Ahmed Deniwar

Bio: Ahmed Deniwar is an academic researcher from Tulane University. The author has contributed to research in topics: Medicine & Recurrent laryngeal nerve. The author has an hindex of 10, co-authored 17 publications receiving 313 citations.

Assessment of Vocal Fold Function Using Transcutaneous Laryngeal Ultrasonography and Flexible Laryngoscopy.

Abstract: Importance Evaluation of preoperative and postoperative vocal fold function is important in patients undergoing thyroid or parathyroid surgical procedures. Transcutaneous laryngeal ultrasonography (TLUSG) has been proposed as a promising noninvasive technique and alternative to flexible fiberoptic laryngoscopy. Objective To determine whether TLUSG can be an alternative to flexible laryngoscopy in evaluating vocal fold function. Design, Setting, and Participants A prospective study was performed from March 1, 2013, to July 31, 2014. Patients who were scheduled to undergo thyroid or parathyroid surgery by a single surgeon at a North American, university-based tertiary care center and who agreed to undergo preoperative and postoperative TLUSG and flexible fiberoptic laryngoscopy were enrolled. Patients were divided into 2 groups: nonoverweight (body mass index [calculated as weight in kilograms divided by height in meters squared] Interventions Preoperative and postoperative TLUSG and flexible fiber optic laryngoscopic assessments of vocal fold function. Main Outcomes and Measures The findings of TLUSG and flexible fiber optic laryngoscopy were compared for all patients and each body mass index group to assess the accuracy of TLUSG in assessing vocal fold function. Results A total of 250 patients (500 vocal folds) underwent evaluation, of whom 208 (83.2%) were women and with a mean (SD) age of 52.7 (14.3) years. On flexible fiberoptic laryngoscopy findings, 13 patients had preoperative vocal fold paralysis (VFP), and 14 postoperative new incidents of VFP were identified. Only 7 (53.9%) of the preoperative cases of VFP and 15 (55.6%) of the postoperative cases of VFP were identified by TLUSG. The sensitivity, specificity, and accuracy of preoperative TLUSG were 53.8%, 50.5%, and 50.6%, respectively; for postoperative TLUSG, 55.6%, 38.7%, and 39.6%, respectively. In the nonoverweight group, the preoperative TLUSG sensitivity, specificity, and accuracy were 100%, 70.0%, and 70.5%, respectively; in the overweight-obese group, 45.4%, 43.4%, and 43.5%, respectively (odds ratio, 3.16; 95% CI, 2.06-4.84;P Conclusions and Relevance When evaluation of vocal fold function is indicated in patients undergoing thyroid and parathyroid surgery, TLUSG should not be considered as an alternative to the current practice of flexible fiberoptic laryngoscopy. Adequate ultrasonographic visualization of the vocal folds and arytenoids is challenging, especially in overweight and obese patients and in the postoperative setting.

Robotic Thyroidectomy Versus Nonrobotic Approaches: A Meta-Analysis Examining Surgical Outcomes

Abstract: Background Robotic surgery has been recently used as a novel tool for remote access thyroid surgery. We performed a meta-analysis of the current literature to examine the safety and oncological efficacy of robotic surgery compared to endoscopic and conventional approaches for different thyroid procedures. Methods A systematic search of the online data bases was done using the following (MeSH) terms "robotic surgery," "robotic thyroidectomy," "robot-assisted thyroidectomy," and "robot-assisted thyroid surgery." Outcomes measured included total operative time, length of hospital stay, postoperative thyroglobulin levels, and postoperative complications. Statistical differences were analyzed between groups through the standard means and/or relative risk by using STATA analytical software. Results In this study, 144 articles were identified; of which 18 of them met our inclusion criteria, totaling 4878 patients. Robotic approach was associated with longer total operative time (mean difference of 43.5 minutes) when compared to the conventional cervical approach (95% CI = 20.9-66.2; P < .001). Robotic approach was also found to have a similar risk of total postoperative complications when compared to the conventional and endoscopic approaches. Conclusion Robotic thyroid surgery is as safe, feasible and provides similar periperative complications and oncological outcomes when compared to both, conventional cervical and endoscopic approaches. However, robotic thyroid surgery is associated with longer operative time when compared to the conventional open approach.

Electrophysiological neural monitoring of the laryngeal nerves in thyroid surgery: review of the current literature.

Abstract: Recurrent laryngeal nerve (RLN) injury is one of the most common complications of thyroid surgery. RLN injury can cause vocal cord paralysis, affecting the patient's voice and the quality of life. Injury of the external branch of the superior laryngeal nerve (EBSLN) can cause cricothyroid muscle denervation affecting high vocal tones. Thus, securing the laryngeal nerves in these surgeries is of utmost importance. Visual identification of the nerves has long been the standard method for this precaution. Intraoperative neuromonitoring (IONM) has been introduced as a novel technology to improve the protection of the laryngeal nerves and reduce the rate of RLN injury. The aim of this article is to provide a brief description of the technique and review the literature to illustrate the value of IONM. IONM can provide early identification of anatomical variations and unusual nerve routes, which carry a higher risk of injury if not detected. IONM helps in prognosticating postoperative nerve function. Moreover, by detecting nerve injury intraoperatively, it aids in staging bilateral surgeries to avoid bilateral vocal cord paralysis and tracheostomy. The article will discuss the value of continuous IONM (C-IOMN) that may prevent nerve injury by detecting EMG waveform changes indicating impending nerve injury. Herein, we are also discussing anatomy of laryngeal nerves and aspects of its injury.

Association of Malignancy Prevalence With Test Properties and Performance of the Gene Expression Classifier in Indeterminate Thyroid Nodules.

Abstract: Importance It is crucial for clinicians to know the malignancy prevalence within each indeterminate cytologic category to estimate the performance of the gene expression classifier (GEC). Objective To examine the variability in the performance of the GEC. Design, Setting, and Participants This retrospective cohort study of patients with Bethesda category III and IV thyroid nodules used single-institution data from January 1, 2013, through February 29, 2016. Expected negative predictive value (NPV) was calculated by adopting published sensitivity and specificity. Observed NPV was calculated based on the true-negative rate. Outcomes were compared with pooled data from 11 studies published January 1, 2010, to January 31, 2016. Results A total of 145 patients with 154 thyroid nodules were included in the study (mean [SD] age, 56.0 [16.2] years; 106 females [73.1%]). Malignancy prevalence was 45%. On the basis of this prevalence, the expected NPV is 85% and the observed NPV is 69%. If the prevalence is assumed to be 25%, the expected NPV would be 94%, whereas the observed NPV would be 85%. Pooled data analysis of 11 studies comprising 1303 participants revealed a malignancy prevalence of 31% (95% CI, 29%-34%) and a pooled NPV of 92% (95% CI, 87%-96%). Conclusions and Relevance In this study, variability in the performance of the GEC was not solely a function of malignancy prevalence and may have been attributable to intrinsic variability of the test sensitivity and specificity. The utility of the GEC in practice is elusive because of this variability. A better definition of the GEC’s intrinsic properties is needed.

Percutaneous ethanol injection vs reoperation for locally recurrent papillary thyroid cancer: a systematic review and pooled analysis.

Abstract: Importance Reoperation for recurrent papillary thyroid cancer (PTC) can be associated with a high rate of complications and failure to provide lasting remission. Percutaneous ethanol injection (PEI) may be an effective nonsurgical management option for locally recurrent PTC. Objective This systematic analysis of the current literature compares the efficacy and complications related to PEI vs reoperative surgical intervention for treatment of locally recurrent PTC. Data Sources Original studies were identified using the keywords “thyroid/ethanol” and “recurrent thyroid cancer/repeat surgery.” Study Selection Studies evaluating reoperation or PEI for lymph node metastases in patients with primary surgery of total thyroidectomy with appropriate lymph node dissection where indicated were included in the analysis for both reoperation and PEI. Animal studies, single case reports, and studies with fewer than 10 lesions were excluded. Data Extraction and Synthesis Outcomes included interval to detection of recurrence, success and failure rates, recurrence rates, complication rates, and follow-up duration. Between-group outcome differences were calculated using random-effects models, and pooled data cross-tabulation and logistic regression analysis were used. Results In all, 945 publications were identified, and 27 studies met the inclusion criteria. There were no studies that directly compared the 2 treatment techniques. A total of 1617 patients were included in this analysis; 168 (11.4%) were treated with PEI, and 1449 (88.6%) were treated with reoperation. Reoperation was successful in 94.8% of cases compared with an 87.5% success rate for PEI (odds ratio [OR], 2.58; 95% CI, 1.55-4.31;P Conclusions and Relevance High-quality, well-designed studies are needed to evaluate the feasibility of incorporating PEI into the treatment protocol of PTC. Although presently inferior to reoperation, PEI has the potential to be a widely accepted and effective nonsurgical treatment option for limited recurrent PTC in poor surgical candidates or patients seeking to avoid multiple reoperations.

The Diagnosis and Management of Thyroid Nodules: A Review

Abstract: Importance Thyroid nodules are common, being detected in up to 65% of the general population. This is likely due to the increased use of diagnostic imaging for purposes unrelated to the thyroid. Most thyroid nodules are benign, clinically insignificant, and safely managed with a surveillance program. The main goal of initial and long-term follow-up is identification of the small subgroup of nodules that harbor a clinically significant cancer (≈10%), cause compressive symptoms (≈5%), or progress to functional disease (≈5%). Observations Thyroid function testing and ultrasonographic characteristics guide the initial management of thyroid nodules. Certain ultrasound features, such as a cystic or spongiform appearance, suggest a benign process that does not require additional testing. Suspicious sonographic patterns including solid composition, hypoechogenicity, irregular margins, and microcalcifications should prompt cytological evaluation. Additional diagnostic procedures, such as molecular testing, are indicated only in selected cases, such as indeterminate cytology (≈20%-30% of all biopsies). The initial risk estimate, derived from ultrasound and, if performed, cytology report, should determine the need for treatment and the type, frequency, and length of subsequent follow-up. Management includes simple observation, local treatments, and surgery and should be based on the estimated risk of malignancy and the presence and severity of compressive symptoms. Conclusions and Relevance Most thyroid nodules are benign. A diagnostic approach that uses ultrasound and, when indicated, fine-needle aspiration biopsy and molecular testing, facilitates a personalized, risk-based protocol that promotes high-quality care and minimizes cost and unnecessary testing.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

Abstract: Objective:To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.Background:Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in th

Active Surveillance for Patients With Papillary Thyroid Microcarcinoma: A Single Center's Experience in Korea.

Abstract: Context Papillary thyroid microcarcinoma (PTMC) usually has an excellent prognosis. Objective To evaluate the three-dimensional structures of PTMCs, using serial neck ultrasonography (US) in patients under active surveillance. Design and setting A retrospective cohort study. Participants In total, 192 patients diagnosed with PTMC under active surveillance for >1 year were included in a median 30-month follow-up. Changes in tumor size were evaluated not only using the maximal tumor diameter but also the tumor volume. Results The median age of patients was 51.3 years and 145 patients (76%) were female. The median initial maximal tumor diameter and tumor volume were 5.5 mm and 48.8 mm3, respectively. The tumor size increased in 27 patients (14%); 23 patients showed a tumor volume increase >50% without a maximal diameter increase of ≥3 mm. The other four patients had both an increasing tumor volume and increasing maximal tumor diameter ≥3 mm. One patient (0.5%) had newly appeared cervical lymph node (LN) metastasis at 3 years after the initial diagnosis. There were no significant risk factors associated with increased tumor size, such as age, sex, or Hashimoto thyroiditis. Twenty-four patients (13%) underwent delayed thyroid surgery at a median of 31.2 months and seven (29%) had cervical LN metastasis on pathologic examination. Conclusion Some PTMCs could grow significantly after a relatively short period of active surveillance. We also found that the change in tumor volume was more sensitive to detect tumor progression than the change in the maximal tumor diameter.

Robotic and Endoscopic Thyroid Surgery: Evolution and Advances

Abstract: To minimize surgical morbidity and neck scarring, minimally invasive thyroidectomy and robotic/endoscopic thyroidectomy via cervical, axillary, anterior chest, breast, postauricular or transoral approaches have been developed over the past 20 years In this article, we review the evolution of robotic and endoscopic thyroid surgery and recent advances Among remote access approaches, the gasless transaxillary approach, bilateral axillo-breast approach, postauricular facelift approach, and transoral vestibular approach are in common use today Each procedure has its own advantages and disadvantages Therefore, we need to understand these advantages and limitations, and to select the appropriate method for each patient The most significant advantage of remote access thyroidectomy is its excellent cosmesis The complication rate is similar in patients undergoing a remote access approach and those undergoing conventional surgery if the former is performed by experienced surgeons Operative time is significantly longer in remote access thyroidectomy In conclusion, remote access thyroidectomy is feasible and its outcomes are comparable to those of conventional transcervical thyroidectomy in highly selected patients