Surgical access to the adrenal gland: the quest for a "no visible scar" approach

Adrenal natural orifice transluminal endoscopic surgery (NOTES): a step too far?

Surgical approach to adrenal gland has evolved from open to minimally invasive surgery. With the advent of technology, multiple techniques and approaches are available in a surgeon's armamentarium today to deal with adrenal nodules that require surgical intervention. Each approach has its own advantages and disadvantages. The era of minimal invasive surgery has fuelled our quest for better cosmesis, faster recovery, early return to work and reduced hospital stay. While minimal invasive method is the preferred approach for most benign adrenal masses less than 6 cm, its application for large adrenal lesions as well as adrenocortical carcinoma is still debatable. Single incision minimal invasive procedures further try to reduce the incisions and wound morbidity. With the aim to completely remove visible scars and possibly reduced morbidity, the concept of natural orifice transluminal endoscopic surgery (NOTES) has been proposed by some surgeons as well as interventional gastroenterologist. In NOTES, the peritoneal cavity is accessed through a hollow viscus to perform therapeutic as well as diagnostic procedures. While the theoretical advantages of scar less surgery and its advantages sound encouraging, the precise indications and its potential advantages for adrenal pathologies is yet to be defined. It should in no way, compromise our goal of safe patient surgery and outcomes.

Pure retroperitoneal natural orifice translumenal endoscopic surgery (NOTES) transvaginal nephrectomy using standard laparoscopic instruments: a safety and feasibility study in a porcine model

Background

Among the different organs used for NOTES (natural orifice translumenal endoscopic surgery) technique, the transvaginal approach may be the optimal choice because of a simple and secure closure of colpotomy site. Pure and hybrid NOTES transvaginal operations were routinely performed via transperitoneal access. In this study, we investigate the safety and feasibility of pure retroperitoneal natural orifice translumenal endoscopic surgery (NOTES) transvaginal nephrectomy using conventional laparoscopic techniques in a porcine model.

Methods

Six female pigs, weighing an average of 30 kg, were used in this study. Under general anesthesia, pure retroperitoneal NOTES transvaginal nephrectomy was conducted using standard laparoscopic instruments. Posterolateral colpotomy was performed, and the incision was enlarged laterally using blunt dissection and pneumatic dilation. A single-port device was inserted to construct the operative channel. The retroperitoneal space was created using sharp and blunt dissection under endoscopic guidance up to the level of the kidney. Dissection and removal of the kidney were performed according to standard surgical procedure, and the colpotomy site was closed using interrupted sutures. The survival and complications were observed 1 week postoperatively.

Results

Our results showed that two cases failed because of peritoneal rupture. One case was successful, but required the assistance of an extra 5 mm laparoscopic trocar inserted in the flank. Three cases of pure retroperitoneal NOTES transvaginal nephrectomy were completed, and survived 1 week after the operation. In these three cases, no intra- or postoperative complications were observed.

Conclusions

All findings confirmed the safety and feasibility of the retroperitoneal pure retroperitoneal NOTES transvaginal nephrectomy using standard laparoscopic instruments, which suggested the possibility of clinical application in human beings in the future.

On the suitability of Thiel cadavers for natural orifice transluminal endoscopic surgery (NOTES): surgical training, feasibility studies, and anatomical education

BACKGROUND

Surgical training in virtual, animal and cadaver models is essential for minimally invasive surgery. Thiel cadavers are suitable for laparoscopy, but there are few data about the use of embalmed (Tutsch method) and slightly embalmed (Thiel method) cadavers in procedures of Natural Orifice Transluminal Endoscopic Surgery (NOTES), which are usually developed and learned on swine models and fresh frozen cadavers. The aim of this study was thus to assess the use of these cadavers for NOTES approaches.

METHODS

The following surgical procedures were evaluated: transanal total mesorectal excision (four cadavers: one Tutsch, two Thiel, one fresh frozen), transanal ileorectal bypass (five cadavers: one Tutsch, three Thiel, one fresh frozen), and transvaginal appendectomy (two Tutsch cadaver).

RESULTS

The Thiel method ensured tissue flexibility and consistency suitable for performing the above surgical procedures with good results and without complications, with only a small increase in rigidity with respect to fresh specimens. Cadavers embalmed with higher formalin concentrations (Tutsch method) were more difficult to use, due to high tissue rigidity and resistance of the abdominal wall to pneumoperitoneum, although NOTES accesses were possible.

CONCLUSIONS

Thiel cadavers are suitable for transanal/transrectal and transvaginal NOTES approaches, for training surgical residents/specialists and also for surgical research. In minimally invasive surgery (and particularly in NOTES), integration between cadaver (fresh frozen and/or Thiel) and animal models would represent the gold standard, allowing guaranteed knowledge of and respect for human surgical anatomy and correct management of surgery on living subjects. NOTES approaches to human cadavers may also be proposed for the anatomical education of medical students.

Retroperitoneoscopic adrenalectomy in pheochromocytoma

Since the first laparoscopic adrenalectomy, the technique has evolved and it has become the standard of care for many adrenal diseases, including pheochromocytoma. Two laparoscopic accesses to the adrenal have been developed: transperitoneal and retroperitoneal. Retroperitoneoscopic adrenalectomy may be recommended for the treatment of pheochromocytoma with the same peri-operative outcomes of the transperitoneal approach because it allows direct access to the adrenal glands without increasing the operative risks. Although technically more demanding than the transperitoneal approach, retroperitoneoscopy can shorten the mean operative time, which is critical for cases with pheochromocytoma where minimizing the potential for intra-operative hemodynamic changes is essential. Blood loss and the convalescence time can be also shortened by this approach. There is no absolute indication for either the transperitoneal or retroperitoneal approach; however, the latter procedure may be the best option for patients who have undergone previous abdominal surgery and obese patients. Also, retroperitoneoscopic adrenalectomy is a good alternative for treating cases with inherited pheochromocytomas, such as multiple endocrine neoplasia type 2A, in which the pheochromocytoma is highly prevalent and frequently occurs bilaterally.

Upper tract urologic LaparoEndoscopic Single-Site surgery

LaparoEndoscopic Single-Site (LESS) surgery has been developed as an extension of conventional laparoscopy to provide a minimally invasive option with fewer incisions, minimizing scars and potentially improving postoperative convalescence. These techniques have been adopted in the practice of urologic surgery, and largely employed to date for upper tract surgery by urologists in specialized centers with advanced laparoscopic practices. Herein, we review the current experience with upper tract urologic LESS surgery.

Critical analysis of hot topics in NOTES

Natural orifice transluminal endoscopic surgery (NOTES) has gained a great deal of attention from gastroenterologists and surgeons all over the world since its introduction in 2000. The field of NOTES has advanced tremendously since that time and exciting and well-designed research has been reported. Both randomized controlled trials and results from large national and international registries have been published. Many experimental and clinical studies have discussed transesophageal, transgastric, transvaginal and transrectal access for a variety of NOTES procedures. Transvaginal access has been the most frequently reported NOTES access route in clinical trials. When suitable instruments become available, a true comparison of NOTES with current laparoscopic approaches can be realized.

The challenges with NOTES retroperitoneal access in humans

BACKGROUND

Animal studies have supported natural orifice transluminal endoscopic surgery (NOTES) retroperitoneal access. NOTES also may offer unique retroperitoneal access in humans.

OBJECTIVES

This study was designed to assess the feasibility of endoscopic transgastric and transrectal retroperitoneal access in a cadaver model using prone and supine positioning, and to compare NOTES retroperitoneal examination with endoscopic ultrasound.

METHODS

Using a multidisciplinary team, this institutional review board-approved study evaluated transgastric and transrectal retroperitoneal examination in six cadavers (3 male, 3 female; body mass index range, 25-37 kg/m(2)). Endoscopic ultrasound retroperitoneal examination preceded NOTES access. Transgastric Access: Using a prototype dual channel endoscope, a needle knife gastrotomy was created on the preantral posterior gastric wall. Retroperitoneal examination specifically targeted the pancreas and surrounding structures with the cadaver supine and prone. Transrectal Access: Using the same endoscope, a posterior needle knife rectotomy distal to the upper valve of Houston provided extraluminal access. Retroperitoneal examination proceeded with the cadaver prone and supine. Open dissection followed procedure completion.

RESULTS

Access into the retroperitoneum succeeded at all sites. Significant challenges locating identifiable landmarks were faced-mostly transrectal and improved transgastric prone. All cadavers, despite body mass index or sex, had significant retroperitoneal adipose tissue limiting the endoscopic view.

CONCLUSIONS

Although porcine studies have highlighted successful NOTES retroperitoneal procedures, the abundant human retroperitoneal adipose tissue challenged the translation of porcine research to humans. Additionally, although access to the retroperitoneal space and dissection within this space were accomplished easily, the appearance of cadaveric tissue and lack of blood flow made confident landmark identification impossible. Further study should continue in this area and focus on confident landmark identification for directed dissection. In a cadaveric model, this would best be improved by pre-NOTES anatomic marking or active perfusion of vasculature along with consideration of direct entry into the retroperitoneum from a targeted intraperitoneal site in clinical patients.

Natural orifice translumenal endoscopic surgery

PURPOSE OF REVIEW

Since its introduction in 2000, natural orifice translumenal endoscopic surgery (NOTES) has gained a great deal of attention from gastroenterologists and surgeons all over the world. In this article, we will review the progress in the field of NOTES and present the latest publications that provide some answers and solutions to the barriers suggested by the Natural Orifice Surgery Consortium for Assessment and Research white paper.

RECENT FINDINGS

Because of the first human NOTES procedure by Rao and Reddy, more pioneering procedures, including transgastric and transvaginal cholecystectomies, appendectomies, and hernia repairs, have been performed. Although NOTES researchers continue to experiment with new innovative equipment and procedures in the lab, more structured work, including randomized controlled trials, has been published.

SUMMARY

In the last several years, there has been growing interest in NOTES, which has translated into exciting animal research work and publication of randomized controlled trials. Additionally, preliminary NOTES human procedures have been successfully performed. When suitable instruments become available, the subsequent step should be comparing NOTES with current laparoscopic approaches. Superiority or even equality of NOTES to laparoscopic surgery would be the best argument for advancing and integrating implementation into clinical practice.

Transgastric cholecystectomy: From the laboratory to clinical implementation

After the first report by Kalloo et al on transgastric peritoneoscopy in pigs, it rapidly became apparent that there was no room for an under-evaluated concept and blind adoption of an appealing (r)evolution in minimal access surgery. Systematic experimental work became mandatory before any translation to the clinical setting. Choice and management of the access site, techniques of dissection, exposure, retraction and tissue approximation-sealing were the basics that needed to be evaluated before considering any surgical procedure or study of the relevance of natural orifice transluminal endoscopic surgery (NOTES). After several years of testing in experimental labs, the revolutionary concept of NOTES, is now progressively being experimented on in clinical settings. In this paper the authors analyse the challenges, limitations and solutions to assess how to move from the lab to clinical implementation of transgastric endoscopic cholecystectomy.

NOTES new frontier: Natural orifice approach to retroperitoneal disease

AIM: To develop a pure transvaginal access to the retroperitoneum, that is simple, reproducible and uses endoscopic material available on the market.

METHODS: From February 2008 to April 2009, 31 pigs were operated on, with 17 as an acute experiment and 14 with a survival protocol. The animals were placed in a supine position and a 12-mm double-channel endoscope (Karl Storz™, Tuttlingen) was used for vision and dissection. During the same time period, the access experiment was reproduced on 3 human cadavers using material similar to that used in the animal model.

RESULTS: In the animal model, 37 interventions were done on the kidney, adrenal gland and pancreas. The mean time to fashion the access was 10 min (range 5 to 20 min). No intraoperative death was observed. Two major (5%) intraoperative complications occurred: one hemorrhage on the aorta and one tearing of the right renal vein. Peritoneal laceration was encountered in 5 cases without impairing the planned task. In the survival group, good clinical outcome was observed at a mean follow-up of 3 wk (range 2 to 6 wk). In the 3 cadavers, access was performed correctly. The mean time to fashion the access was 52 min (range 40 to 60 min). All the anatomical landmarks described in the pig model were clearly identified in the same sequence.

CONCLUSION: A retroperitoneal natural orifice translumenal surgical transvaginal approach is feasible in both animal and human models and allows performance of a large panel of interventions.

[Laparoscopic adrenalectomy: presentation of 43 cases]

INTRODUCTION

The aim of the study was to present and analyse our experience in laparoscopic adrenalectomy (LA).

MATERIALS AND METHODS

Descriptive and retrospective study including LA performed over 8 years, between 2000 and 2008 in our hospital.

RESULTS

A total of 43 LA were performed to 41 patients using a transperitoneal lateral approach. Indications for adrenalectomy included hyperaldosteronism (19), non-functioning adenoma (8), phaeochromocytoma (6), Cushing's syndrome (6), metastasis (3) and adrenal primary tumour (1). Median postoperative hospital stay was 3 days and the median size of the masses was 30mm (range: 4-155mm) Complications occurred in 3 patients (2 respiratory infections, and 1 intraoperative bleeding). There was no mortality. Only one case needed conversion to open adrenalectomy; no patients required reintervention.

CONCLUSION

Laparoscopic adrenalectomy is a safe and effective method in the treatment of adrenal masses and it can be performed with minimal risk and morbidity.