Biomedical subjects

J Upton

Publications and source records attributed to J Upton.

At least 19 recordsLinked to original sources

PubMed1992

Hand reconstruction with allograft demineralized bone: twenty-six implants in twelve patients.

A long-term study of 26 phalangeal or metacarpal defects that were reconstructed with allogeneic demineralized bone implants demonstrates healing comparable to that which follows autogenous bone grafting. Average follow-up was 54 months. Five patients had multiple enchondromas (Ollier's syndrome), five children had congenital hand deformities, and all of these had previously had bone grafts harvested for associated craniofacial reconstructions. With the use of demineralized bone implants, tourniquet and operative times were significantly reduced and potential donor site morbidity was eliminated. Further, regional anesthesia was used more frequently and hospitalization time was reduced. There were no postoperative complications. Demineralized bone implants have been particularly useful in patients who previously had refused bone grafting.

Adolescent↗

PubMed1992

The use of scapular and parascapular flaps for cheek reconstruction.

This is a retrospective review of our experience with microvascular transfer of scapular and parascapular flaps for the correction of lateral facial contour deficiencies. Twenty-eight patients with congenital (n = 8) and acquired (n = 20) defects were treated with 30 flaps; two patients had bilateral flaps. The etiology of the defects included hemifacial microsomia (n = 2), oblique facial cleft (n = 1), Romberg's hemifacial atrophy (n = 5), neoplasm (n = 4), irradiation (n = 8), trauma (n = 4), tumor excision (n = 4), facial lipodystrophy (n = 2), and silicone granuloma (n = 2). The follow-up evaluation was from 2 to 13 years, with an average of 6 years. Fabrication of a facial moulage was part of the preoperative planning for each patient. These were compound flaps, including skin, deepithelialized skin, fat, fascia, and bone, if necessary. All flaps were constructed with an intact skin paddle for postoperative monitoring. Based on dissections and anatomic findings at operation, several variations in the level of emergence of the circumflex scapular artery from the triangular space and its branching patterns were noted. All flaps survived; changes in the patients' weights were reflected in the flaps. Twelve patients required secondary procedures: excision of skin monitor islands, scar revisions, debulking, or flap resuspension to the malar region. Bone grafts or alloplastic implants were necessary in four patients in whom the malar eminence could not be adequately corrected by transfer of a flap. The deepithelialized scapular/parascapular flap is preferred for correction of large lateral facial defects.

Adipose Tissue↗

PubMed1992

Principles of flap prefabrication.

Clinical flap prefabrication can be classified according to the basic technique of plastic surgery used for the prefabrication. There are currently three methods: (1) delay or expansion; (2) grafting; and (3) vascular induction by staged transfer. Illustrative cases are given to point out the advantages and indications for each method. A fourth, still experimental, method is based on cell biology advances that are looming on the horizon and may have revolutionary future clinical applications.

Adult↗

PubMed1992

Refinements in hand coverage with microvascular free flaps.

The specialized tissue requirements or dorsal and palmar skin are analyzed and options for full-thickness replacement outlined in detail. Thoughtful and accurate preoperative planning is the key to success. Dorsal coverage with a variety of pedicled and free fasciocutaneous flaps are quite satisfactory. Palmar coverage is more difficult and the need for sensation more critical. Free vascularized temporoparietal fascial flaps covered with full-thickness skin grafts are currently the treatment of choice for most complex wounds.

Aged↗

PubMed1991

The role of surgery in rhabdomyosarcoma of the head and neck in children.

The role of surgery in the treatment of rhabdomyosarcoma of the head and neck has diminished during the past 25 years. Treatment of this tumor in the pediatric population has involved radical radiation therapy and chemotherapy with little or no role for surgery. However, the potential effect of irradiation on facial growth and the appearance of secondary irradiation-induced tumors has raised the question as to whether surgery may once again play a role in the treatment of these patients. Advances in skull base and reconstructive surgery and microsurgical techniques have permitted a reconsideration of initial ablative surgery. The head and neck surgical team must be prepared to respond in those patients in whom craniofacial development is at risk or recurrence has occurred after radical chemotherapy and/or radiation therapy.

Child, Preschool↗

PubMed1991

Microvascular reconstruction of major arteries in neonates and small children.

Arterial injuries in neonates and children under 2 years of age, although relatively uncommon, should be treated by prompt exploration and reconstruction using microvascular techniques. In the past, a reluctant attitude has prevailed in cases involving neonates or infants because of small vessel caliber and the problem of spasm. We reviewed our experience with 9 nonreplantation, arterial reconstructions in children under 2 years of age. The most frequent age at reconstruction was 1.0 month and extended from the immediate newborn period to 24 months of age. All patients were at risk for tissue necrosis. Eight children sustained iatrogenic injuries related either to invasive catheter manipulation (n = 6) or operative transection (n = 2). The ninth patient required reconstruction of the subclavian artery sacrificed during excision of a malignant tumor. There were 5 femoral, 1 subclavian, 1 brachial, 1 posterior tibial, and 1 radial artery repairs. Direct arterial repair was accomplished in one patient with a brachial artery thrombus and another with a transected superficial femoral artery. Reversed saphenous vein grafts were used in the remaining patients. Iatrogenic dissection of the ipsilateral iliac artery necessitated use of a femofemoral bypass graft to achieve adequate inflow in one newborn. There were no operative deaths, no reexplorations, and normal perfusion was restored to all involved extremities. We conclude that microvascular technique allows early, successful arterial reconstruction and limb salvage in neonates and small children.

Arteries↗

PubMed1991

Correction of constriction rings.

A refinement in the correction of deep and shallow constriction rings, in which subcutaneous fat and fascial flaps are advanced into the defect to prevent recurrent contour deformities, is presented. A straight-line dorsal closure is preferred, with Z-plasties placed along the side of the digits, forearm, or arm. Long-term follow-up is presented in 58 patients with 116 constriction rings corrected by either traditional serial Z-plasties of skin (n = 61 rings) or this new method of contour correction (n = 55 rings). Specific correction of soft tissue is recommended when tissue is available.

Adipose Tissue↗

PubMed1991

Bilateral lower limb salvage with free flaps in a patient with sickle cell ulcers.

A patient with long-standing bilateral circumferential lower extremity sickle cell ulcerations refractory to conservative management was successfully treated with bilateral free latissimus muscle transfers. This report confirms the value of free tissue transfer in the treatment of these difficult skin ulcerations. Exchange transfusions that brought the SS hemoglobin below 30% were crucial to the prevention of sickling in the microcirculation of the flap during its obligate period of ischemia. Furthermore, they protected the flap during a period of ischemia that exceeded 4 hours following a postoperative arterial thrombosis. In the presence of severe thrombocytosis associated with sickle cell disease, prophylactic treatment with aspirin may be of significant value.

Adult↗

PubMed1991

Prefabrication of composite free flaps through staged microvascular transfer: an experimental and clinical study.

The feasibility of prefabricating free flaps by inducing, through the process of staged reconstruction, an arteriovenous bundle and its surrounding fascia to perfuse a selected block of tissue was investigated experimentally and clinically. Sixteen rat knee joints were wrapped with their ipsilateral superficial inferior epigastric (SIE) fascia. In 8 joints, the composite flaps were resected en bloc and were immediately replaced orthotopically pedicled upon the superficial inferior epigastric vessels. In the remaining joints, the resection and orthotopic transfer were performed 2 weeks later. Only the joints in the latter group, which benefited from the staging period, were found to be perfused. The long finger proximal interphalangeal joint of a child was reconstructed by the staged microvascular transfer of his second toe proximal interphalangeal joint. At the first stage, a temporalis fascia flap was wrapped around the toe proximal interphalangeal joint and revascularized to the dorsalis pedis vessels. Six weeks later, the joint and its temporalis fascia envelope were dissected, and the "prefabricated" joint flap was transferred to the hand and revascularized to the wrist vessels. Bony union progressed uneventfully with excellent recovery of the range of motion. We conclude that regardless of the indigenous vascular anatomy, an unlimited array of composite free flaps can be constructed and transferred based on induced large vascular pedicles.

Animals↗

PubMed1991

Apert syndrome. Classification and pathologic anatomy of limb anomalies.

This article contains a summary and classification of the major abnormalities seen in both upper and lower extremities associated with Apert syndrome. Whereas rationale and results of treatment of the thumb, hand, foot, shoulder, and elbow can be found in specific articles in this issue, detailed analysis of the anatomy found in the wrist and hand is presented in this article.

Acrocephalosyndactylia↗

PubMed1991

The anatomy and management of the thumb in Apert syndrome.

The thumb in a child with Apert syndrome provides the key to hand function. The characteristic "hitchhiker" posture or radial clinodactyly of these short but broad digits is caused by an abnormal proximal phalanx. Along with the shortened and radially deviated proximal phalanx, the first webspace (thumb-index) is always deficient. This article details the authors' anatomic observations of these abnormal thumbs and their rationale for treatment.

Acrocephalosyndactylia↗

PubMed1991

The shoulder, elbow, and forearm in Apert syndrome.

Clinical and radiographic follow-up study of the elbow and shoulder in 19 children and adults with Apert syndrome demonstrates that these two joints are affected to varying degrees. Shoulder motion is never normal and may be quite restricted, with the progression of growth abnormalities of the proximal humerus and accompanying glenoid dysplasia. Limitation of abduction is secondary to an impingement of an overgrown greater tuberosity upon the acromion. Clinically, these children appear to have anterior subluxations. Elbow motion is limited in a much smaller percentage of patients and was not a significant problem unless elbow fusion occurred. A radiocapitellar dysplasia was associated with a mean 30-degree extension loss in 7 of 19 patients. Two patients had no elbow motion.

Acrocephalosyndactylia↗

PubMed1991

The foot in Apert syndrome.

Foot deformity in Apert syndrome is very characteristic and predictable. Progressive synostosis occurs on what is presumably an unsegmented cartilaginous mass. The first ray shortens with medial deviation of the great toe, secondary to growth abnormality and a delta phalanx. The two phalanx digits characteristically go on to fusion, with maintenance of minimal motion at the metatarsal phalangeal joints. The midfoot and hindfoot progress to characteristic fusion in a supinated position. There is prominence of the fifth metatarsal with callosities under the fifth and third metatarsal heads in all patients. Orthotic and surgical management of these conditions is necessary to ensure maximal function in the symptomatic Apert patient.

Acrocephalosyndactylia↗

PubMed1991

Apert bibliography.

Explore the source record for details and available documents.

Acrocephalosyndactylia↗

PubMed1990

Nerve regeneration and reinnervation after limb amputation and replantation: clinical and physiological findings.

A 22-year-old male was studied 3 1/2-4 1/2 years after a traumatic section-avulsion amputation of the left upper extremity at the level of the distal humerus. The arm was reattached after a cold ischemia time of 4-5 hours and good vascularization was obtained. The ulnar nerve was repaired early with an end-to-end juncture while the median and radial nerves were repaired after seven months delay using a combination of vascularized radial nerve and nonvascularized sural nerve grafts. Some intrinsic hand muscle function had recovered. Pin-prick and touch sensation was present in all digits, although localization of touch stimulation was poor. Evoked motor responses had recovered by 25-50% of control amplitude in ulnar-innervated and by 10-25% in median-innervated muscles. Amplitudes of sensory responses from digit V had recovered by 25% and from digits I and III by 1-5%. Fast-adapting touch receptors had become reinnervated. There was electrophysiological evidence of aberrant sensory regeneration and of abnormal connections between sensory and motor fibers. Digital blood flow measurements suggested the presence of vascular obstruction in vessels of the replanted upper extremity. However, the digital vasoconstriction during cold exposure indicated regeneration of sympathetic nerve fibers.

Adult↗

PubMed1990

The in vivo auto-oxidation of polyether polyurethane by metal ions.

The first large scale use of polyether polyurethane elastomers in long term human implants was as insulation for cardiac and neurologic pacing leads. While the performance of these polymers has generally been very good over a 14-year period, several failure mechanisms have been discovered that involve interactions between the devices, materials and the body. One of these is auto-oxidation of soft segment ether through the intermediate action of certain transition metal ions, derived from conductor wires by corrosion processes. Biologically produced oxidants appear to be an accelerating factor. In this study, Pellethane 2363-80A tubing containing conductor coils or mandrels of various metals or controls were implanted in rabbits. Explants were analyzed as a function of implant time by optical and scanning electron microscopy, electron dispersive analysis by X-ray, stress-strain, FTIR, GPC and AA spectrophotometry. Only cobalt produced bulk oxidative degradation while surface damage was found in the presence of cobalt bearing alloys. No evidence of significant auto-oxidation was found in the presence of silver, nickel, chromium, molybdenum, iron, titanium, platinum, 304 stainless steel, glass or empty tubing. The combination of polyether polyurethane and metals (especially those containing cobalt) in an implantable device must be carefully evaluated for biostability prior to human use.

Biocompatible Materials↗

PubMed1989

Surgical treatment of thoracic deformity in Poland's syndrome.

In 1841, Poland described congenital deficiency of the pectoralis major and minor muscles associated with syndactyly. This syndrome is a spectrum, often involving chest wall and breast deformity as well. Identification of the various musculoskeletal components involved permits optimal thoracic reconstruction in the small proportion of patients who will require it. From 1955 to 1988, 75 patients (40 males and 35 females) with Poland's syndrome were treated or evaluated. Patients with isolated deficiencies of the pectoral muscles, breast, or hand deformity were excluded. The complex was right-sided in 44 patients, left-sided in 30, and bilateral in one. The pectoralis minor and the costal portion of the pectoralis major muscle were absent in all patients. Hand anomalies were present in 50 patients. Athelia and/or amastia were noted in 37 patients. In ten patients, the rib cage deformity required reconstruction, and in three cases, rib or cartilage grafts were needed for complete repair. Often unappreciated in these cases is the significant rotation of the sternum toward the involved side and contralateral carinate deformity. Correction is achieved by bilateral subperichondrial costal cartilage resection and sternal osteotomy (seven of ten patients), thus allowing anterior displacement and orthorotation of the sternum. Chest wall reconstruction must be tailored to the requirements of each patient. No intraoperative or postoperative complications occurred in these ten patients. In males without rib cage deformity, generally no treatment is required to replace the absent pectoral muscles, although in two cases rotation of the latissimus dorsi muscle was performed. In all females, reconstruction of the ipsilateral breast is required at full development.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗

PubMed1989

Comparative response of muscle and subcutaneous tissue pH during arterial and venous occlusion in musculocutaneous flaps.

Clinical measures often fail to detect early tissue ischemia in inadequately perfused flaps. This study investigates the application of a new pH electrode system to monitor tissue metabolism continuously in porcine and human musculocutaneous flaps. Bilateral rectus abdominis flaps based on the deep inferior epigastric pedicle were elevated in eight mixed-breed pigs. Tissue pH was measured in the subcutaneous and muscular layers with miniature glass-tip electrodes. The deep inferior epigastric artery and vein were serially and then concomitantly occluded for 20-minute periods. The decrease in tissue pH was greater following either arterial or pedicle occlusion (each 0.21 +/- 0.03 units) when compared with venous occlusion (0.10 +/- 0.02 units; p less than 0.02). Changes in muscle and subcutaneous hydrogen ion concentration were similar during arterial and venous occlusions (probability not significant). Measurement of subcutaneous pH appears to be a reliable experimental and clinical physiological tool for detecting early tissue ischemia in reconstructive flaps.

Animals↗