Original Article

Portless endoscopic adrenalectomy via a single minimal incision using a retroperitoneal approach: Experience with initial 30 cases

YUKIO KAGEYAMA, KAZUNORI KIHARA, TSUYOSHI KOBAYASHI,

SATORU KAWAKAMI, YASUHISA FUJII, HITOSHI MASUDA, MASATAKA YANO AND NOBUHIKO HYOCHI

Department of Urology and Reproductive Medicine, Graduate School Tokyo Medical and Dental University, Tokyo, Japan

Abstract

Aim: To assess the feasibility of portless endoscopic adrenalectomy via a single minimum incision that narrowly permits extraction of the specimen.

Methods: For 30 cases of adrenal tumor, portless endoscopic surgery through a single flank inci- sion (3-9 cm; mean, 5.6 cm) was performed without gas inflation or trocar port placement. All of the instruments used during surgery were reusable. The cases included primary aldosteronism (12), Cushing’s syndrome (6), preclinical Cushing’s syndrome (3), pheochromocytoma (1), non- functioning cortical adenoma (6), adrenocortical carcinoma (1) and adrenocortical hemorrhage (1). Results: Resection of the tumor was successfully completed, without complications, in all of the cases. Operative time was between 83 and 240 min (mean, 147 min). Estimated blood loss was 5- 470 mL (mean, 139 mL). None of the patients required blood transfusion. Postoperative course was uneventful. Wound pain was mild and walking and full oral feeding were resumed on the first and second postoperative day, respectively, in the majority of cases.

Conclusions: Adrenal tumors are good candidates for portless endoscopic surgery, which is safe, cost-effective, minimally invasive and matches favorably with laparoscopic surgery.

Key words adrenal gland tumors, adrenalectomy, endoscopy, minimally invasive, surgical procedure.

Introduction

Since laparoscopic techniques were introduced to adre- nal surgery between 1992 and 1993, laparoscopic adrenalectomy has been widely accepted as a minimally invasive method.1-4 With quick recovery, short hospital stay and less pain, the postoperative course of each patient has dramatically improved, compared with con- ventional open surgery. However, laparoscopic proce- dures are technically demanding for urologists who are not laparoscopic experts.5,6 In addition, gas inflation

Correspondence: Yukio Kageyama MD PhD, Department of Urology and Reproductive Medicine, Graduate School Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, 113-8519 Tokyo, Japan.

Email: kageyys.uro@tmd.ac.jp

Received 4 September 2003; accepted 17 February 2004.

might raise unfavorable complications, such as venous thrombosis, especially in elderly patients. Moreover, the operative cost of laparoscopic surgery is considerably high because of expensive disposable equipment.

We have developed a new surgical technique, portless endoscopic surgery (PLES), which combines advan- tages of both laparoscopic surgery and standard open operations.5 The main concept is to carry out operations through a single minimal incision that narrowly permits retrieval of the resected specimen. By identifying proper planes for cleavage under the guidance of both endos- copy and direct vision, surgeons can obtain an operating field large enough for manipulations deep in the wound. The working space is maintained using long retractors without gas inflation. Endoscopic view allows operators to identify fine structure of the target organs and sur- rounding tissues. All procedures are carried out retro- peritoneally and the peritoneal cavity is preserved intact. This practice avoids adhesions, which are

unfavorable for future abdominal surgery or might cause risk of intestinal obstruction. Moreover, costly dispos- able devices are not necessary, which provides a clear economic advantage to the technique.

We have been applying this PLES technique to most of the retroperitoneal surgery cases for urological dis- ease since 1998 and have experienced excellent out- comes.7-14 In the present study we report on the favorable results of PLES for the initial 30 cases of adrenal tumors.

Patients and methods

Patients

Thirty cases of adrenal tumor were treated by PLES between July 1998 and August 2003 (Table 1). The cases include primary aldosteronism (12), Cushing’s

syndrome (6), preclinical Cushing’s syndrome (3), pheochromocytoma (1), non-functioning cortical ade- noma (5), adrenocortical cancer (1), myelolipoma (1), and adrenocortical hemorrhage (1). Preoperative local- ization of the tumor was carried out using ultrasonog- raphy, computerized tomography (CT), magnetic resonance image (MRI), scintigraphy, or a combination of these. Fifteen tumors were on the right side and 18 were on the left. Maximum diameter of the tumor ranged from 0.5 to 6.5 cm (mean, 2.7 cm). Resection of the entire adrenal gland was carried out, except for three cases of primary aldosteronism (cortical adenoma), in which a part of the normal adrenal tissue was preserved.

Surgical technique

Patients were placed in the flank position over the break in the table. A small skin incision of approximately 5-cm length was made in the flank, running obliquely

Table 1 Patients' profiles and results of portless endoscopic adrenalectomy
TotalPrimary aldosteronismCushing's syndromet adenomaNon-functioningOthersţ
Patients' profiles
No. patients3012963
Average age§54 (22-79)57 (34-79)44 (22-61)67 (41-59)72 (67-79)
Sex (male/female)11/196/61/83/31/2
Side (right/left)12/184/86/31/51/2
Average tumor size on CT (cm)§2.7 (0.5-6.5)1.4 (0.5-2.5)2.7 (0.8-4.5)4.3 (2.5-6.5)7.5 (1.2-6)
Average BMI§24.1 (17.3-28.8)23.9 (18.1-26.5)23.7 (17.3-28.8)25.0 (23.0-28.4)24.8 (18.6-28.2)
Intraoperative data6.1 (4-8)5.9 (4-9)5.1 (4-6)
Average skin incision (cm)§5.6 (3-9)7 (3-6)
Average operative time (min)§147 (83-240)147 (113-185)138 (85-190)152 (83-240)163 (133-208)
Average blood139 (5-470)128 (5-470)128 (5-335)101 (5-262)290 (142-372)
loss (mL)§
TransfusionNoneNoneNoneNoneNone
ComplicationsNoneNoneNoneNoneNone
Postoperative data
Average first oral intake (days)§2 (1-3)1.7 (1-2)1.7 (1-3)1.7 (1-3)1.3 (1-2)
Average first walk (days)§1.1 (1-2)1 (1)1.1 (1-2)1.2 (1-2)1 (1)
Average hospital stay (days)§12 (6-27)10.4 (6-14)13 (7-25)12 (6-27)13 (9-17)
Average possible minimal hospital stay (days)§4.6 (3-8)4.3 (3-6)4.8 (3-7)5.7 (3-8)3.7 (3-4)
ComplicationsNoneNoneNoneNoneNone
Postoperative analgesics
None196553
Diclofenac sodium 25-75 mg116410

¡Includes three cases of preclinical Cushing’s syndrome. ¿ Pheochromocytoma, adrenocortical hemorrhage, and adrenocor- tical cancer. §Data are presented as mean (range). BMI, body mass index.

on the distal end of the 12th rib. The tip of the 12th rib was dissected off its bed and retroperitoneal space was opened by incising the transversalis and Gerota’s fascia. The 12th intercostal neurovascular bundle was spared. Gerota’s fascia was bluntly and widely pushed medially off the psoas muscle. The anterior aspect of Gerota’s fascia was then released from the peritoneum. At the beginning of the dissection along Gerota’s fascia, a 30° endoscope (5 mm or 4 mm in diameter) was introduced directly through the incision (Figs 1,2). Video monitors were attached to the endoscope so that the field could be viewed both through the incision and on the screen. The endoscope was held by one of the operators and moved on each occasion to the best position for viewing the operative fields. Subsequent procedures were carried out using a combination of video image and direct vision for the operator, and using only video image for the assistants. The upper pole of the kidney was then exposed and brought down caudally, which provided a

Fig. 1 Schematic presentation of the right adrenalectomy. The operation is performed from step 1-5. Step 1, dissec- tion along the posterior Gerota's fascia; Step 2, dissection along the anterior Gerota's fascia; Step 3, transection of the perinephric fat at the level of upper pole of the kidney; Step 4, dissection along the vena cava; and Step 5, transection of the adrenal vein. r, right; VC, vena cava.

r-adrenal gland

VC

5

3

4

1

2

r-kidney

working space that was broad enough for further proce- dures. Assistants kept the operating fields with PLES retractors or PLES spatulas (Figs 3d,e), positions of which were adjusted using the video monitor. After identifying the vena cava (for right side tumors) or left renal vein (for left side tumors), the central vein of the adrenal gland was identified, dissected, ligated and divided. After completing dissection of the rest of the attachment, the specimen was extracted through the incision. If malignancy was suspected, the tumor was entrapped in a vinyl bag (Fig. 1e). A drainage tube was introduced via the incision, which was closed layer by layer. A schematic view of the procedures required for a right adrenalectomy is presented in Fig. 4. In addition to standard operating instruments, we used PLES retrac- tors and PLES spatulas for maintaining working space, and a thread-pass, a knot slide (Kobayashi Medical Co., Japan), and a Maniceps (Mani Inc., Japan), which facil- itated ligation deep in the wound (Fig. 3). All of the instruments were reusable.

Results

All of the tumors were successfully resected without complications. As demonstrated in Table 1, the duration of the operation was between 83 and 240 min (mean, 147 min). Estimated blood loss was 5-470 mL (mean, 139 mL). None of the patients required blood transfu- sion. A case of pheochromocytoma (12 mm in diameter) was included in this series and the tumor was safely resected through a small incision (3 cm). Blood pressure was stable during the whole procedure. Postoperative course was uneventful in all cases. Wound pain was mild and postoperative analgesics were unnecessary in 19 cases. The remaining 11 patients were well managed by diclofenac sodium suppositories (25 mg to 75 mg in total). All patients, with the exception of three, were able to walk long distances (more than 100 m) on the day following surgery. The majority of the patients resumed full diet on the second postoperative day. Possible min- imal hospital stay (days required for full recovery when patients were on regular diet, without fever, free of any drainage tubes, free of analgesics and could walk long distances) was 3-8 days (mean, 4.6 days) after surgery. None of the patients showed recurrence of the tumor or persistence of hormonal abnormality during the obser- vation period of up to 5 years.

Discussion

In the present study, we have shown that adrenal tumors can be resected safely through a single minimum

Fig. 2 Portless endoscopic adrenalectomy in a case of non-functioning cortical adenoma. (A) right adrenal tumor (T) on a computer tomography (CT) scan (6 cm in diameter), (B) clipping of the adrenal vein, (C) a view from an overhead camera. An endoscope was placed at the caudal edge of the incision. (D) The extracted specimen and the incision, (E) extraction of the wrapped specimen through the incision, (F) the closed wound, a drainage tube and operator's fingers.

A

B

T.

T

VC

C

D

E

F

incision using PLES adrenalectomy. These results com- pare favorably with those of transperitoneal or retroperi- toneal laparoscopic adrenalectomy reported recently. As shown in Table 2, operative time, blood loss, and post- operative recovery of PLES were almost the same as those seen in laparoscopic surgery.15-17 We did not expe- rience intra- or postoperative complications in any of the 30 cases. Moreover, large tumors (>5 cm) were safely treatable by PLES (Fig. 1).

We have not experienced any difficulties in manipu- lation through an incision over the 12th rib. However, the 11th rib could be resected from the same incision if

surgeons think that the location of the adrenal gland is too deep or high for resection through the 12th rib.

The optimal magnification afforded by the 30° endoscope facilitates precise identification and dissec- tion of the adrenal glands. The combination of views, on monitor screens and direct vision, provides accu- rate information on the operating field, which might be crucial to avoid injury to surrounding organs. In the present study, approximately 30% of the proce- dures carried out depend on an endoscopic view. However, surgeons can select direct vision or endo- scopic view according to the situation of each case

Fig. 3 Surgical instruments for portless endoscopic sur- gery (PLES) adrenalectomy. (A) Thread-pass, which allows easy grasping of thread deep in the wound, (B) Maniceps, (C) knot slider, (D) PLES spatulas, (E) PLES retractors.

A

B

C

D

E

Fig. 4 Endoscopes for portless endoscopic surgery (PLES) adrenalectomy. (A) An irrigation system to clear the tip of the endoscope, (B) a 5-mm endoscope and its sheath, (C) a 4-mm endoscope.

A

B

C

and their skills, which makes PLES friendly to sur- geons without sufficient experience in laparoscopic surgery. Moreover, operators, anesthesiologists, nurses, and other paramedical staff can share the view of the operation, which might be important for timely man- agement of the patients’ condition.

As highlighted by other groups, complications of laparoscopic surgery are not negligible and are some- times serious.3,4 To avoid unfavorable events, urologists need to master different steps of the laparoscopic pro- cedures, which might require extensive learning and experience. In contrast, a short learning period is nec- essary for PLES, because it is based on the standard open surgery. The anatomic frame of reference, land- marks, and operative technique are not so different from those in standard open adrenalectomy. This advantage might prove particularly important because the inci- dence of adrenal tumors is relatively low, and might not be considered high enough for training urologists who are not familiar with laparoscopic techniques. PLES is based principally on the identification of proper planes for dissection. Surgeons with a good technical back- ground of open surgery might not experience difficulties performing PLES and will realize that the large incisions made in conventional open surgery are not

Table 2 Comparison of portless endoscopic surgery (PLES) and laparoscopic adrenalectomy
Transperitoneal15Laparoscopic adrenalectomyPLES (present series)
Retroperitoneal16Transperitoneal and retroperitoneal17
No. procedures1611157530
Average operative time (min)160118202147
Average blood loss (mL)9077148139
Transfusion (No. cases)3030
Average first oral intake (days)111.72
Average first walk (days)11-21.61.1
Average hospital stay (days)2.844.714.61
Complications (%)
Intraoperative03.4110
Postoperative3.712.1110

*Days required before the patient could be discharged from the hospital.

necessary for creating working space. It is advisable to start with a modification of standard open surgery, using an endoscope and tools for PLES, and then the size of the incision can be minimized step by step, according to the surgeon’s skill, in a short period of time.

In the present series, the operations were performed using a retroperitoneal approach and the peritoneal cav- ity was preserved intact. By doing this, surgeons can avoid intraperitoneal adhesion, which would be trouble- some if abdominal surgery was performed in the future, and can sometimes leads to intestinal obstruction. In addition, patients with previous open surgery of the upper abdominal regions are considered to be unsuitable for laparoscopic transperitoneal surgery. PLES can be applied safely to these cases, even with a previous his- tory of abdominal surgery, which might be rather com- mon in elderly patients.

Another advantage of PLES adrenalectomy is that the incision can be extended quickly and easily according to the situation. This allows operators to manage unfa- vorable events, including an extensive increase in blood pressure in pheochromocytoma, or unexpected bleeding from the vena cava. Although not included in the present series, two cases of large pheochromocytoma were also treated using PLES, via a minimal single incision. A transperitoneal approach was used in these patients, so that the adrenal vein could be reached immediately. In one of these cases, with a 10-cm tumor, we started the operation through an 8-cm subcostal incision that was extended step by step up to 15 cm, paying close atten- tion to patient’s blood pressure. The operation was suc- cessfully completed without any complications related to hypertensive events.

Finally, the low cost of operations might also be an advantage of the presented procedure, because most of the instruments used are reusable and are the same as those used in standard open surgery. Insertion of the

endoscope through the incision eliminates needs for additional skin incisions for the endoscope ports. Patients are able to benefit from the advantages of the minimally invasive operation at minimal cost. This is especially important in developing countries, where financial pressures are likely to discourage the use of endoscopic, minimally invasive operations.

In conclusion, PLES adrenalectomy is a minimally invasive method of treatment for adrenal tumors, with excellent postoperative recovery. We believe that PLES has distinct advantages in managing adrenal tumors in terms of safety, as well as flexibility and cost-effectiveness.

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