Biomedical subjects

K C Shestak

Publications and source records attributed to K C Shestak.

29 records · Page 2Linked to original sources

PubMed1992

Microvascular free tissue transfer for reconstruction of head and neck cancer defects.

Over the last 10 years, microvascular free tissue transfer techniques have broadened the range of the head and neck surgeon, allowing for successful reconstruction of extensive curative extirpations in one operation with minimal morbidity. Success rates of more than 90% are now being achieved consistently. This article provides an overview of these revolutionary techniques for oral cavity, mandibular, and hypopharyngeal reconstructions. Patients are selected for microvascular free tissue transfer because of the large size of their defect, its location (eg, anterior mandibular loss), or complexity (circumferential defects of the hypopharynx). Others may be good candidates for this surgery because of previous radiotherapy or failed reconstructive surgery. Donor sites range from the radial forearm to the jejunum.

Follow-Up Studies↗

PubMed1991

Extremity replantation.

Although the success of replantation and revascularization is in part related to the length of the ischemic interval, it is important to bear in mind that microsurgical intervention must be given appropriate priority relative to the patient's other injuries. Very few patients die as a result of upper extremity trauma. However, the economic, psychologic, and physical debility of a chronic hand injury will be the ultimate handicap in patients who survive multisystem trauma. Therefore, management of the injured extremity has an important place in the overall scheme of trauma care.

Amputation, Traumatic↗

PubMed1991

Revascularization of an ischemic limb by use of a muscle pedicle flap: a rabbit model.

A rabbit model of hind limb ischemia was designed to demonstrate that new, hemodynamically significant arterial connections will develop between ischemic skeletal muscle and an independently perfused muscle pedicle flap. The right common iliac artery was divided in 15 rabbits. In eight rabbits a muscle flap based on the left deep inferior epigastric artery was transposed to the right thigh (flap group). In seven rabbits a sham operation was performed where the flap was sutured to the abdominal wall (sham group). After 7 days angiography demonstrated arterial connections between the flap and the native limb circulation in all of the flap group animals. The flap increased muscle perfusion in the ischemic limb (2.99 ml/100 gm muscle/minute in the flap group, vs 2.06 ml/100 gm muscle/minute in the sham group, p less than 0.005). Hemodynamically significant vascular connections will develop between a well-perfused muscle flap and an ischemic limb. The augmentation in perfusion provided by these connections can be quantified.

Animals↗

PubMed1991

Microsurgical free-tissue transfer in the elderly patient.

During the 5-year period from July of 1984 to July of 1989, we performed 94 free-tissue transfers in 92 patients over the age of 50 whom we arbitrarily defined as "elderly." There were 32 patients in the age range between 50 and 59 years, 40 patients aged between 60 and 69 years, and 20 patients aged between 70 and 79 years. Seventy-one flaps were utilized for head and neck reconstruction, and 23 flaps were used in reconstruction of the trunk and extremities. There was 1 total flap loss, for a flap viability rate of 99 percent (93 of 94). Postoperative complications were classified into surgical (technical) and medical categories. There were 14 major surgical complications (15 percent) and 13 significant postoperative medical problems (14 percent). The majority of these complications occurred in head and neck cancer patients in the age group between 60 and 69 years, who had significant underlying medical problems and were preoperatively classified as ASA 3. There were 5 postoperative deaths, for a mortality rate of 5.4 percent (5 of 92 patients).

Age Factors↗

PubMed1990

A model of persistent partial hindlimb ischemia in the rabbit.

An animal model of resting limb ischemia in the rabbit was developed and studied. Anesthetized rabbits underwent unilateral common iliac artery (CIA) division, allowing comparisons between an experimental (ischemic) and the contralateral control limb in the same animal. The time course and severity of the ischemic insult were measured by quantitating muscle blood flow in seven muscle groups using 57Co-radiolabeled microspheres, limb femoral arteriovenous oxygen differences (AVDO2), and limb arterial pressure. Nine of 20 animals had objective evidence of functional limb impairment judged by abnormal resting posture and/or abnormal gait. Muscle blood flow in the experimental limbs became significantly less than blood flows of corresponding contralateral muscle groups (P less than 0.05) when measured at 1 week after CIA division. By 17 days, mean muscle blood flow had returned to within 82.5% of that of the control limb. AVDO2 increased from 4.8 +/- 0.99 to 8.13 +/- 2.26 ml O2/dl blood following CIA division and remained persistently greater than the control limb value until Day 31. Limb arterial pressure decreased markedly after CIA division and remained significantly depressed beyond 6 weeks when the study was terminated. The reasons for the differential time courses of these parameters of blood flow are discussed. Common iliac artery division in the rabbit appears to produce persistent, partial ischemia at least 17 days in duration, allowing in-depth study of the effects of persistent limb ischemia on muscle cell function in the laboratory setting, as well as permitting the assessment of various therapeutic manipulations for the treatment of prolonged muscle ischemia.

Animals↗

PubMed1990

Indirect revascularization of the lower extremity by means of microvascular free-muscle flap--a preliminary report.

We describe the treatment of a patient with end-stage peripheral vascular disease and ischemic ulceration of the lower extremity in whom an obliteration of the distal arterial bed precluded conventional arterial reconstruction. A nonhealing dorsal foot ulcer was debrided, and soft tissue reconstruction was accomplished by the free microsurgical transfer of a muscle flap to the distal lower extremity. Arterial inflow to this free flap was provided by a contralateral reversed saphenous vein graft from the proximal arterial tree of the leg. This procedure resulted in a healed wound, stable coverage, and limb salvage. The patient also noted complete relief of rest pain and improvement in his claudication symptoms. A follow-up arteriogram was done 2 months after surgery. Contrast injection directly into the artery of this flap showed new blood vessel growth from the muscle flap into the foot with anastomoses of these "new vessels" to the patient's native circulation. This experience suggests that limb salvage may be possible by the free microvascular transplantation of a muscle flap onto the limb in selected patients whose limbs are deemed "nonreconstructible."

Angiography↗

PubMed1990

Expanding the horizons in treatment of severe peripheral vascular disease using microsurgical techniques.

The use of microvascular tissue transfer as an adjunct to arterial reconstruction has begun to have a positive impact on limb salvage in patients with advanced arteriosclerosis and nonhealing ischemic wounds. However, many patients with severe peripheral vascular insufficiency not amenable to conventional arterial reconstructive procedures eventually require limb amputation. We have treated 12 patients with advanced peripheral vascular disease and nonhealing ischemic wounds by three different methods. These included distal bypass alone, distal bypass done in conjunction with free-tissue transfer, and free-tissue transfer alone. All bypass grafts were done to vessels at or below the ankle using a reversed saphenous vein. In each case, the distal anastomosis was performed, using the operating microscope and standard microvascular technique. Mean follow-up for these patients is 18 months. Distal bypass alone resulted in limb salvage in three of five patients. In the combined bypass and free-flap group, three of five patients had salvage of their threatened extremity at a 1-year follow-up. Two patients with ischemic ulcers, rest pain, and unsuitable distal vessels for bypass were treated with free-tissue transfer alone. This resulted in healed wounds, limb salvage, and complete resolution of the rest pain symptoms in both patients. When advanced ischemia is complicated by large areas of tissue loss, combined bypass and microvascular free-issue transfer, performed in stages or simultaneously, is safe and can often result in limb salvage. In the rare instance of a completely obliterated distal runoff bed, free-tissue transfer alone may provide not only a healed wound, but also a means of "indirect" revascularization of the extremity and limb salvage.

Aged↗

PubMed1988

Immediate microvascular reconstruction of combined palatal and midfacial defects using soft tissue only.

Maxillary and midface defects with or without orbital involvement are disfiguring and disabling problems especially in the elderly cancer patient. Often, palatal prostheses are required to enable speech and swallowing. Elderly patients or those with compromised vision often find these appliances cumbersome and difficult to manage. To help obviate these problems a one-stage method of immediate palatal reconstruction was needed to obturate the palate and restore facial contour. Over the past 18 months six patients have undergone immediate reconstruction of complex, composite defects of the maxillary and midface structures after tumor extirpation, three of which extended into the orbit. The latissimus dorsi musculocutaneous flap was utilized because of its bulk, reliable anatomy, ample pedicle length and diameter, and minimal donor site morbidity. No flap loss, suture line dehiscence, or infection occurred. All patients were capable of deglutition and intelligible speech. This technique is a one-stage reconstruction of the palate and accompanying defects of the midface and maxilla that obviates the need for cumbersome palatal appliances.

Carcinoma, Squamous Cell↗

PubMed1988

Immediate microvascular reconstruction of combined palatal and midfacial defects.

We describe a method for immediate one-stage reconstruction of combined palatal and midfacial defects using latissimus dorsi musculocutaneous free-tissue transfer. It has consistently provided healed wounds, restoration of palatal function, and preservation of facial contour while obviating the need for a palatal prosthesis. This reconstructive method, which uses only autogenous tissue, may offer a significant advantage in cases where more than a hemimaxillectomy is required, for compound defects resulting from the sacrifice of facial structures along with the maxillectomy, and in situations where the resection involves cranial base structures with a resultant need to separate the cranial contents from the oral and nasal cavities. Finally, it provides an alternative to prosthetic rehabilitation for the elderly patient with decreased or absent vision.

Facial Neoplasms↗

PubMedDate not supplied

Effect of advanced age and medical disease on the outcome of microvascular reconstruction for head and neck defects.

During the 5-year period from July 1984 to 1988, 72 patients over the age of 50 underwent microvascular free tissue transfers for head and neck reconstruction. There were 22 patients aged 50-59 years, 31 patients aged 60-69 years, and 19 patients aged 70-79 years. Seventy of these procedures (97%) were done at the time of ablative surgery utilizing a two-team approach. There was 1 total flap loss for a flap viability rate of 99% (73/74). There were 46 complications in 40 patients: 21 surgical and 25 medical. Twelve of the surgical complications required reoperation for a major surgical complication rate of 16%. Major medical complications developed in 12 patients (16%). Medical complications more commonly were observed in patients aged 60-69 years who had significant preoperative comorbidity and were classified as ASA class 3 or greater. There were 5 postoperative deaths for a mortality rate of 7%. Advanced chronologic age does not compromise the technical success of microsurgical free tissue transfer in the elderly patient with head and neck cancer. The risk of medical complications is significant and is directly related to concurrent illness of the individual patient rather than to age alone.

Age Factors↗

PubMedDate not supplied

Vascularized free-tissue transfer in head and neck surgery.

Microsurgical vascularized free-tissue transfer has had a dramatic impact on the field of head and neck reconstruction. This technique has extended the extirpative limits of resection by facilitating complex reconstruction of head and neck defects in one stage with very high success and minimal patient morbidity. Although its impact on improving cure rates and survival statistics has yet to be determined, it has proven very valuable in the palliation of patients with advanced malignancies. The horizons for future applications are infinite. Neurotization of free-flap transfer may potentially improve the functional outcome for patients. In the future, free flaps may be prefabricated to allow for improved mandibular reconstruction or tracheal reconstruction. These tissue composites may potentially be a vehicle through which adjuvant therapy can be better delivered to the tumor bed. Microsurgical free-tissue transfer will have an expanding role in the treatment of patients with head and neck tumors, and continued refinements in these techniques will open new vistas for the reconstructive surgeons in the future.

Face↗