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Biomedical subjects

N Karp

Publications and source records attributed to N Karp.

11 recordsLinked to original sources

Complications of tissue expansion in a public hospital.

Avoidance of complications in tissue expansion requires careful outpatient observation and consistent follow-up-two factors that are difficult to manage in a city hospital-based population. To determine the complication rate of tissue expanders in a given population, the authors reviewed retrospectively 34 tissue expanders placed in 30 patients at a New York City public hospital over a 7-year period from 1989 to 1996. The mean age of the patients at the time of insertion was 25 years (range, 11 months-65 years). The most common conditions for treatment were nevi (N = 11), burn scars (N = 8), breast reconstructions (N = 8), and spina bifida (N = 4). Complications occurred in 22 of 34 expanders (65%). Complications included deep infection (N = 11), exposure (N = 7), breakdown of the surgical wound (N = 4), cellulitis (N = 3), drainage (N = 1), and deflation (N = 1). Major complications resulted in premature removal in 13 of 34 expanders (38%). Minor complications leading to successful completion of the expansion process occurred with 9 of 34 expanders (27%). No complications were recorded in the remaining 12 of 34 expanders (35%). Although tissue expansion is a potentially safe and effective method of reconstruction, this review should alert the surgeon to the distinct challenges that may be encountered in the public hospital.

Adolescent↗

Treatment of a neuroma-in-continuity of the peroneal nerve with nerve bypass grafts--a case report.

Treatment of neuroma-in-continuity involves neurolysis or resection with interposition nerve grafting of the involved segment. These techniques may be complicated by loss of remaining conduction through axons that were intact prior to surgical neurolysis or grafting. The authors have shown previously that axonal regeneration occurs in an autologous bypass graft in the rat model. They applied this technique to a neuroma-in-continuity of the peroneal nerve of a 22-year-old woman who sustained an injury to the peroneal nerve after arthroscopic surgery, with excellent results. Nerve bypass may be the procedure of choice for treatment of neuroma-in-continuity.

Adult↗

Use of a multiplanar distracter for the correction of a proximal interphalangeal joint contracture.

Proximal interphalangeal (PIP) joint contractures are common complications in hand injuries and conditions such as Dupuytren's contracture. Conventional treatment such as splinting and serial casting may result in inadequate improvement. Operative release of the contracture may be complicated by neurovascular overstretch with injury to the digital nerves or vascular compromise. Gradual distraction of the contracted joint may prevent this neurovascular injury. The multiplanar distracter was designed for three-dimensional distraction of the mandible. Distraction may be obtained in the X, Y, or Z planes. With this device, the angular relationship between two planes may be altered. A 22-year-old male with a PIP joint contraction following replantation failed conventional treatment for release. With the use of a multiplanar distracter, the flexion contraction was reduced from 95 degrees to a more functional 30 degrees using gradual angular distraction. The angle between the proximal and middle phalanges were gradually changed using the ability of the distracter to change the angular relationship in the X-Y plane. At 3 and 6 months postdistraction, the patient has maintained his 30-degree flexion angle. The multiplanar distracter is a simple technique that may be useful for the treatment of PIP joint contractures that fail conventional therapy.

Adult↗

Limb salvage with microvascular free flap reconstruction using simultaneous polytetrafluoroethylene graft for inflow.

Microvascular free flaps have been successfully used to cover defects of the lower extremity. In patients with peripheral vascular disease and lower extremity defects, revascularization with in situ or reversed saphenous vein bypass graft combined with microvascular tissue transfer can salvage a limb that would otherwise be amputated. However, some of these patients may not have autologous vein available for the bypass procedure. We present a case of a 69-year-old man who underwent revascularization with a long polytetrafluoroethylene (PTFE) graft and a simultaneous microvascular free flap reconstruction using the PTFE graft as the inflow. The patient had undergone coronary artery bypass graft with saphenous vein and experienced a nonhealing wound of the distal saphenous vein harvest site and exposure of 8 cm of tibia. Angiogram revealed a significant stenosis of the common iliac artery, occluded superficial femoral artery, faint filling of the profunda femoris artery, and a faintly reconstituted posterior tibial artery. Because the patient had no available saphenous vein for bypass, he underwent an axillary-profunda and profunda-posterior tibial artery bypass with PTFE. A rectus abdominus microvascular free flap with direct anastomosis of the inferior epigastric artery to the PTFE was used to cover the exposed bone. The patient currently ambulates without difficulty. Limb salvage using bypass with PTFE combined with simultaneous microvascular free flap reconstruction is possible in selected patients.

Aged↗

Lengthening the human mandible by gradual distraction.

Lengthening of the mandible by gradual distraction was performed on four young patients (average age 78 months). The amount of mandibular bone lengthening ranged from 18 to 24 mm; one patient with Nager's syndrome underwent bilateral mandibular expansion. Following the period of expansion, the patients were maintained in external fixation for an average of 9 weeks to allow ossification. The patients were followed for a minimum of 11 months to a maximum of 20 months with clinical and dental examinations as well as photographic and radiographic documentation. The technique holds promise for early reconstruction of craniofacial skeletal defects without the need for bone grafts, blood transfusion, or intermaxillary fixation.

Bone Lengthening↗

The risk of carcinoma in wire localization biopsies for mammographically detected clustered microcalcifications.

A total of 183 consecutive patients undergoing biopsies for unilateral microcalcifications concentrated in one or more segments of the breast in the absence of any palpable findings were analyzed to characterize their risk of cancer. Biopsy findings were benign in 86 patients (47%) and malignant in 97 (53%). Of the clinical and mammographic characteristics evaluated, an increasing number of linear microcalcifications, either without a dominant density (p = 0.014) or with a dominant density (p = 0.019) and the presence of heterogeneous microcalcifications (p = 0.055), were associated with a significantly increased risk of malignancy. Conversely a fibronodular parenchymal pattern (p = 0.008) was associated with a significantly decreased risk of malignancy. A high-risk group was identified, 95% (40/42) of whom had malignant biopsy findings, whose mammograms had more than 10 linear microcalcifications not associated with a dominant density (16/17) or at least one linear microcalcification associated with a dominant density (24/25). Conversely a low-risk group for cancer was identified, 88% (28/32) of whom had benign biopsy findings, whose mammograms had exclusively punctate microcalcifications within a fibronodular parenchymal milieu (26/30) or demonstrated some change in the configuration of the microcalcifications on the various mammographic views (10/10). For the remaining 109 patients there was an almost equal division between malignant and benign diagnoses (49% vs 51%).

Adenofibroma↗

Family support.

States are gradually developing programs to support families with special needs, but progress is uneven. Some States offer exemplary models and others offer virtually nothing to support families. Value-based, family-centered, accessible, equitable family support programs are greatly needed in every State by the year 2000, at the latest. This will send a message to people with disabilities and their families that we value them, care about them, and want them to be part of their communities. In the words of some family support program participants: "Even though our daughter has multiple handicaps, our desire is to care for her at home, in a loving environment that all children should have the opportunity to experience." "It allows us to keep our daughter at home and file the possibility of putting her in an institution."

Child↗

A model of microvascular oxygen transport in sickle cell disease.

The model of local control of oxygen delivery in the microvasculature developed by H. J. Granger and A. P. Shepherd (1973, Microvasc. Res. 5, 49-72) was extended to describe microcirculatory blood flow in sickle cell disease. Two major characteristics of sickle cell blood were incorporated into the model: an abnormal blood viscosity which is dependent on the degree of hemoglobin oxygen saturation and hematocrit, and a reduced affinity of hemoglobin (Hb) for oxygen. Sickle cell blood viscosity as a function of oxygen saturation and hematocrit was modeled empirically based upon existing data. Alterations in HbO2 affinity were studied in the model by introducing P50 as an independent variable. The altered oxygen supply/demand relationship in sickle cell disease was simulated following an increase in tissue metabolic demand and a decrease in arteriolar blood flow. The results were analyzed to evaluate the roles of the various rheological characteristics of sickle cell blood in affecting microcirculatory dynamics and tissue oxygen delivery. It was demonstrated that, within the hematocrit range of 20 to 45%, the elevation of P50 from 27 to 38 mm Hg in sickle cell blood is adequate to compensate for the diminished O2 content, despite an elevated blood viscosity, and maintain near normal tissue pO2.

Anemia, Sickle Cell↗

Arteriovenous malformation in a patient with Bannayan--Zonana syndrome.

Bannayan-Zonana syndrome (BZS) is a genetic disorder with autosomal dominant inheritance characterized by macrocephaly and multiple hamartomas of mesodermal origin. Here we present a patient with BZS manifested by many of the classic features, as well as a high-flow upper extremity arteriovenous malformation (AVM). Although this rare syndrome was initially described in 1971, to our knowledge, this is the first report showing an association of AVM with BZS and the first report of this syndrome in the radiologic literature.

Abnormalities, Multiple↗

Successful multimodal therapy for kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon: case report and review of the literature.

We present the management challenge provided by a patient with kaposiform hemangioendothelioma associated with Kasabach-Merritt phenomenon. A female child presented at 14 months of age with an ecchymotic swelling of her right upper arm and axilla. Subsequently, she developed profound thrombocytopenia and hypofibrinogenemia (Kasabach-Merritt phenomenon). Biopsy of the lesion revealed kaposiform hemangioendothelioma, which has been reported as the predominant pathologic diagnosis associated with Kasabach-Merritt phenomenon. To achieve involution of the lesion and preserve function of the arm, the following interventions were involved: embolization, systemic interferon, cyclophosphamide, epsilon aminocaproic acid, and compression therapy. The clinical management of this patient was formidable until we arrived at the proper combination of therapies. Multimodal intervention may be required to manage fastidious hemangioendotheliomas of childhood, achieve clinical improvement, and prevent further morbidity.

Female↗