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At least 199 records · Page 11Linked to original sources

Microsurgery of cerebral lesions under stereotactic conditions.

Microsurgical excision of cerebral lesions was carried out under CT-guided stereotactic conditions. For lesions located in critical cortical areas, cerebral teleangiography under stereotactic conditions provided the coordinates of the vascular elements related to the structures and adjacent to the lesion without X-ray distortion. Small size cortical and subcortical lesions were targeted using the stereotactic biopsy probe as a guide. In twenty-four patients stereotactic microsurgery was used for following lesions: 8 cavernomas, 8 metastases, 7 gliomas, and 1 tuberculoma. Unpredictable permanent neurological complications did not occur, but predicted transient impairment after surgery in functional territories was tolerated with the complete removal of the lesion. The advantages of microsurgery using stereotactic coordinates are: precise knowledge of the location of brain structures and exact targeting of intracerebral lesions, better evaluation of surgical risks, easy spatial orientation, and minimization of the surgical damage to the healthy brain tissue.

Adolescent↗

A comparison of glyceryl trinitrate and labetalol as hypotensive agents in microsurgery of the middle ear.

Ninety-five patients undergoing microsurgery of the middle ear were anaesthetised using thiopentone, nitrous oxide, oxygen and halothane via a low flow circle system, with carbon-dioxide absorption. Systolic blood pressure was reduced to approximately 65 mmHg either by the use of increments of labetalol, or by an infusion of glyceryl trinitrate (GTN). The degree of haemostasis achieved was assessed by the surgeon who was unaware which hypotensive agent was being used. Both hypotensive agents produced good conditions in all patients. Thus GTN is a suitable agent to induce hypotension for this type of microsurgery.

Adolescent↗

Another method to prevent venous thrombosis in microsurgery: an in situ venous catheter.

Free-flap failure is in the order of 4 to 10 percent. Heparin is more effective at preventing venous thrombosis than arterial thrombosis. This study was undertaken to investigate the efficacy of delivering heparin at a high dose locally but low dose systemically (heparin infusion via a catheter placed proximal to the venous anastomosis) to prevent venous thrombosis in microsurgery. A model of venous thrombosis was first established by a venous inversion graft in the rat femoral vein (this was performed in seven animals and resulted in 100 percent thrombosis). Saline and heparin were delivered proximal to the inverted vein graft to assess the effect of each in preventing venous thrombosis. Flow/patency distal to the inverted vein graft was assessed by observation under the microscope, the milk test, and rate of flow (flowmeter). Saline infused via a catheter proximal to the venous inversion graft resulted in 100 percent thrombosis in 10 animals. Heparin (100 U/ml at 2 to 3 ml/hour) infused through a catheter for 2 hours proximal to the anastomosis resulted in flow in all 10 animals during the infusion. Blood was also taken before beginning the procedure (control) and after the heparin infusion distal to the anastomosis (local partial thromboplastin time) as well as in the contralateral femoral vein (systemic). The control for all animals that received heparin was <3 minutes. The systemic partial thromboplastin time after heparin infusion was <3 minutes in seven animals, 3.3 minutes in two animals, and >7 minutes in one animal. The local partial thromboplastin time distal to the inverted vein graft was >10 minutes in nine animals and 3.7 minutes in one animal. The study also had a clinical component, in which a catheter was placed in a vein of the free flap, and heparin was infused over 5 days. This technique has been used in 83 consecutive free flaps. In three recent free flaps performed on the limbs, the local partial thromboplastin time (close to the anastomosis) was raised but the systemic time was normal. This technique offers a method in preventing venous thrombosis in microsurgery. It is simple to implement and is not associated with the systemic complications of heparin.

Adult↗

Impact of re-resection for inadequate margins on the prognosis of upper aerodigestive tract cancer treated by laser microsurgery.

OBJECTIVES: Positive or uncertain surgical margins left untreated have a distinct prognostic relevance in squamous cell carcinoma of the upper aerodigestive tract. An advantage of transoral laser microsurgery is that it can be easily repeated if inadequate resection margins are found postoperatively. The present study investigates the impact of laser surgical reresection on the outcome of patients. STUDY DESIGN: The authors conducted a retrospective unicenter study. METHODS: A review of 1,467 patients with squamous cell carcinoma of the upper aerodigestive tract who were initially treated by transoral laser microsurgery with curative intent between August 1986 and December 2002 was conducted. Locoregional control as well as TNM adjusted and overall survival were analyzed using the Kaplan-Meier method. RESULTS: Three hundred eighty-six patients have required reresection to obtain clear surgical margins, in 70 of whom residual carcinoma has been detected in revision specimens. Patients without need for revision and those in whom revision specimens were found tumor-free had an almost identical locoregional control (P = .4611). In patients with positive revision specimens, however, locoregional control was significantly worsened (P = .0058). Neither the need for reresection nor the detection of further tumor tissue in revision specimens affected TNM adjusted or overall survival. CONCLUSIONS: Survival of patients was similar whether clear resection margins were reached within the first surgical step or with revision surgery. However, patients in whom reresection specimens contained residual carcinoma had an increased risk of locoregional failure and should undergo a further reresection or at least a very close follow up.

Adolescent↗

Use of distally pedicled sural fasciocutaneous cross-leg flap in severe foot and ankle trauma: a safe alternative to microsurgery in very young children.

Advances in reconstructive microsurgery have enabled us to make use of many flap alternatives in severe lower-extremity trauma, and traditional cross-leg flaps for wound coverage have been replaced in most centers by free-tissue transfers. But free-flap surgery is still a challenging area in very young pediatric populations because of technical difficulties with considerable drawbacks. Six children with severe foot and ankle trauma were presented. Distally based sural fasciocutaneous cross-leg flaps were carried out to cover the defects, with no complications. Because of its easy dissection and reliable pedicle without compromising the major vessels, this procedure may be a safe choice among the other cross-leg flap alternatives when microsurgery is not considered.

Ankle Injuries↗

Indocyanine-green fluorescence video angiography used clinically to evaluate tissue perfusion in microsurgery.

BACKGROUND: Laser-induced fluorescence angiography with indocyanine-green (ICG-FA) is a new diagnostic approach that allows quantitative evaluation of tissue perfusion in microsurgery as well as an analysis of the uptake, distribution, and clearance of dye-marked blood. METHODS: The ICG-FA technique was evaluated for its sensitivity and prognostic value in comparison with clinical parameters (turgor, temperature, reperfusion time, bleeding after puncture) during and after different surgical procedures. Altogether, 91 measurements were made in cases of microvascular repair (n = 43) and free-flap surgery (n = 48). RESULTS: Because of discrepancies between ICG-FA results and clinical findings, the planned postoperative management was changed 43 times (47.2%). In cases of microvascular repair that subsequently resulted in tissue necrosis, ICG fluorescence had a significantly higher prognostic value than any of the clinical parameters (p = 0.03). During free-flap surgery, intraoperative ICG-FA had better sensitivity for flap loss than clinical parameters, but postoperative ICG-FA did not. CONCLUSIONS: Fluorescence angiography with ICG is a sensitive diagnostic tool for detecting compromised tissue perfusion in trauma surgery and microsurgery. Its use may improve perioperative management and thereby lead to better clinical results.

Adolescent↗

Transsphenoidal microsurgery for Cushing's disease.

Nineteen patients thought to have Cushing's disease were treated by transsphenoidal microsurgery; the type of operation performed depended upon the findings in the individual patient. Seventeen patients remitted. Failures occurred in a patient with an invasive macroadenoma and in a patient who was subsequently found to have a thymic carcinoid tumour secreting ACTH. One patient who remitted suffered a recurrence during pregnancy, 30 months after operation. The ten patients (Group I) who had a selective removal of a microadenoma or a limited resection of the gland were often GH deficient, but seven regained cortisol reserve and all ten regained normal pituitary-thyroid and pituitary-gonadal responses. By contrast abnormalities of pituitary function were common in nine patients who had a radical or total hypophysectomy. We conclude that transsphenoidal microsurgery is the best treatment for Cushing's disease and that, when feasible, a selective microadenomectomy is the most appropriate operation.

Adenoma↗

Indications for the treatment of tubal infertility patients by microsurgery or in vitro fertilization.

Pregnancy rates following the treatment of tubal infertility patients by microsurgery or in vitro fertilization (IVF) have been analysed. The results indicate that microsurgery should be the primary treatment for the following: (a) Sterilization reversal (except fimbriectomies or tubes of less than 3cm length); (b) Incomplete lateral tubal occlusion; (c) Medial tubal occlusion; (d) Peritubal or periovarian adhesions. IVF is indicated as the primary treatment for tubal infertility patients when investigation demonstrates (a) Total lateral tubal occlusion; (b) Previous fimbriectomy sterilizations; (c) Reconstructable tubal length of less than 3cm.

Female↗

Endoscope-assisted microsurgery for treatment of a suprasellar craniopharyngioma presenting precocious puberty.

Being the most common childhood tumor to involve the hypothalamus and pituitary gland, craniopharyngioma, a histologically benign tumor, is usually related to growth retardation and hypogonadism. The presentation of precocious puberty is very rare for a hypothalamic craniopharyngioma. Here, we report such a case. The female patient had presented with symptoms of menarche and breast development since she was 6 years old. Hormonal therapy with a gonadotropin-releasing hormone analogue was instituted to cease precocious puberty but was unsuccessful. Magnetic resonance imaging of the sella showed a 1-cm tumor in the hypothalamic area. Through a pterional approach, the tumor was removed en bloc with endoscope-assisted microsurgery. After the operation, our patient's symptoms improved, so the hormone therapy was discontinued. This extremely unique association of craniopharyngioma and precocious puberty, the causes and mechanisms involved along with the advantages of endoscope-assisted microsurgery are discussed.

Child↗

Brain tumors with cysts treated with Gamma Knife radiosurgery: is microsurgery indicated?

Cysts, which are not uncommonly associated with brain tumors, may be responsible for neurological dysfunction. Stereotactic aspiration of such lesions can lead to clinical improvement, but cyst recurrence is common and multiple aspirations may be necessary. Thirteen cases of brain tumors with cystic components were treated by radiosurgery with follow-up of 5-29 months (median 14 months). The tumor diagnoses were three cystic craniopharyngiomas, two brain stem cystic astrocytomas, two cystic cerebellar astrocytomas, one cerebellar hemangioblastoma, one ganglioglioma, one fourth ventricle tumor, one cerebellopontine angle pilocytic astrocytoma, one metastasis from lung cancer and one glioblastoma. The dose at the tumor margin ranged between 10 and 20.5 Gy (mean 15.5 Gy) and the maximum dose ranged between 18 and 45 Gy (mean 32.3 Gy). In 11 of these cases the cystic component recurred in spite of a decrease in the size of the solid tumor component. An Ommaya reservoir was inserted in six cases, stereotactic aspiration was performed in two cases, microsurgery was undertaken in two cases after 2-8 months (mean 4.8 months) and one patient refused further treatment. Multiple aspirations through the Ommaya reservoir were performed in the outpatients on the two patients who required them. It may be appropriate to be cautious in advising radiosurgery for intracranial tumors with a significant cystic component. Microsurgery if possible may be preferable in this situation.

Adolescent↗

Transsphenoidal microsurgery for newly diagnosed acromegaly: a personal view after more than 1,000 operations.

The aim of this short review is to inform about the possibilities and limits of transnasal microsurgery in acromegaly. The current reports on surgical remissions, according to the strict criteria with international consensus using age- and sex-related normal levels for insulin-like growth factor-I and suppression of growth hormone (GH) with oral glucose tolerance below 1 mug/l, are more or less agreeable with values between 34 and 74%. In microadenomas (<10 mm in diameter), 59-95% remissions are published. Some improvement might be achieved in macroadenomas which presently have a chance of 26-68% to be satisfactorily operated on. Special instruments introduced by us to visualize and remove partially invasive adenoma parts are described. Intraoperative magnetic resonance imaging is discussed. With intraoperative measurement of GH, small adenoma rests <3 mm can be diagnosed. When GH did not sufficiently decline, an additional tumor search resulted in a significant improvement in results in resectable macroadenomas. With these techniques, we achieved remission rates which can hardly be further increased (micros 95%, macros 68%). In grossly invasive grade 4 adenomas, which are frequent in our unit, only an 80-95% reduction in tumor mass is feasible. Preoperative treatment with somatostatin analogues as used in most of our patients reduces the comorbidity and facilitates adenoma removal which is still controversially discussed in the literature. The complication rate of microsurgery in experienced hands is low.

Acromegaly↗

Microsurgery for Brescia-Cimino fistula construction in pediatric patients.

Many previous series reporting the construction of Brescia-Cimino fistulae in children describe a high rate of immediate and late patency failure. Using microsurgery, we have constructed 23 Brescia-Cimino fistulae in 23 children, 10 weighing less than 20 kg and 13 weighing more than 20 kg. An immediate patency rate of 100% was achieved in both weight groups with a late patency rate of 90%-100%, in those under and over 20 kg, respectively. We recommend using microsurgery for all such angioaccess procedures.

Adolescent↗

Recombinant hirudin--initial observations in reconstructive microsurgery.

Recent advances in microvascular techniques have significantly enhanced the success rate of these procedures. Microvascular free tissue transfers at present have a 85-90% success rate. This, however, still leaves a 10-15% failure rate due primarily to thrombosis of the blood vessels at the anastomotic site. Previous work in the field has shown that anticoagulants such as heparin can reduce the rate of thrombosis. However, heparin can also cause on-site bleeding. Hirudin, a potent thrombin inhibitor of 65 amino acids, is available through recombinant technology. Our current experimental work utilized 75 male Sprague-Dawley rats for assessing the efficacy of hirudinized saline versus saline alone and heparinized saline as an irrigant in a microsurgery model of anastomosis. After exposing the right femoral artery in a standard fashion, the artery was clamped and a standard transverse division of the vessel was made. The vessel ends were irrigated with one of the three solutions then anastomosed. Vessels were observed for patency over a 3-day period. Initial results showed comparable performance of hirudinized saline and heparized saline, both of which were better than saline, for preventing thrombosis. From these initial data, and the reduced bleeding risk associated with hirudin, this agent appears to be a useful anticoagulant in microsurgery.

Anastomosis, Surgical↗

Vascular microsurgery in the ex situ kidney. An experimental study.

Work in vascular microsurgery is presented. We previously studied the vascular network and the pyelocaliceal system in the dog by means of moulding. Vascular microsurgery was practised on small animals. Operative protocol on the kidney was performed ex situ in 15 dogs. Our results with arteriographic and pathological control are presented.

Animals↗

Transsphenoidal microsurgery in the treatment of acromegaly and gigantism.

Twenty-five patients with acromegaly and 3 patients with gigantism underwent transsphenoidal microsurgery in an attempt to remove the tumor and preserve normal pituitary function whenever possible. An adenoma was identified and removed in 27 of 28 patients. Evaluation 3--6 months postoperatively revealed a GH level less than 5 ng/ml in 29 patients, 5--10 ng/ml in 4 patients and 11--29 ng/ml in 4 other patients. Dynamics of GH secretion were normal in 11 patients who had normal pituitary function and are considered cured. Two patients with low or undetectable GH levels are also considered cured at the expense of being hypopituitary. Three of 7 patients with normal basal GH levels but abnormal dynamics of GH secretion relapsed within 1 yr. Eleven of the 13 patients considered cured did not have extrasellar extension, while 14 of the 15 patients not cured had extrasellar extension. Five patients who were not cured with surgery received radiation therapy. Three patients were treated with an ergot derivative, Lergotrile mesylate, after surgery and radiation therapy failed to normalize GH levels. Transsphenoidal microsurgery is an optimal form of therapy for patients with acromegaly or gigantism, especially those with no extrasellar extension. Dynamics of GH secretion are very useful in evaluating the completeness of adenoma removal.

Acromegaly↗

Laryngeal microsurgery under general anesthesia using small-bore endotracheal tubes: blood gas analysis.

This study reports variations observed under general anesthesia through small-bore endotracheal tubes in PO2, PCO2, HCO3, percentage saturation of O2, and pH levels in 39 patients who underwent laryngeal microsurgery lasting from 10 to 100 minutes. The tendency to an increase in PCO2 levels reached statistical significance only at the 100th minute but did not constitute a risk for patients as values remained within the limits of "permitted hypercapnia." PO2, percentage saturation of oxygen, and HCO3 levels did not vary significantly. pH values tended to fall (respiratory acidosis) in correlation to the increase in PCO2. Small-bore endotracheal tubes can safely be used for laryngeal microsurgery when operating times are not longer than 100 minutes.

Anesthesia, General↗

Carbon dioxide laser microsurgery for tongue cancer: surgical techniques and long-term results.

Thirty-seven consecutive patients with cancer of the anterior two-thirds of the tongue without clinical neck lymph nodes or distant metastasis were treated with transoral carbon dioxide (CO2) laser microsurgery. During the operation, a monopolar coagulation-suction device was applied to achieve a clear surgical field. Under a surgical microscope, we repeatedly palpated the soft tissue to identify the tumour margins, in particular the deep margin, to maintain adequate safe margins in three dimensions. We resected the tumour by en bloc procedures rather than by vaporization or debulking. Of the 28 patients in the T1 and T2 groups, 26 patients did not receive postoperative radiotherapy. The local control rate calculated by the methods of Kaplan and Meier in all 37 patients at 5 years was 93.6%. No local recurrence occurred in the T1 or T2 cases. Nine patients suffered from neck recurrence and the neck control rate at 5 years was 74.6%. Eight of these nine patients were salvaged by surgery with adjuvant radiotherapy, and six of them finally achieved disease-free status. The 5-year disease-free survival rate for our series was 88%. Our surgical techniques using CO2 laser microsurgery are effective and advantageous methods for excision of oral tongue cancer, especially stage I and II lesions.

Adult↗

Early glottic carcinoma (T1N0). Results of irradiation with or without endoscopic microsurgery.

Seventy-nine patients with T1N0 glottic carcinoma were treated at the Department of Radiology, University of Tokyo, between 1967 and 1977. The average total dose varied from 73 Gy in the first year to 32 Gy in the last year of the period. Endoscopic microsurgery was introduced in the middle of the period. The overall local recurrence rate was 15 per cent within 5 years. Observed and adjusted five-year survival rates were 79 and 91 per cent, respectively. Endoscopic microsurgery was not an important factor for local control rates and survival rates. Patients with T1N0 glottic carcinoma were successfully treated with a total dose equivalent to a time-dose-fractionation of 80 to 100.

Adult↗