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Biomedical subjects

Satish Govindaraj

Publications and source records attributed to Satish Govindaraj.

9 recordsLinked to original sources

Allograft tracheoplasty technique for management of refractory tracheal stenosis.

OBJECTIVES: Extensive tracheal airway defects represent a clinical dilemma. Although resection and reanastomosis and staged tracheoplasty may prove beneficial in some cases, recurrent or extensive circumferential stenosis remains a reconstructive challenge. We report the use of the allograft tracheoplasty technique for the reconstruction of recurrent, extensive defects of the trachea and cricoid. METHODS: Nine consecutive patients with recurrent tracheal stenosis were treated with the two-stage allograft tracheoplasty technique. A retrospective review was performed to evaluate for prior surgery, length of stenosis, surgical technique, and outcome. All 9 patients underwent multiple surgical procedures for acquired tracheal stenosis (average, 3.4 procedures) before undergoing the allograft tracheoplasty technique. Before surgery, all patients were tracheotomy-dependent. RESULTS: The patients were assessed 8 to 39 months after allograft tracheoplasty. The primary airway disorders included postintubation stenosis (n = 6), surgical resection for malignancy (n = 1), and idiopathic stenosis (n = 2). Three defects involved 30% to 60% of the cricoid cartilage, and 4 defects were complete circumferential tracheal defects. Five patients underwent an island deltopectoral flap for closure of the tracheoplasty site. One patient had a superficial wound infection at the cartilage recipient site, and 1 patient had a hematoma at the deltopectoral flap donor site. All 9 patients were successfully decannulated without shortness of breath, stridor, or recurrent stenosis at the time of follow-up. CONCLUSIONS: Allograft tracheoplasty is a new technique for the reconstruction of recurrent tracheal stenosis. It appears to be reliable for extensive airway defects that are refractory to conventional tracheoplasty techniques.

Adult↗

Reepithelialization of orthotopic tracheal allografts prevents rejection after withdrawal of immunosuppression.

Prior work has demonstrated that immunosuppressed orthotopic tracheal allografts undergo progressive reepithelialization over a 48-day period with recipient-derived tracheal epithelium. We hypothesized that reepithelialization of tracheal allografts would prevent rejection after withdrawal of immunosuppression. BALB/c murine tracheal grafts were transplanted orthotopically into either syngeneic or allogeneic C57/BL6 recipients. The recipients were either not immunosuppressed, immunosuppressed with cyclosporine A (10 mg/kg per day) continuously, or immunosuppressed for 48 days and then withdrawn from immunosuppression. The grafts were assessed for acute and chronic rejection 10 days and 50 days after immunosuppression withdrawal. The immunosuppressed allograft recipients maintained a ciliated epithelium acutely and chronically after immunosuppression withdrawal. Ten days after immunosuppression withdrawal, there was a mild cellular infiltrate, which resolved 50 days after withdrawal. Electron microscopy, lymphocyte subpopulation assays, and lamina propria analysis demonstrated that immunosuppression withdrawal did not result in tracheal allograft rejection. In vitro and in vivo assessments did not demonstrate evidence of systemic or local immune tolerance. We conclude that reepithelialization of orthotopic tracheal allografts with recipient-derived mucosa prevents rejection of allograft segments. Tracheal transplantation may require only transient immunosuppression, which can be withdrawn after tracheal reepithelialization.

Animals↗

The role of intraoperative rapid parathyroid hormone monitoring for predicting thyroidectomy-related hypocalcemia.

OBJECTIVE: To determine if the intraoperative rapid parathyroid hormone (PTH) assay can be used to accurately predict postoperative calcium levels following total or completion thyroidectomy. DESIGN: A prospective study. SETTING: Tertiary care referral center. PATIENTS: One hundred four patients following a total or completion thyroidectomy.Intervention Intraoperative rapid plasma PTH levels were determined for patients undergoing a total or completion thyroidectomy. MAIN OUTCOME MEASURES: Parathyroid hormone levels were recorded after the induction of anesthesia, before excision, and 5, 10, and 20 minutes after thyroidectomy. Postoperative calcium levels were monitored every 6 hours until hospital discharge. Intraoperative PTH levels were correlated with postoperative calcium levels and clinical symptoms of hypocalcemia. RESULTS: Twenty-two patients (21.2%) required short-term postoperative calcium supplementation, and 2 (1.9%) required long-term calcium replacement. There was a statistically significant difference between those patients requiring calcium replacement and those who did not require calcium supplementation, for postoperative total calcium level (7.2 vs 8.1 mg/dL [1.8 vs 2.0 mmol/L]; P<.001) and ionized calcium level (3.76 vs 4.36 mg/dL [0.94 vs 1.09 mmol/L]; P<.001). In addition, the PTH changes from baseline demonstrated statistically significant differences at 5, 10, and 20 minutes after the excision between the 2 groups (P<.005). In those patients requiring calcium supplementation, 14 (64%) of 22 demonstrated a change in PTH level at 20 minutes of greater than 75% from baseline, and in those patients who did not require postoperative calcium supplementation, 61 (74%) of 82 demonstrated a change in PTH level of less than 75% from baseline (P<.005). CONCLUSION: Intraoperative PTH monitoring may be a useful tool in identifying patients who will not require postoperative calcium supplementation following total or completion thyroidectomy.

Adolescent↗

Effect of fibrin matrix and vascular endothelial growth factor on reepithelialization of orthotopic murine tracheal transplants.

To determine whether the administration of vascular endothelial growth factor (VEGF) alone and in combination with fibrin matrix accelerates murine tracheal allograft reepithelialization, we randomly assigned 40 age-matched mice to 5 experimental groups. BALB/c tracheal grafts were transplanted orthotopically into allogeneic C57BL/6 recipients. The recipients were immunosuppressed with cyclosporine (25 mg/kg per day) and treated with a single topical dose of fibrin matrix, a single topical dose of VEGF, or a single topical dose of a combination of VEGF and fibrin matrix. Thirty-five and 50 days after transplantation, a mixed lymphocyte reaction was performed to assess adequate immunosuppression and the grafts were assessed for rejection, rate and quality of allograft reepithelialization, and cartilage viability. The administration of a combination of fibrin matrix and VEGF to tracheal allografts demonstrated an increased rate of reepithelialization and increased density (37% +/- 2.9%) of morphologically normal ciliated pseudostratified epithelium when compared with an immunosuppressed control group (29.3% +/- 9.1%) 35 days after transplantation. The treated allografts demonstrated no significant change in cartilage viability or rejection. We conclude that the administration of fibrin matrix and VEGF to immunosuppressed tracheal allografts improves the rate and density of tracheal allograft reepithelialization. Carrier-bound growth factors may represent a novel approach to accelerating tracheal allograft reepithelialization and decreasing the need for prolonged immunosuppression following tracheal transplantation.

Animals↗

Parathyroid adenoma autoinfarction: a report of a case.

BACKGROUND: Parathyroid adenoma autoinfarction, although uncommon, is an entity that has been previously reported in the literature; however, the influence of intraoperative parathyroid hormone (PTH) monitoring on therapeutic management has not been reported. METHODS: We present a case of parathyroid autoinfarction that is unique in that it applies a new technology to parathyroid surgery: intraoperative PTH monitoring. RESULTS: Intraoperative PTH monitoring aided in the successful surgical management of this patient. CONCLUSIONS: Intraoperative PTH monitoring can serve as a therapeutic adjunct in the surgical management of parathyroid adenoma autoinfarction.

Adenoma↗

Bone healing and bone substitutes.

With the advent of new biomaterials and surgical techniques, the reconstructive surgeon has a wider range of treatment modalities for the rehabilitation and reconstruction of craniofacial skeletal deformities than ever before. These innovative substances act as true bone graft substitutes, thereby allowing the surgeon to avoid the use of autogenous bone grafts and their associated donor site morbidity. Surgeons have long been interested in producing a composite graft that can heal faster by induction, incorporate with surrounding tissues, and be remodeled to resemble native bone. Currently, there are a host of bone graft substitutes available that vary in both their composition and properties. Craniomaxillofacial surgeons must therefore become comfortable with numerous biomaterials to best tailor the treatment for each patient individually. Ongoing investigations into the next phase of tissue engineering will continue to bring us closer to the ability to regenerate or replace bone.

Biocompatible Materials↗

Acute pancreatitis secondary to isotretinoin-induced hyperlipidemia.

Isotretinoin is a vitamin-A derivative most commonly utilized in the treatment of severe recalcitrant nodulocystic acne. Derangement of lipid metabolism leading to increased triglyceride and cholesterol level has been reported after taking this drug. We report the case of a 43-year-old female with no identifiable risk factor for pancreatitis who developed acute pancreatitis associated with hyperlipidemia while being treated with isotretinoin for hidradenitis suppurativa. To our knowledge, this is the third reported case of isotretinoin-induced hyperlipidemia leading to acute pancreatitis.

Acute Disease↗

Primary sphenoid sinus esthesioneuroblastoma.

Esthesioneuroblastoma is a rare malignant tumor of undifferentiated neuroectodermal origin. Because these tumors are derived from olfactory epithelium, most cases arise in the superior nasal cavity at the level of the cribriform niche. The development of an esthesioneuroblastoma outside of the region in which olfactory epithelium exists is exceedingly rare. We report a rare case of a primary sphenoid sinus esthesioneuroblastoma and discuss the pathogenesis, clinical presentation, and treatment of this rare entity.

Esthesioneuroblastoma, Olfactory↗