Adrian Harvey

Robotic thoracoscopic mediastinal parathyroidectomy for persistent hyperparathyroidism: case report and review of the literature.

Recurrent and persistent primary hyperparathyroidism remains a significant surgical challenge. Abnormal, hypersecreting parathyroid glands are found in ectopic locations in up to 15% to 20% of patients. A small portion of these ectopic glands will be found in the mediastinum at a location that precludes removal through the traditional cervical incision. Minimally invasive approaches to these glands are desirable because of the significant morbidity, pain, and hospital stay associated with sternotomy or thoracotomy. Recently, robotic approaches have been described for mediastinal parathyroids. We report a case of young woman with persistent primary hyperparathyroidism who was cured after undergoing robotic thoracoscopic mediastinal parathyroidectomy using radiooperative and intraoperative parathyroid hormone guidance.

High-Probability Features of Primary Aldosteronism May Obviate the Need for Confirmatory Testing Without Increasing False-Positive Diagnoses

This retrospective review examined all primary aldosteronism (PA) adrenal vein sampling (AVS), diagnoses, and outcomes from an endocrine hypertension unit where confirmatory testing was abandoned in 2005 to determine the potential rate of false‐positive diagnoses. Patients with outcome‐verified PA (surgical patients) were compared with patients with high‐probability PA (nonsurgical but high aldosterone‐renin ratio, imaging abnormalities, and/or hypokalemia) or possible PA (nonsurgical, no features besides mild elevation of aldosterone‐renin ratio, a potential false diagnosis of PA). Of 83 patients, 58% had unilateral PA and 42% had bilateral aldosteronism. Less than 3% of the cohort showed bilateral aldosteronism without hypokalemia or computed tomographic findings, potentially representing the false‐positive PA diagnosis rate with omission of confirmatory tests in this population. In a hypertension referral unit enriched in high‐probability PA cases and where high AVS success is achieved, omission of a PA confirmatory test yields a high rate of surgical diagnosis with few potential false‐positive diagnoses.

Performing under pressure: Quiet eye training improves surgical knot-tying performance

BACKGROUND We examined the effectiveness of traditional technical training (TT) and quiet eye training (QET) on the performance of 1-handed square knot tying among first-year surgery residents under normal and high-anxiety conditions. METHODS Twenty surgery residents were assigned randomly to 1 of 2 groups and completed pretest, training, and simple and complex retention tests under conditions of high and low anxiety. The TT group received traditional instruction on improving hand movements; the QET group received feedback on their gaze behaviors. Participants wore an eye tracker that recorded simultaneously their gaze and hand movements. Dependent variables were knot tying performance (%), quiet eye duration (%), number of fixations, and total movement time (s). RESULTS Both groups improved their knot tying performance (P < .05) from pretest to the low anxiety conditions (mean difference: QET, 28%; TT, 17%); however, only the QET group maintained their knot tying performance under the high-anxiety conditions (mean difference: QET, 18%; P < .05), with the TT group decreasing their performance close to pretest levels (P > .05). The QET group also demonstrated more efficient gaze and hand movements post training. CONCLUSION These data demonstrate the effectiveness of training gaze behaviors, not only to improve the effectiveness and efficiency of performance, but also to mediate negative effects of anxiety on performance. These findings may have important implications for medical educators and practitioners, as well as surgeons who may be (re)training or learning new procedures.

Quiet eye training improves surgical knot tying more than traditional technical training: a randomized controlled study.

BACKGROUND We examined the effectiveness of technical training (TT) and quiet eye training (QE) on the performance of one-handed square knot tying in surgical residents. METHODS Twenty surgical residents were randomly assigned to the 2 groups and completed pretest, training, retention, and transfer tests. Participants wore a mobile eye tracker that simultaneously recorded their gaze and hand movements. Dependent variables were knot tying performance (%), QE duration (%), number of fixations, total movement time (s), and hand movement phase time (s). RESULTS The QE training group had significantly higher performance scores, a longer QE duration, fewer fixations, faster total knot tying times, and faster movement phase times compared with the TT group. The QE group maintained performance in the transfer test, whereas the TT group significantly decreased performance from retention to transfer. CONCLUSIONS QE training significantly improved learning, retention, and transfer of surgical knot tying compared with a traditional technical approach. Both performance effectiveness (performance outcome) and movement efficiency (hand movement times) were improved using QE modeling, instruction, and feedback.

Catheterization during adrenal vein sampling for primary aldosteronism: failure to use (1-24) ACTH may increase apparent failure rate.

“Successful” adrenal vein catheterization in primary aldosteronism (PA) is often defined by a ratio of >3:1 of cortisol in the adrenal vein vs the inferior vena cava. Non‐use of corticotropin (ACTH) during sampling may increase the apparent failure rate of adrenal vein catheterization due to lower cortisol levels. A retrospective study was performed on all patients with confirmed unilateral PA between June 2005 and August 2011. Adrenal vein sampling (AVS) included simultaneous bilateral baseline samples with repeat sampling 15 minutes after intravenous infusion of 250 μg of Cortrosyn (ACTH‐S). Successful catheter placement was judged as adrenal cortisol:IVC cortisol of >3:1, applied to both baseline and ACTH‐S samples and lateralization of aldosteronism was judged as normalized aldosterone/cortisol (A/C) ratio >3 times the contralateral A/C ratio. In ACTH‐S samples, 94% of right‐sided catheterizations were biochemically successful with 100% success on the left. Among baseline samples, only 47% of right‐ and 44% of left‐sided samples met the 3:1 cortisol criteria. However, 95% of apparent “failed” baseline cortisol sets still showed lateralization of A/C ratios that matched the ultimate pathology. Non–ACTH‐stimulated samples may be incorrectly judged as failed catheter placement when a 3:1 ratio is used. ACTH‐stimulated sampling is the preferred means to confirm catheterization during AVS.

Unadjusted Plasma Renin Activity as a “First-Look” Test to Decide Upon Further Investigations for Primary Aldosteronism

The authors sought to define the 95th percentile of plasma renin activity (PRA) in a sample of patients with confirmed primary aldosteronism (PA) prior to adjustment of medications as a practical “first‐look” test to identify those with very low ultimate likelihood of having PA. The aldosterone to renin ratio (ARR) was measured without adjustment of antihypertensive medications, with further workup as appropriate. Two groups were defined: patients with surgically “confirmed PA” (n=58) and patients with “high‐probability PA” (n=59), defined as having any of the following: computed tomography–confirmed adrenal adenoma plus lateralizing adrenal vein sampling (AVS) without surgery, high ARR and hypokalemia but nonlateralizing AVS, or ARR more than four times the upper limit of normal. The PRA 95th percentile was 1.0 ng/mL/h. All outliers had hypokalemia and two had adrenal adenomas. There was no difference between the confirmed and high probability groups. In the absence of highly suspicious clinical features, patients with unadjusted PRA >1.0 ng/mL/h do not warrant further investigation for PA.

Hyperaldosteronism: Diagnosis, Lateralization, and Treatment

Primary hyperaldosteronism is an important and commonly unrecognized secondary cause of hypertension. This article provides an overview of the current literature with respect to screening, diagnosis, and lateralization. Selection and outcomes of medical and surgical treatment are discussed.

Primary Hepatic Gastrinoma Causing Zollinger-Ellison Syndrome: A Rare and Challenging Diagnosis

The majority of gastrinomas causing Zollinger-Ellison syndrome (ZES) are located in the duodenum or the pancreas. Primary hepatic gastrinomas (PHG) are extremely rare and difficult to diagnose because the liver is the commonest site of metastatic disease and gastrinomas can be very small. Furthermore, gastrinomas are typically slow-growing thus a missed, occult primary tumour may not become evident for many years. The diagnosis of PHG is therefore dependent on a careful search for a primary and long-term biochemical follow-up following curative hepatic resection. We report a case of a 7 cm PHG in a 48 year old man with ZES. Preoperatively, both a basal and stimulated gastrin levels were elevated. Surgical exploration including intraoperative ultrasound and duodenotomy, failed to reveal a primary. Patient underwent a right hepatectomy. Yearly, gastrin and secretin stimulation tests remain normal 6 years following surgery. He remains symptom free off all medication. An additional 26 cases of PHG were found. Including this case, 21 had at least 1 year follow-up, however only eight had greater than 5 years (median 24 months). Post-op gastrin levels were reported in 25, however provocative testing was done in only 10. Persistence and recurrence occurred in one and four, respectively. PHG causing ZES is extremely rare. Although the current literature claims to include 26 additional cases of PHG, without a thorough search for the primary and long-term follow-up data including provocative testing, this diagnosis remains a challenge.

Instant replay: Evaluation of instant video feedback in surgical novices for a laparoscopic gallbladder dissection

BACKGROUND Athletes often use video to improve their technique. We hypothesized that surgical novices given feedback using video-replay would outperform surgical novices given verbal feedback in the performance of a laparoscopic task. METHODS Our study used a prospective, randomized control design. The surgical task involved the laparoscopic dissection of a pig gallbladder. Our participants performed a dissection, pre- and post-traditional or video feedback. Each recording was independently scored by two staff surgeons using the previously validated rating tools. RESULTS There was no significant difference between video feedback or traditional feedback groups in their mean overall or task specific scores. Both traditional and video-feedback groups had a trend towards improved performance post-feedback. CONCLUSIONS No significant difference in performance by both our global assessment metrics or task-specific metrics was observed. Video feedback requires further study to investigate its impact on surgical training.

Ablative Therapies of the Liver and Bone in Medullary Thyroid Cancer

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor derived from the thyroid parafollicular C-cells. Distant metastases are the most common cancer-specific cause of death in patients with MTC. Recent censuses in the USA and Europe suggest that approximately 15 % of MTC patients present with distant metastatic disease.