Surgical Approaches to the Adrenal Gland

W, Barreto LO, Secaf A, Mermejo LM, Lucchesi FR, Tucci Jr. S, Elias Junior J, Molina CAF, Muglia VF. Histogram analysis in the differentiation between adrenal adenomas and pheochromocytomas: the value of a single measurement

Objective

To assess the diagnostic accuracy of histogram analysis on unenhanced computed tomography (CT) for differentiating between adrenal adenomas and pheochromocytomas (PCCs).

Materials and Methods

We retrospectively identified patients with proven PCCs who had undergone CT examinations between January 2009 and July 2019 at one of two institutions. For each PCC, we selected one or two adenomas diagnosed within two weeks of the date of diagnosis of the PCC. For each lesion, two readers scored the size, determined the mean attenuation, and generated a voxel histogram. The 10th percentile (P10) was obtained from the conventional histogram analysis, as well as being calculated with the following formula: P10 = mean attenuation - (1.282 × standard deviation). The mean attenuation threshold, histogram analysis (observed) P10, and calculated P10 (calcP10) were compared in terms of their diagnostic accuracy.

Results

We included 52 adenomas and 29 PCCs. The sensitivity, specificity, and accuracy of the mean attenuation threshold were 75.0%, 100.0%, and 82.5%, respectively, for reader 1, whereas they were 71.5%, 100.0%, and 81.5%, respectively, for reader 2. The sensitivity, specificity, and accuracy of the observed P10 and calcP10 were equal for both readers: 90.4%, 96.5%, and 92.6%, respectively, for reader 1; and 92.3%, 93.1%, and 92.6%, respectively, for reader 2. The increase in sensitivity was significant for both readers (p = 0.009 and p = 0.005, respectively).

Conclusion

For differentiating between adenomas and PCCs, the histogram analysis (observed P10 and calcP10) appears to outperform the mean attenuation threshold as a diagnostic criterion.

Minimally invasive techniques in benign and malignant adrenal tumors

Minimally invasive adrenalectomy has become the main treatment modality for most adrenal lesions. Both laparoscopic transabdominal and retroperitoneoscopic approaches are safe and feasible options, each with respective advantages, including better surgical outcomes, fewer complications, and faster recovery over open adrenalectomy. While open surgery remains a valid modality in treatment of adrenocortical cancer in the presence of some findings such as invasion, robotic platforms, and minimally invasive surgery have gained popularity as technology continues to evolve. Organ preservation during adrenalectomy is feasible in some conditions to prevent adrenal insufficiency. Ablative technologies are increasingly utilized in benign and malignant tumors, including the adrenal gland, with various outcomes. A multidisciplinary team, an experienced surgeon, and a high-volume center are recommended for any surgical approaches and management of adrenal lesions. This review article evaluated recent findings and current evidence on minimally invasive adrenalectomy.

Treatment of Primary Pigmented Nodular Adrenocortical Disease

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of adrenocorticotropin hormone (ACTH)-independent Cushing's syndrome (CS), which mainly occurs in children and young adults. Treatment options with proven clinical efficacy for PPNAD include adrenalectomy (bilateral or unilateral adrenalectomy) and drug treatment to control hypercortisolemia. Previously, the main treatment of PPNAD is bilateral adrenal resection and long-term hormone replacement after surgery. In recent years, cases reports suggest that unilateral or subtotal adrenal resection can also lead to long-term remission in some patients without the need for long-term hormone replacement therapy. Medications for hypercortisolemia, such as Ketoconazole, Metyrapone and Mitotane et.al, have been reported as a preoperative transition for in some patients with severe hypercortisolism. In addition, tryptophan hydroxylase inhibitor, COX2 inhibitor Celecoxib, somatostatin and other drugs targeting the possible pathogenic mechanisms of the disease are under study, which are expected to be applied to the clinical treatment of PPNAD in the future. In this review, we summarize the recent progress on treatment of PPNAD, in which options of surgical methods, research results of drugs acting on possible pathogenic mechanisms, and the management during gestation are described in order to provide new ideas for clinical treatment.

Adrenal Near-Infrared Autofluorescence

Context

Parathyroid tissue is one of the few tissues to have strong near-infrared (NIR) autofluorescence, which has been exploited to improve intraoperative parathyroid identification. The US Food and Drug Administration has approved 2 devices for this purpose. Adrenal glands can be difficult to distinguish from surrounding fat, an issue during total adrenalectomy.

Objective

We hypothesized adrenal tissue may also possess considerable NIR autofluorescence.

Methods

Resected patient adrenal specimens were examined after robotic adrenalectomy with an NIR camera intraoperatively. Patients did not receive fluorescent dye. Images were taken of both gross and sectioned specimens. Post hoc image analysis was performed with ImageJ software. Confocal microscopy was performed on selected tissues using immunofluorescence and hematoxylin-eosin staining.

Results

Resected tissue was examined from 22 patients undergoing surgery for pheochromocytomas (6), primary aldosteronism (3), adrenocorticotropin-independent hypercortisolism (10), and a growing or suspicious mass (3). Normal adrenal tissue demonstrated strong NIR autofluorescence. The intensity ratio compared to background (set as 1) for gross images was 2.03 ± 0.51 (P < .0001) compared to adjacent adipose of 1.24 ± 0.18. Autofluorescence from adrenal tumors was also detected at variable levels of intensity. Cortisol-producing tumors had the highest fluorescence ratio of 3.01 ± 0.41. Confocal imaging localized autofluorescence to the cytosol, with the highest intensity in the zona reticularis followed by the zona fasciculata.

Conclusion

Normal and abnormal adrenal tissues possess natural NIR autofluorescence. Highest autofluorescence levels were associated with cortisol-producing tumors. Confocal imaging demonstrated the highest intensity in the zona reticularis. NIR cameras may have the potential to improve identification of adrenal tissue during surgery.

Robotic resection for benign primary retroperitoneal tumors via the transperitoneal approach

BACKGROUND

Surgical resection is the primary treatment for benign primary retroperitoneal tumors. However, only a few studies have reported robotic resection for retroperitoneal tumors due to the low morbidity rate, and only a small fraction of retroperitoneal tumors are eligible for minimally invasive operations.

METHODS

A retrospective study enrolling 16 patients with benign primary retroperitoneal tumors between November 2016 and April 2020 was conducted to evaluate the efficacy of robotic resection for benign primary retroperitoneal tumors via the transperitoneal approach. Surgical skills were described in detail and operative experiences were summarized.

RESULTS

The operations were uneventfully performed without conversion in all the patients. The median operation time was 135 (120-180) min, and the median estimated blood loss was 25 (20-60) mL. The median duration of diet restoration was 2 (1-2) days and the median length of postoperative hospital stay was 6 (4-7) days. No serious intraoperative or postoperative complications occurred during the perioperative period.

CONCLUSIONS

Robotic resection via the transperitoneal approach is a feasible and safe procedure for highly selected patients with benign primary retroperitoneal tumors, with few postoperative complications and a rapid recovery.

Surgical approach to patients with primary aldosteronism

Primary hyperaldosteronism (PA) is one of the most common causes of hypertension that is amenable to surgical cure. Once a patient has a biochemical diagnosis of PA, workup should proceed with tumor lateralization to determine whether the patient has unilateral or bilateral disease. Tumor lateralization can be done with noninvasive imaging such as a CT or MRI. However, in older patients or in patients with non-lateralizing imaging, arteriovenous sampling (AVS) should be considered. If the patient has confirmed unilateral disease, options for surgical intervention include laparoscopic or, less commonly, open. Laparoscopic adrenalectomy for PA has been shown to be a safe and effective procedure that is associated with less morbidity compared to open adrenalectomy. Patients can either undergo a laparoscopic transabdominal adrenalectomy via a lateral (most common) or anterior approach or a retroperitoneoscopic adrenalectomy via a posterior approach. The majority of patients have complete biochemical success, defined as normalization of plasma aldosterone, renin and potassium levels and appropriate suppression with stimulation tests. Less than half of patients have complete clinical success, defined as normotensive with no antihypertensive medications. However, the majority of patients who do not have complete clinical success will have some improvement in their blood pressure and/or are able to decrease the number of antihypertensive medications that they require.

Surgical Indications and Techniques for Adrenalectomy

Indications for adrenalectomy are malignancy suspicion or malignant tumors, non-functional tumors with the risk of malignancy and functional adrenal tumors. Regardless of the size of functional tumors, they have surgical indications. The hormone-secreting adrenal tumors in which adrenalectomy is indicated are as follows: Cushing’s syndrome, arises from hypersecretion of glucocorticoids produced in fasciculata adrenal cortex, Conn’s syndrome, arises from an hypersecretion of aldosterone produced by glomerulosa adrenal cortex, and Pheochromocytomas that arise from adrenal medulla and produce catecholamines. Sometimes, bilateral adrenalectomy may be required in Cushing’s disease due to pituitary or ectopic ACTH secretion. Adenomas arise from the reticularis layer of the adrenal cortex, which rarely releases too much adrenal androgen and estrogen, may also develop and have an indication for adrenalectomy. Adrenal surgery can be performed by laparoscopic or open technique. Today, laparoscopic adrenalectomy is the gold standard treatment in selected patients. Laparoscopic adrenalectomy can be performed transperitoneally or retroperitoneoscopically. Both approaches have their advantages and disadvantages. In the selection of the surgery type, the experience and habits of the surgeon are also important, along with the patient’s characteristics. The most common type of surgery performed in the world is laparoscopic transabdominal lateral adrenalectomy, which most surgeons are more familiar with. The laparoscopic anterior transperitoneal approach is the least preferred laparoscopic method in adrenalectomy. Retroperitoneal laparoscopic adrenalectomy can be performed with a posterior or lateral approach. In addition to conventional laparoscopy, laparoscopic surgery is robot-assisted, which can be administered by transperitoneal or retroperitoneal approach. In addition, conventional or robot-assisted laparoscopic adrenalectomy can be performed transabdominally or retroperitoneally using the single-port method. Today, partial adrenalectomy can be performed using laparoscopic techniques in bilateral adrenal masses, hereditary diseases with the risk of developing multiple adrenal tumors, and solitary masses of the adrenal gland. Open surgery is indicated in the case of malignancy or suspected malignancy and large tumors when laparoscopic surgery is contraindicated. The risk of conversion to open surgery is low (approximately 5%). The open transperitoneal anterior approach is the most common open intervention, especially in large tumors with malignancy or suspected malignancy. This procedure can be performed using a midline incision, bilateral or unilateral subcostal incision, Makuuchi or modified Makuuchi incision. Thoracoabdominal incision may be required, especially in the removal of large malignant lesions as a block. The open retroperitoneal approach can be applied posteriorly or laterally.

Laparoscopic Approach to the Adrenal Masses: Single-Center Experience of Five Years

Objectives:

Currently, laparoscopic adrenalectomy is the gold standard technique for suitable patients with adrenal masses. In this study, we aimed to assess the postoperative results of patients who underwent laparoscopic adrenalectomy.

Methods:

Between January 2014 and October 2019, 76 cases were operated and retrospectively evaluated. Laparoscopic transabdominal adrenalectomy was applied to the patients. Demographic profiles, preoperative indications, intraoperative and postoperative complications, mortality and length of hospital stay were evaluated.

Results:

Seventy-six patients (30 male, 46 female) with a mean age of 47.2±11.7 (range 22-71) years underwent laparoscopic adrenalectomy. Thirty-nine of the patients had right; 33 of the patients had left adrenal masses. Three patients had bilateral adrenal cortical hyperplasia. One patient was operated for paraganglioma. Conversion to open adrenalectomy was observed in four patients (5.26%). Nine patients (11.8%) experienced intraoperative and postoperative complications. Intraoperative and postoperative complications were bleeding from spleen (2 cases) and upper pole of kidney (1 case), renal artery injury (1 case), bleeding from liver parenchyma (2 cases), ischemia of spleen and pancreas (1 case), small intestinal injury (1 case) and incisional hernia (1 case). The complication rate is acceptable and comparable with other studies in the literature.

Conclusion:

Laparoscopic adrenalectomy can be safely applied in suitable patients with acceptable complications and low conversion rates.

SURGICAL MANAGEMENT OF THE ADRENAL GLAND TUMORS - SINGLE CENTER EXPERIENCE

Context

Incidentally discovered solid adrenal tumors must be evaluated from two points of view: the risk of malignancy and the secretory feature.

Objective

Our aim was to evaluate the surgical technique option in relation with clinical and histopathologic features.

Design

We performed a retrospective study that included patients with adrenal gland tumors.

Subjects and methods

All patients were operated between 2012 and 2019 by the same surgical team in a single center.

Results

The batch included 102 patients with adrenal tumors operated through open surgery (OS, n=41) and laparoscopic surgery (LS, n=61). Tumor localization was especially on the right adrenal gland (n=52, 50.98%). Primary origin of the adrenal gland tumors was in 82 cases (80.39%) and a metastatic origin in 16 cases. Average dimension for surgical resected tumors was 4.02 cm (0.9-12 cm) for the LS group as compared to 7.22 cm (1.3-19 cm) for OS group with a predominant type of surgery represented by adrenalectomy and a conversion rate of 2.94%. The hospital stay was 7.22 days (5-12 days) in the LS group versus 12.72 days (6-57 days) in OS group with significant differences (p<0.01). Also, the postoperative recovery was significantly different (6.5 days versus 2.62 days, p<0.01).

Conclusion

Laparoscopic approach represents the gold standard in adrenal gland tumors less than five centimeters in size. Adrenalectomy is mostly performed by LS and adenoma is the most frequent histopathologic type, while pheochromocytoma is operated through OS. LS has a significantly reduced hospitalization and postoperative stay compared to OS.