Accuracy of adrenal imaging and adrenal venous sampling in diagnosing unilateral primary aldosteronism.

INTRODUCTION: The correct differentiation between unilateral and bilateral adrenal involvement in patients with primary aldosteronism (PA) is of utmost importance to justify surgical treatment. The aim of this study was to determine the accuracy of adrenal imaging compared to adrenal venous sampling (AVS), histopathology and postoperative outcome. METHODS: The data of all patients with unequivocal AVS who underwent unilateral laparoscopic adrenalectomy for primary aldosteronism between May 2004 and April 2015 were entered in this retrospective study. We compared computed tomography (CT) and magnetic resonance imaging (MRI) results with corresponding AVS data, histopathology findings and postoperative outcome. RESULTS: A total of 175 patients underwent unilateral laparoscopic adrenalectomy for primary aldosteronism. AVS was successful in 152 patients and postoperative outcome available in 148 patients. Despite unilateral disease according to AVS results, bilateral normal glands were seen in 15 MRI (17·2%) and 7 CT scans (8·5%), respectively. Unilateral enlargement of the nonhypersecreting adrenal gland was found in three MRI (3·5%) and 10 CT scans (12·2%) of patients who showed aldosterone hypersecretion deriving from the contralateral gland. Fifteen MRI (17·2%) and 18 CT scans (22·0%) revealed bilateral adrenal pathology despite unilateral aldosterone hypersecretion. CONCLUSION: The accuracy of CT and magnetic resonance imaging in predicting unilateral disease is poor. AVS appears to be an essential diagnostic step to identify those patients who may benefit from unilateral adrenalectomy.

Intraoperative near-infrared autofluorescence imaging of parathyroid glands.

OBJECTIVE: To identify parathyroid glands intraoperatively by exposing their autofluorescence using near-infrared light. METHODS: Fluorescence imaging was carried out during minimally invasive and open parathyroid and thyroid surgery. After identification, the parathyroid glands as well as the surrounding tissue were exposed to near-infrared (NIR) light with a wavelength of 690-770 nm using a modified Karl Storz near-infrared/indocyanine green (NIR/ICG) endoscopic system. Parathyroid tissue was expected to show near-infrared autofluorescence, captured in the blue channel of the camera. Whenever possible the visual identification of parathyroid tissue was confirmed histologically. RESULTS: In preliminary investigations, using the original NIR/ICG endoscopic system we noticed considerable interference of light in the blue channel overlying the autofluorescence. Therefore, we modified the light source by interposing additional filters. In a second series, we investigated 35 parathyroid glands from 25 patients. Twenty-seven glands were identified correctly based on NIR autofluorescence. Regarding the extent of autofluorescence, there were no noticeable differences between parathyroid adenomas, hyperplasia and normal parathyroid glands. In contrast, thyroid tissue, lymph nodes and adipose tissue revealed no substantial autofluorescence. CONCLUSION: Parathyroid tissue is characterized by showing autofluorescence in the near-infrared spectrum. This effect can be used to distinguish parathyroid glands from other cervical tissue entities.

Intraoperative optical coherence tomography imaging to identify parathyroid glands.

OBJECTIVE: Optical coherence tomography (OCT) is a non-invasive high-resolution imaging technique that permits characterization of microarchitectural features in real time. Previous ex vivo studies have shown that the technique is capable of distinguishing between parathyroid tissue, thyroid tissue, lymph nodes, and adipose tissue. The purpose of this study was to evaluate the practicality of OCT during open and minimally invasive parathyroid and thyroid surgery. METHODS: During parathyroid and thyroid surgery, OCT images were generated from parathyroid glands, thyroid tissue, lymph nodes, and adipose tissue. The images were immediately assessed by the operating team using the previously defined criteria. Second, the OCT images were blinded with respect to their origin and analyzed by two investigators. Whenever possible the OCT findings were matched to the corresponding histology. RESULTS: A total of 227 OCT images from 27 patients undergoing open or minimally invasive thyroid or parathyroid surgery were analyzed. Parathyroid glands were correctly identified in 69.2%, thyroid tissue in 74.5%, lymph nodes in 37.5%, and adipose tissue in 69.2%. 43 OCT images (18.9%) could not be allocated to one of the tissue types (Table 2). Sensitivity and specificity in distinguishing parathyroid tissue from the other entities were 69% (63 true positive, 13 false negative findings, 15 images where an allocation was not possible) and 66%, respectively (71 true negative, 9 false positive, 28 images where an assessment was not possible). CONCLUSION: OCT is capable of distinguishing between parathyroid, thyroid, and adipose tissue. An accurate differentiation between parathyroid tissue and lymph nodes was not possible. The disappointing results compared to the previous ex vivo study are related to problems handling the endoscopic probe intraoperatively. However, further refinement of this new technology may lead to OCT systems with higher resolution and intraoperative probes that are easier to handle.

Laparoscopic adrenalectomy--10-year experience at a teaching hospital.

BACKGROUND: Minimally invasive adrenalectomy has been adopted as the treatment of choice for benign adrenal tumors. This study aimed to investigate the outcome of laparoscopic adrenalectomies performed over a 10-year period at a teaching hospital. METHODS: All laparoscopic adrenalectomies carried out between 1 April 2000 and 31 March 2010 were evaluated with respect to perioperative management, complications, conversion rate, learning curve, tumor size, and surgically relevant characteristics of different adrenal pathologies. RESULTS: Over a period of 10 years, 215 laparoscopic lateral transabdominal adrenalectomies were carried out for Conn's syndrome (n = 90), Cushing's syndrome (n = 72), pheochromocytoma (n = 30), metastatic disease (n = 8), incidentalomas (n = 10), and other rare adrenal pathologies (n = 5). Morbidity, mortality, and conversion rate were 7.0, 0.9, and 4.2 %, respectively. Patients with Cushing's disease and bilateral adrenalectomy showed a higher complication rate. In retrospect, the indication for a laparoscopic approach was at least questionable in five cases. During these 10 years, four surgeons unfamiliar with the technique received intensive training to a defined plan. CONCLUSIONS: Laparoscopic adrenalectomy represents a safe operating technique associated with few complications and a low conversion rate. Patients with severe Cushing's disease are prone to complications and require intensive monitoring postoperatively. Laparoscopic adrenalectomy is associated with a learning curve, and particular emphasis should be given to surgical training.

Backscattering intensity measurements in optical coherence tomography as a method to identify parathyroid glands.

BACKGROUND AND OBJECTIVE: Previous studies have shown that the use of optical coherence tomography (OCT) permits the differentiation between parathyroid tissue, thyroid tissue, lymph nodes and adipose tissue. We investigated the backscattering intensity profiles of OCT images in order to determine whether significant differences between these tissue types exist. METHODS: Mean backscattering intensity profiles were obtained from OCT images of parathyroid glands, thyroid tissue, lymph nodes and adipose tissue. The profiles were analyzed employing Fisher's Linear Discriminant Analysis (LDA). The results were cross validated employing improved parameter estimation techniques. RESULTS: Mean backscattering intensity profiles from 300 OCT images of 34 patients undergoing thyroid or parathyroid surgery were analyzed. The overall rate of correct classifications was 96.15%. The cross validation employing improved parameter estimation techniques yielded results identical to those derived from Fisher's LDA. CONCLUSION: Besides the individual assessment of OCT images by interpreting morphological criteria, backscattering intensity measurements can reliably distinguish between different tissue entities.

Fistula between cystic artery pseudoaneurysm and cystic bile duct cause of acute anemia one year after laparoscopic cholecystectomy.

We present a case of hemorrhage from a cystic artery pseudoaneurysm one year after laparoscopic cholecystectomy. A 78-year-old male with a history of recurrent melena, hematemesis, and right upper abdominal pain was admitted to our emergency department. His blood pressure was 60/30 mm Hg with a pulse rate of 100 beats per minute. Hemoglobin was 7.6 g/dL and white blood cell count 19500/mm(3). Computed tomography scan of the abdomen and selective digital subtraction arteriography showed a pseudoaneurysm in the region of the former bed of the gallbladder. During gastroscopy, a pulsatile bleeding out of the papilla of Vater was found. Surgery by the open approach confirmed the presence of a cystic artery pseudoaneurysm and showed an additional fistula between the pseudoaneurysm and the cystic bile duct. Resection of the pseudoaneurysm and revision of the common bile duct with implantation of a T-tube was performed. The patient recovered well and was discharged from our hospital three weeks after surgery.

Life-threatening events in patients with pheochromocytoma.

OBJECTIVE: Pheochromocytomas are rare chromaffin cell-derived tumors causing paroxysmal episodes of headache, palpitation, sweating and hypertension. Life-threatening complications have been described in case reports and small series. Systematic analyses are not available. We took an opportunity of a large series to make a survey. DESIGN AND METHODS: We analyzed records of patients diagnosed with pheochromocytomas in three geographically spread German referral centers between 2003 and 2012 (n=135). RESULTS: Eleven percent of the patients (ten women, five men) required in-hospital treatment on intensive care units (ICUs) due to complications caused by unsuspected pheochromocytomas. The main reasons for ICU admission were acute catecholamine induced Tako-Tsubo cardiomyopathy (n=4), myocardial infarction (n=2), acute pulmonary edema (n=2), cerebrovascular stroke (n=2), ischemic ileus (n=1), acute renal failure (n=2), and multi organ failure (n=1). One patient required extracorporeal membrane oxygenation due to a hypertensive crisis with lung edema occurring during delivery (n=1). Two patients died of refractory shock and pheochromocytomas were found postmortem. Two patients were treated by emergency surgery. Compared to pheochromocytoma patients without life-threatening events (n=120), patients with complications had a significant larger maximal tumor diameter (7.0 vs 4.5 cm, P<0.01), higher levels of catecholamines (20- vs ninefold upper limit of normal, P<0.01), and tended to be younger (42 vs 51 years, P=0.05). CONCLUSION: Although pheochromocytomas are rare, they are likely to be associated with a life-threatening situation. Clinicians have to be aware of these situations and perform a timely diagnosis.