Posterior retroperitoneoscopic partial adrenalectomy using ultrasonic scalpel for aldosterone-producing adenoma

Silicon micromachined ultrasonic scalpel for the dissection and coagulation of tissue

This work presents a planar, longitudinal mode ultrasonic scalpel microfabricated from monocrystalline silicon wafers. Silicon was selected as the material for the ultrasonic horn due to its high speed of sound and thermal conductivity as well as its low density compared to commonly used titanium based alloys. Combined with a relatively high Young's modulus, a lighter, more efficient design for the ultrasonic scalpel can be implemented which, due to silicon batch manufacturing, can be fabricated at a lower cost. Transverse displacement of the piezoelectric actuators is coupled into the planar silicon structure and amplified by its horn-like geometry. Using finite element modeling and experimental displacement and velocity data as well as cutting tests, key design parameters have been identified that directly influence the power efficiency and robustness of the device as well as its ease of controllability when driven in resonance. Designs in which the full- and half-wave transverse modes of the transducer are matched or not matched to the natural frequencies of the piezoelectric actuators have been evaluated. The performance of the Si micromachined scalpels has been found to be comparable to existing commercial titanium based ultrasonic scalpels used in surgical operations for efficient dissection of tissue as well as coaptation and coagulation of tissue for hemostasis. Tip displacements (peak-to-peak) of the scalpels in the range of 10-50 μm with velocities ranging from 4 to 11 m/s have been achieved. The frequency of operation is in the range of 50-100 kHz depending on the transverse operating mode and the length of the scalpel. The cutting ability of the micromachined scalpels has been successfully demonstrated on chicken tissue.

Surgical management of adrenocortical tumours

The surgical treatment of adrenal tumours has evolved over the past century, as has our understanding of which hormones are secreted by the adrenal glands and what these hormones do. This article reviews the preoperative evaluation of patients with adrenal tumours that could be benign or malignant, including metastases. The biochemical evaluation of excess levels of hormones is discussed, as are imaging characteristics that differentiate benign tumours from malignant tumours. The options for surgical management are outlined, including the advantages and disadvantages of various open and laparoscopic approaches. The surgical management of adrenocortical carcinoma is specifically reviewed, including controversies in operative approaches as well as surgical management of invasive or recurrent disease.

Laparoscopic adrenalectomy for the management of benign and malignant adrenal tumors

Laparoscopic adrenalectomy has become the preferred approach for removal of the adrenal gland. Many published studies support the use of laparoscopic adrenalectomy, with comparisons to open adrenalectomy suggesting many advantages to laparoscopy, including less postoperative pain, shorter hospital stay and earlier return to work. Adrenalectomy is usually required for the removal of adrenal tumors causing excess hormone production or because a malignant adrenal tumor cannot be excluded. Current controversies include the appropriateness of laparoscopic adrenalectomy for large or malignant tumors, the role of partial adrenalectomy and the management of some conditions with uncertain natural history (such as subclinical hypercortisolism). With the increased use of sensitive cross-sectional imaging, the detection of clinically inapparent adrenal masses is likely to continue to increase. Due to the fact that malignancy cannot be excluded with certainty in some patients with cortical adenomas, it is expected that the rate of laparoscopic adrenalectomy will continue to increase.

Limitations of intraoperative adrenal remnant volume measurement in patients undergoing subtotal adrenalectomy

BACKGROUND

Recent studies have shown that a minimum of approximately one-third of one normal adrenal gland is required for sufficient adrenocortical stress capacity. Correlation between intraoperative measurement, determination of remnant size by computed tomography (CT), and adrenocortical stress capacity has not been examined so far.

METHODS

Twenty-two patients with familial pheochromocytoma (n=13), sporadic pheochromocytoma (n=3), and adrenocortical tumors (n=6) who underwent unilateral or bilateral subtotal adrenalectomy (STAE, 28 adrenal remnants) were prospectively studied. Patients were examined in a multi-slice CT to determine residual adrenal tissue and by ACTH test 4 days and 3 months postoperatively.

RESULTS

There was a slight significant correlation between intraoperative and CT calculated volumes (r=0.77; p<0.001). However, volumes assessed by CT were almost doubled compared with intraoperative determination (p<0.001). Although recovery of adrenal function could be observed, no significant changes of remnant volumes could be detected within 3 months. In patients with familial pheochromocytoma, there was a significant correlation between residual adrenal volume and stimulated cortisol levels (P<0.001). A distinct minimum of adrenal volume for intact adrenocortical stress capacity could not be exactly determined; however, in one patient with only 10% residual adrenal tissue intact stress capacity was found.

CONCLUSIONS

Residual adrenal tissue of approximately 10-15% offers intact stress capacity. However, an exact determination of the size of an adrenal remnant after STAE has limitations. CT gives larger volumes compared with intraoperative determination. For calculation of a volume-function correlation of residual adrenal tissue, in clinical practice, the determination of relative adrenal residual volume is acceptable.

Adrenal-preserving minimally invasive surgery: update on the current status of laparoscopic partial adrenalectomy

Adrenalectomy is the standard of care for hormonally active adrenal masses. In recent years, minimally invasive laparoscopic excision has become a preferred management option. As with advances in parenchymal-sparing renal surgery, investigators have begun to examine adrenal-sparing procedures to preserve functional adrenal tissue. This article reviews the recent literature and reports on intermediate results with laparoscopic partial adrenalectomy (LPA).

Laparoscopic partial adrenalectomy for aldosterone-producing adenomas with needlescopic instruments

INTRODUCTION

Laparoscopic total adrenalectomy is the treatment of choice for aldosterone-producing adenomas (APAs). There have not been many reports of laparoscopic partial adrenalectomy, although this procedure offers benefits to patients with suspected bilateral APAs or an APA in a solitary adrenal gland. We describe the feasibility of a novel technique of laparoscopic partial adrenalectomy for APA solely using 2-mm working instruments and a 5 to 10-mm telescope.

TECHNICAL CONSIDERATIONS

Six unilateral and two bilateral partial adrenalectomies were performed laparoscopically. Only one umbilical 12-mm port for the telescope and two (for left adenomas) or three (for right adenomas) subcostal 2-mm working ports were used. Hemostasis and transection of adrenal tissues were performed using a 2-mm mini-bipolar coagulator and 2-mm scissors.

RESULTS

All laparoscopic operations were successfully performed using only 2-mm working instruments and a 5 or 10-mm 30 degree telescope with no intraoperative or postoperative complications. Blood loss was minimal, and the operative times were comparable to those of previous reports. All patients had low pain scores, required minimal amounts of narcotics postoperatively, and reported excellent cosmetic results for the wounds. The pathologic examinations confirmed complete excision of all adenomas with intact capsules. The plasma aldosterone concentrations and renin activities returned to normal ranges postoperatively in all patients. At a mean follow-up of 25 months (range 13 to 48), 7 (87.5%) were cured of their hypertension and 1 had the hypertensive medications significantly reduced.

CONCLUSIONS

Laparoscopic partial adrenalectomy for APAs using 2-mm working instruments and a 5 to 10-mm telescope is a safe and effective treatment alternative.

Laparoscopic Adrenal Surgery: New Frontiers

After about 10 years of experience, laparoscopic adrenalectomy has become the gold standard for the treatment of adrenal lesions. Here, we describe the presenting features, imaging methods, and current surgical approaches to diseases of the adrenal gland. There is general agreement on the suitability of the laparoscopic approach for benign adrenal lesions, but controversy exists about using laparoscopy for suspected adrenal malignancy, metastasis, and partial adrenalectomy. This article reviews the literature on laparoscopic adrenalectomy. In particular, we focus our attention on the new surgical approaches to the gland. We evaluate the indications, operative techniques, and tools for partial adrenalectomy, and we discuss new surgical strategies such as cryosurgery and radiofrequency ablation.

Cryosurgery of the adrenal gland

Adrenalectomy has become the standard of care for the management of hormonally active adrenal masses. Minimally invasive adrenal-sparing surgical techniques have recently been introduced for the treatment of benign adrenal lesions, with the intent of complete excision or destruction. Cryosurgery is one such modality that is focused on reducing patient morbidity and hastening postoperative recovery, while preserving normal tissue. The emerging interest in cryosurgery is attributable to improved delivery systems and advances in radiologic imaging. However, questions remain about the risks and benefits of this technology for adrenal-sparing surgery in terms of safety and effective tissue destruction. We examine our experience and discuss our results with open and laparoscopic adrenal cryosurgery.

Extent of adrenalectomy for adrenal neoplasm: cortical sparing (subtotal) versus total adrenalectomy

The standard operation on adrenal neoplasias is a complete adrenalectomy. Accepted exceptions are bilateral inherited pheochromocytomas. In these cases, clinical and biochemical cure, as well as preservation of cortical function, can be achieved by a noncomplete adrenalectomy. In that procedure, at least one third of one gland has to be preserved. In unilateral adrenal tumors, partial resection has been used, especially in Conns adenomas, with early results comparable to those of total adrenalectomy. Because longterm results are still limited in hyperaldosteronism, final conclusions are not possible today.

Laparoscopic Reconstructive Urology

PURPOSE

Although laparoscopy has emerged as a feasible and effective alternative for a majority of open ablative abdominopelvic urological procedures, minimally invasive reconstruction has come to the forefront only recently. We present the current state of the art of laparoscopic reconstructive urology.

MATERIALS AND METHODS

We conducted an extensive MEDLINE search of purely laparoscopic surgery from 1976 through 2002. Based on the results, we divide clinical reconstructive laparoscopic procedures into 2 broad categories-established and evolving. Each category is further classified according to the organ involved-adrenal and kidney, ureter (evolving only), bladder and prostate, and miscellaneous. Clinical procedures were considered established if our literature review revealed any report of more than 100 patients, or reports from at least 5 different centers greater than 20 patients each. If these criteria were not met, the procedure was considered clinically evolving.

RESULTS

Laparoscopic reconstructive procedures such as pyeloplasty, radical prostatectomy and orchiopexy have achieved clinically established status. Laparoscopic bladder neck suspension, although reported in a significant number of cases, remains controversial because of its contradictory reported long-term success rates. Multiple additional laparoscopic reconstructive procedures have been performed in fewer numbers clinically with promising results.

CONCLUSIONS

Until recently, urological laparoscopic surgery primarily focused on ablative procedures, with success. Building on this initial experience, advanced and sophisticated reconstructive procedures of considerable technical complexity are increasingly being performed purely laparoscopically. It is anticipated that in the future laparoscopic surgery could increasingly evolve into a preferred approach for advanced and sophisticated urological reconstruction.

Adrenal-preserving minimally invasive surgery: the role of laparoscopic partial adrenalectomy, cryosurgery, and radiofrequency ablation of the adrenal gland

Adrenalectomy has become the standard of care for the management of hormonally active adrenal masses. Various surgical therapies have been proposed to excise completely or destroy these adrenal lesions, which may be benign or malignant. New minimally invasive, adrenal-sparing procedures have recently been introduced, among them laparoscopic partial adrenalectomy, cryosurgery, and radiofrequency ablation. These procedures focus on reducing patient morbidity and hastening postoperative recovery while preserving normal adrenal tissue. However, questions remain about the risks and benefits associated with routine application of minimally invasive therapies for adrenal-sparing surgery in terms of complete tumor extirpation. Clearly, more experience and longer follow-up is necessary to validate these procedures. Herein we describe the surgical techniques and early results of treatment with adrenal-sparing surgery.

Laparoscopic partial adrenalectomy in patients with aldosterone-producing adenomas: indications, technique, and results

OBJECTIVES

To report the indications, technique, and results in patients with primary hyperaldosteronism due to aldosterone-producing adrenal adenoma treated by laparoscopic partial adrenalectomy. Laparoscopy has become the technique of choice in adrenal surgery, but adrenalectomy is the standard procedure. Only a few studies have reported on partial adrenalectomy, and the indications and technique have not yet been clearly defined.

METHODS

From June 1995 to December 2001, 13 patients presented with hyperaldosteronism and a single adrenal adenoma (Conn's syndrome) and were treated with laparoscopic partial adrenalectomy. The mean age was 60 years, and the average tumor size was 2.1 cm in diameter. A transperitoneal approach was used in all patients, tumors were resected with safety margins by endoshears, and hemostasis was achieved by bipolar coagulation and finally by sealing with fibrin glue.

RESULTS

All procedures were finished laparoscopically, and no conversion was necessary. No major intraoperative or postoperative complication was observed. The histologic examination showed adenomas with negative surgical margins in all cases. Postoperative computed tomography revealed a normal blood supply for the remaining adrenal tissue. Blood pressure and aldosterone levels were unremarkable at follow-up, and no local recurrence was observed.

CONCLUSIONS

Laparoscopic partial adrenalectomy for aldosterone-producing adenomas is a minimally invasive procedure with a low complication rate. It provides the benefit of retaining functional tissue on the side of the affected adrenal gland. Therefore, we recommend laparoscopic partial adrenalectomy for patients with small, potentially benign, tumors of the adrenal gland, even with a healthy contralateral adrenal gland.

Laparoscopic bilateral partial adrenalectomy for pheochromocytoma

INTRODUCTION

To describe the technique of transperitoneal laparoscopic bilateral synchronous partial adrenalectomy in a patient with bilateral adrenal pheochromocytoma.

TECHNICAL CONSIDERATIONS

An 81-year-old woman with bilateral adrenal pheochromocytoma underwent bilateral laparoscopic partial adrenalectomy. A three-port transperitoneal approach was used for each side, with an additional port for liver retraction during right partial adrenalectomy. Laparoscopic flexible ultrasonography was invaluable for localizing the adrenal tumor and for precise planning of the line of excision. The right main adrenal vein was preserved. Dissection and enucleation of the adrenal tumor and parenchymal hemostasis was achieved effectively using a harmonic scalpel. The total operative time was 2 and 2.5 hours for the left and right adrenal gland, respectively. No major intraoperative hemodynamic instability was noted. The total blood loss was 150 mL, and the hospital stay was 4 days. Pathologic examination confirmed bilateral adrenal pheochromocytoma.

CONCLUSIONS

Laparoscopic partial adrenalectomy for pheochromocytoma is safe and technically feasible. Intraoperative ultrasonography is helpful to accurately plan resection of the tumor. If tumor location permits, the main adrenal vein should be preserved to ensure adequate vascularity for the adrenal remnant.