Nebennierenresektion zum Erhalt der adrenokortikalen Funktion

[Personalized treatment of pheochromocytoma]

BACKGROUND

Pheochromocytoma is a rare but severe disease of the adrenal glands. The aim of this study is to present and discuss recent developments in the diagnosis and treatment of pheochromocytoma.

MATERIAL AND METHODS

A narrative review article based on the most recent literature is presented.

RESULTS AND DISCUSSION

The proportion of pheochromocytomas as tumors of adrenal origin is about 5% of incidentally discovered adrenal tumors. The classical symptomatic triad of headaches, sweating, and palpitations occurs in only about 20% of patients, while almost all patients show at least 1 of these symptoms. To diagnose pheochromocytoma, levels of free plasma metanephrines or alternatively, fractionated metanephrines in a 24‑h urine collection is required in a first step. In the second step an imaging procedure, computed tomography (CT) or magnetic resonance imaging (MRI), is performed to localize the adrenal tumor. Functional imaging is also recommended to preoperatively detect potential metastases. Genetic testing should always be offered during the course of treatment as 30-40% of pheochromocytomas are associated with genetic mutations. The dogma of preoperative alpha blockade is increasingly being questioned and has been controversially discussed in recent years. Minimally invasive removal of the adrenal tumor is the standard surgical procedure to cure patients with pheochromocytoma. The transabdominal and retroperitoneal laparoscopic approaches are considered equivalent. The choice of the minimally invasive procedure depends on the expertise and experience of the surgeon and should be tailored accordingly. Individualized and regular follow-up care is important after surgery.

Adrenal-sparing surgery: current concepts on a theme from the past

Adrenal insufficiency represents a debilitating condition which mandates lifelong steroid replacement and which is associated with significant long-term morbidity, due to either inadequate or excessive replacement. The concept of preserving healthy cortical tissue by means of partial adrenalectomy has evolved as a means of avoiding the detrimental consequences of adrenal insufficiency. The advent of advanced technology in adrenal surgery has greatly facilitated the performance of partial adrenalectomy, enabling utilization of this method in an increasing number of endocrine diseases. Hereditary pheochromocytoma, Conn's syndrome, Cushing's syndrome, and non-functional adrenal masses represent the current indications for partial adrenalectomy, although the specific circumstances under which adrenal-sparing surgery should be proposed are still debatable. Partial adrenalectomy can be achieved by all types of minimally invasive surgery. In the absence of randomized, prospective, controlled studies designed to compare laparoscopic, retroperitoneoscopic, and robot-assisted partial adrenalectomy, none of these techniques has as yet been proven to be the gold standard for adrenal-sparing surgery. Apart from indications for surgery, results of surgery, and different types of partial adrenalectomy, controversial topics addressed in this review article include technical aspects such as the volume of residual adrenal tissue needed, ligation of adrenal vein, and means of tumor identification. Discussion of these controversial topics represents an attempt to define the role of partial adrenalectomy in modern adrenal surgery.

[Surgery of adrenal diseases]

Incidentally discovered adrenal alterations should be separated into those without any clinical importance and adrenal diseases that have to be surgically or conservatively treated. Before operative treatment, in addition to the possible different functional activity of tumors, a differentiation must be made between sporadically arising singular or multiple adrenal tumors or nodular adrenal hyperplasia, adrenal tumors as part of a familial syndrome and metastases of other primary malignant tumors into the adrenal glands. Benign hormonally active adrenal tumors as well as questionable malignant tumors of the adrenal cortex are resected by minimally invasive techniques. For large malignant tumors infiltrating into surrounding tissues and tumors with proven lymph node metastases, the primarily open approach is indicated. Patients with adrenal diseases should always undergo an interdisciplinary assessment and in cases with clear indications for surgery, sometimes transferred to a center with experience in surgery and postoperative management of these patients.

Surgical therapy of adrenal tumors: guidelines from the German Association of Endocrine Surgeons (CAEK)

BACKGROUND AND AIMS

Previous guidelines addressing surgery of adrenal tumors required actualization in adaption of developments in the area. The present guideline aims to provide practical and qualified recommendations on an evidence-based level reviewing the prevalent literature for the surgical therapy of adrenal tumors referring to patients of all age groups in operative medicine who require adrenal surgery. It primarily addresses general and visceral surgeons but offers information for all medical doctors related to conservative, ambulatory or inpatient care, rehabilitation, and general practice as well as pediatrics. It extends to interested patients to improve the knowledge and participation in the decision-making process regarding indications and methods of management of adrenal tumors. Furthermore, it provides effective medical options for the surgical treatment of adrenal lesions and balances positive and negative effects. Specific clinical questions addressed refer to indication, diagnostic procedures, effective therapeutic alternatives to surgery, type and extent of surgery, and postoperative management and follow-up regime.

METHODS

A PubMed research using specific key words identified literature to be considered and was evaluated for evidence previous to a formal Delphi decision process that finalized consented recommendations in a multidisciplinary setting.

RESULTS

Overall, 12 general and 52 specific recommendations regarding surgery for adrenal tumors were generated and complementary comments provided.

CONCLUSION

Effective and balanced medical options for the surgical treatment of adrenal tumors are provided on evidence-base. Specific clinical questions regarding indication, diagnostic procedures, alternatives to and type as well as extent of surgery for adrenal tumors including postoperative management are addressed.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

Paraganglioma and phaeochromocytoma: from genetics to personalized medicine

Paragangliomas and phaeochromocytomas are neuroendocrine tumours whose pathogenesis and progression are very strongly influenced by genetics. A germline mutation in one of the susceptibility genes identified so far explains ∼40% of all cases; the remaining 60% are thought to be sporadic cases. At least one-third of these sporadic tumours contain a somatic mutation in a predisposing gene. Genetic testing, which is indicated in every patient, is guided by the clinical presentation as well as by the secretory phenotype and the immunohistochemical characterization of the tumours. The diagnosis of an inherited form drives clinical management and tumour surveillance. Different 'omics' profiling methods have provided a neat classification of these tumours in accordance with their genetic background. Transcriptomic studies have identified two main molecular pathways that underlie development of these tumours, one in which the hypoxic pathway is activated (cluster 1) and another in which the MAPK and mTOR (mammalian target of rapamycin) signalling pathways are activated (cluster 2). DNA methylation profiling has uncovered a hypermethylator phenotype in tumours related to SDHx genes (a group of genes comprising SDHA, SDHB, SDHC, SDHD and SDHAF2) and revealed that succinate acts as an oncometabolite, inhibiting 2-oxoglutarate-dependent dioxygenases, such as hypoxia-inducible factor prolyl-hydroxylases and histone and DNA demethylases. 'Omics' data have suggested new therapeutic targets for patients with a malignant tumour. In the near future, new 'omics'-based tests are likely to be transferred into clinical practice with the goal of establishing personalized medical management for affected patients.

[Function-preserving adrenalectomy for adrenal tumors]

Organ preserving resection (subtotal adrenalectomy) or adrenocortical autotransplantation can preserve adrenocortical stress capacity in bilateral adrenal surgery. After adrenocortical autotransplantation approximately 30% of patients do not need exogenous steroids. Organ preserving surgery avoids steroid supplementation in more than 80% of cases. After organ preserving resections in secondary or familial diseases, however, there is a relevant risk of recurrent disease: the rate of ipsilateral recurrence in familial pheochromocytoma is approximately 20% during a follow-up of 20 years. Routine administration of exogenous steroids should be avoided after subtotal adrenalectomy as functional restitution of the residual tissue might be disturbed. Approximately 80% of patients, however, present with impaired adrenocortical stress capacity directly after surgery. Within a few weeks some 80% of patients show a sufficient functional restitution of the adrenocortical stress capacity. Organ preserving adrenal surgery should be performed endoscopically. The adrenal remnant should not be devascularized; the adrenal vein, however, can be divided without functional consequences. About one third of a normal adrenal gland usually provides sufficient adrenocortical function.

Safe introduction of a new surgical technique: remote telementoring for posterior retroperitoneoscopic adrenalectomy

BACKGROUND

Posterior retroperitoneoscopic adrenalectomy (PRA) is a safe and effective approach to adrenalectomy, offering less pain and faster recovery than open or laparoscopic surgery. Although the popularity of PRA is increasing, few surgical centres have extensive experience with the procedure. The ideal approach to achieve proficiency with any new technique involves on-site observation of an experienced surgeon-mentor, followed by mentored hands-on experience of the surgeon-learner. However, it is not always feasible for a surgeon-mentor to offer on-site supervision to the surgeon-learner in his or her home institution. Advances in Internet applications have made remote telementoring a viable alternative to on-site mentoring in selected situations.

METHODS

We describe our experience in safely introducing PRA to Melbourne, Australia, where no highly experienced surgeon-mentors were available. A surgeon with experience of 12 PRA procedures attended from interstate, along with live telementoring via Skype video link by an overseas surgeon who had performed more than 200 PRA procedures, to mentor the surgeon-learner performing her first three cases.

RESULTS

The operating surgeon's first three PRA procedures proceeded uneventfully, with no complications, relatively short operative times and one-night hospital stays for all three patients. Twenty-two more have been performed since, without complications.

CONCLUSION

Remote telementoring is a safe and feasible way to assist surgeons in safely introducing new techniques. This strategy is particularly applicable in centres where no surgeon-mentor is locally available. It is important that the surgeon-learner has the skills and experience to complete the procedure using alternative techniques in the case of complications or technical failure.

Surgical management of adrenal tumors

Laparoscopic adrenalectomy has become the preferred method for removal of almost all adrenal tumors. An important component in selecting patients for this operation is a thorough understanding of the clinical presentation (mainly hypertension) and diagnostic workup for the full variety of functioning and nonfunctioning adrenal tumors including genetic evaluation when necessary (MEN2, VonHippel-Landau [VHL], type 1 neurofibromatosis [NF1], succinate dehydrogenase mutations [SDH], and MEN1). The indications and contraindications for a laparoscopic approach are discussed with regard to each tumor type. Relevant literature about partial and bilateral adrenalectomy is also summarized. Main areas of controversy are discussed including the size threshold to avoid risk of adrenal capsular effraction and the appropriateness of laparoscopic resection for suspected and known malignancy. This article presents recent data to help the surgeon make well-informed decisions and to optimize the operative approach for a wide variety of adrenal pathologies (secreting vs. non-secreting, benign vs. malignant tumors).