula. One flap failed by venous occlusion and was left as a nonvascularized bone graft. Thirty hips were followed. Pain was relieved in 28 hips (93.3%) and aggravated in 2 hips (6.7%). On radiographic evaluation, 26 hips (86.7%) demonstrated excellent preservation of the femoral head contour. Progressive collapse of the femoral head (>1–2 mm) occurred in two hips, with 1-miri depression in one hip with stage III disease and 2-mm collapse in one hip with stage IV disease. Follow-up ranged from 12 to 40 months (mean, 21 months). In conclusion, even in this relatively short follow-up period, the free vascularized fibular bone graft is an excellent treatment modality for preserving the femoral head and relieving symptoms in patients with osteonecrosis of the femoral head.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We performed six immediate free flap reconstructions after tumor ablation in 5 children under the age of 15 years presenting with head and neck malignancy. One patient underwent free flap transfer on two separate occasions because of tumor recurrence. There were no flap losses nor were there any complications related to microvascular surgery. Although a pediatric head and neck malignant tumor is rare, surgical resection is the primary therapeutic role for those that are amenable to complete excision. Pediatric microsurgery provides a safe and reliable procedure for reconstruction of head and neck defects after extirpation of the tumor.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Reconstruction of the ala nasi and the alar base presents problems because of complex contours, skin color and texture, and limited availability of mobile, adjacent skin. A large percentage of basal cell carcinomas occur on the nose. When excised with adequate safety margins, these lesions create a defect too large for direct repair. This paper describes the use of the upper lip flap for reconstructing alar base defects and reconstructing the inner lining of the ala nasi in full-thickness defects of the ala nasi as an alternative to other procedures proved to be effective on this region. The base of the flap rests on the base of the columella. It is raised just over the underlying orbicularis oris muscle. The resulting donor defect is closed primarily. The outer aspect of defects of the ala nasi are covered with either a full-thickness skin graft, a forehead flap, or a cheek flap. The upper lip flap was used on 10 patients to reconstruct full-thickness defects of the ala nasi, for which an alar base needed to be reconstructed. The results were satisfactory in most patients. An upper lip flap can be used safely to reconstruct the ala nasi and alar base defects either alone or in combination with other flaps.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Skin flap ischemia has been associated with the presence of free radicals. In this study we designed a suture-induced delay model in 30 rats using two different suture techniques. A total of 13 rats that underwent McFarlane's acute random-flap model served as controls. We found a statistically significant difference between the flaps of the experimental and control groups regarding the viability of flaps. Malondialdehyde levels in tissue samples taken from the proximal and distal ends of each flap were estimated at 6 and 24 hours postoperatively. Malondialdehyde levels in the experimental groups were found to be quite lower than those of the controls. In conclusion, the suture-induced delay model seems to be effective in improving flap viability. Also, we found lower malondialdehyde levels in experimental groups compared with controls.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The effects of ischemia/reperfusion (I/R) injury in flow-through venous flaps were evaluated in rabbits. The rates of flap survival and the levels of lipid peroxidation, protein oxidation, and sulf-hydryl groups were compared between flow-through venous flaps, conventional flaps after an I/R period (experimental groups), and flow-through venous flaps without being subjected to I/R injury (control groups) in 20 animals. On the seventh day after the onset of reperfusion, 3 of 10 flow-through venous flaps (30%) and 6 of 10 arteriovenous flaps (60%) survived in the experimental groups. Flow-through venous flaps showed a decreased survival rate compared with control and conventional flaps (p < 0.05). Tissue lipid peroxide levels were found to be higher in venous flaps during reperfusion after secondary ischemia (p < 0.05). Tissue protein oxidation and total sulfhydryl groups levels did not show any difference among groups. This study suggests that more free radical damage occurs in flow-through venous flaps during I/R injury.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Ischemia/reperfusion injury (IRI) after free tissue transfer of the small intestine results in transmural tissue damage. This study examined the effects of IRI on the jejunum. Wistar rats served either as controls (N = 10) or underwent clamping of the infrarenal aorta for 1 hour followed by 1 hour of reperfusion (N = 10). Both ischemia and reperfusion reduced the protein and deoxyribonucleic acid content of the jejunal mucosa (p < 0.05). Myeloperoxidase activity in the jejunal mucosa remained relatively low. The expression of leukocyte function-associated antigen 1 and intercellular adhesion molecule 1 (ICAM-1) on the surface of mucosal cells was not altered significantly by the ischemic insult, but was reduced after the period of reperfusion (p < 0.05). This coincided with an increase in messenger ribonucleic acid (mRNA) for ICAM-1 within isolated mucosal cells (p < 0.05). The specific activity of glutaminase in isolated jejunal mucosal cells was diminished after ischemia and reperfusion (p < 0.05), and this was not associated with an appreciable change in glutaminase mRNA expression. These results have identified some molecular mechanisms underlying IRI of the small intestine that are possible candidates for therapeutic intervention.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The effect of hyperbaric oxygen (HBO) on ischemic muscle tissue pH was evaluated continuously. The hind limbs of male Sprague-Dawley rats (N = 11, both groups) were amputated and stored in room air (20.1% oxygen [O2], 1.0 ATM, 24°C) or in HBO (100% 02, 2.9 ATM, 24°C) for 240 minutes. Rat muscle tissue pH was continuously monitored with a micro-pH electrode following amputation. There was no significant difference between the average starting tissue pH of control and treated limbs (p = 0.45). At 240 minutes of ischemia the control group tissue pH decreased 0.80 pH units whereas the treatment group decreased 0.68 pH units (p < 0.05). The tissue pH of control limbs declined 30.7 times faster than treated limbs during the first 36 minutes of ischemia (p < 0.05). From 36 to 240 minutes the rates of acidosis were similar and did not differ significantly (p = 0.46). In a separate study, male Sprague-Dawley rats were anesthetized with pentobarbital and ketamine. Aortic arterial blood gases were obtained at 5 minutes (N = 8) and 15 minutes (N = 8) postanesthesia. The average serum pH, carbon dioxide, oxygen, and bicarbonate levels remained within normal limits in both groups and did not differ significantly (p > 0.05 for all parameters). Anesthesia produced no serum respiratory or metabolic acidosis and did not contribute to the initial ischemic tissue pH. These results suggest that HBO delays the progression of metabolic acidosis in this amputated limb model. This is further supporting evidence for the tissue-preserving effect of oxygen when delivered in hyperbaric conditions. However, the clinical application of this technique may be limited due to the difference in the volume of tissue presented for major limb replantation and the short window of beneficial effects.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

This study demonstrates that acute mainstream cigarette smoke exposure is deleterious to dorsal random-pattern skin flap survival in the rat. Three vasodilators were also studied for their ability to mediate flap survival after smoke exposure. Sprague-Dawley rats (10 per group) were exposed to two cigarettes per day over a 14-day period. This is an exposure equivalent to that of an average cigarette smoker. Dorsal McFarlane caudally based random-pattern skin flaps (4 x 10 cm) were created on day 7 of the smoke exposure. Enteral phenoxybenzamine (0.56 mg per kilogram per day), enteral nifedipine (10 mg per kilogram per day), and topical nitroglycerin (1.3 cm or 7.5 mg per day) were administered after creation of the dorsal skin flaps in two doses daily during smoke exposure. Fluorescein was used to delineate areas of viability accurately. A pad digitizer was utilized to calculate designated skin flap areas to ± 1.0 mm2. Experimental animals demonstrated a 23% decrease (p < 0.01) in skin flap area survival compared with the control animals. The phenoxybenzamine group demonstrated a 5.5% increase in flap area survival (p = 0.068), the nifedipine group demonstrated a 4.1% increase in flap area survival (p = 0.049), and the nitroglycerin group demonstrated an 8.9% increase in flap area survival (p = 0.049). These data suggest that phenoxybenzamine appears to affect skin flap survival marginally after smoke exposure. However, nifedipine and nitroglycerin improve random-pattern skin flap survival significantly after mainstream cigarette smoke exposure in the rat. These results imply that pharmacological intervention with vasodilators may ultimately prove clinically useful for random-pattern skin flap salvage in the cigarette-smoking patient.

ISSN:0148-7043    

出版商:OVID    

年代:1998

数据来源: OVID