Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1382_Библиотеки_им_академика_М_И_Перельмана.pdf
“This page left intentionally blank.”
34
Laparoscopic Retroperitoneal Adrenalectomy
Shamly V. Dhiman and James A. Lee
Introduction
Laparoscopic adrenalectomy haslargely replaced
open adrenalectomy as the preferred method for
resection of most adrenal tumors. Adrenocortical cancer and malignant pheochromocytoma
remain relative contraindications to this rule.
Over the years, many techniques forlaparoscopic
adrenalectomy have been developed, including
multiple variations on the transabdominal and
retroperitoneal approaches (i.e., lateral, supine,
prone). The lateral transabdominal approach
has become the most widely used technique
for laparoscopic adrenalectomy due to the
familiar view and well-defined anatomical landmarks while the retroperitoneal approaches fell
by the wayside at most centers. However, in
recent years a number of advances in the posterior retroperitoneal technique have led to a
renaissance in the laparoscopic retroperitoneal
approach for selected patients.
Since the first case report of successful retroperitoneal adrenalectomy in 1994, the technique of this operation has been significantly
improved and refined to the point where some
authors consider it superior to the lateral
transabdominal approach for selected patients
[1]. In fact, some institutions use the retroperitoneal approach as the preferred method of
adrenalectomy for most adrenal tumors. In
the largest series to date, Walz et al. performed
560 adrenalectomies via this approach in
tumors that spanned the gamut of pathology
andsizeupto10cm[2].Intheearlyphasesof
development, the main problems with the retroperitoneal approach included (1) difficulty
creating an adequate working space and (2)
lack of traditional landmarks. Many of these
issues were solved by optimizing the patient
positioning, increasing the retroperitoneal
insufflation pressure, and codifying the
approach to dissection [3–5]. In particular,
the liberal use of insufflation pressures of
12–30 mm Hg have drastically increased the
size of the working space and made the operation much simpler.
Benefits of Retroperitoneal
Adrenalectomy (Compared to
Transabdominal Adrenalectomy)
Reduced Operating Times
Many series have documented that operative
times for laparoscopic adrenalectomy by any
method have reached parity with open operative
times and in most cases have decreased [7–9].
While the duration of operation differs between
the left and the right side, the average operative
time for a lateral transabdominal approach is
approximately 80–120 min. In the largest series
of retroperitoneal adrenalectomies, the average
operative time was 67 min [2]. When the analysis was limited to the most recent operations,
J.G.H. Hubbard et al. (eds.), Endocrine Surgery, Springer Specialist Surgery Series,
DOI 10.1007/978-1-84628-881-4_34, Ó Springer-Verlag London Limited 2009
451
452
ENDOCRINE SURGERY
this operative time dropped even further to
40 min, reflecting the steep learning curve of
the early years of development. Much of this
decrease in operative time between the two
methods is due to the direct access to the adrenal gland in the retroperitoneal technique. With
the transabdominal technique, much of the
operation is spent mobilizing the abdominal
viscera (i.e., liver, spleen, pancreas) just to
expose the adrenal gland. In the retroperitoneal
approach, the kidney, adrenal gland, and periadrenal fat are immediately in view with little
dissection. In addition, one of the most timeconsuming parts of the procedure is proper
patient positioning. For cases of bilateral adrenalectomy, obviating the need to ‘‘flip’’ the
patient into the contralateral decubitus position
in the lateral transabdominal approach further
reduces operating room time. With the retroperitoneal approach, the patient need only be
shifted toward the contralateral side of the table.
Avoidance of Intraabdominal Adhesions
and Irradiated Fields
Laparoscopic lateral transabdominal adrenalectomy is safe and feasible to perform in
patients who have had prior abdominal surgery.
However, in a large multicenter retrospective
analysis there was a trend toward longer operative times in patients with previous upper
abdominal surgery [6]. The retroperitoneal
technique eliminates the need for lysis of
intraabdominal adhesions, further reducing
operative time. With the exception of certain
urologic procedures, the retroperitoneal planes
are seldom affected by previous operations. The
same benefit applies for avoiding the desmoplastic reaction in previously irradiated fields.
Potential Decrease in Postoperative Pain
and Incisional Hernia
In general, laparoscopic adrenalectomy has
reduced the incidence of complications, length
of stay, and severity of postoperative pain when
compared to open adrenalectomy [10, 11]. Some
authors have suggested that retroperitoneal
adrenalectomy yield further decreases in postoperative pain then even the laparoscopic transabdominal approach, although this has yet to be
proven in a randomized controlled clinical trial
[2, 12]. In addition, incisional hernia rates in
laparoscopic transabdominal adrenalectomy
depend largely on the pathology and whether or
not the surgeon enlarges the fascia at the site of
extraction. However, incisional hernias are
almost nonexistent with the retroperitoneal
approach since the kidney occupies the space
throughwhich potential hernias would encroach.
Improved Hemostasis
One of the side benefits of insufflation in a small,
closed space is that the increased pressure leads
to improved hemostasis. The small venules and
arterioles associated with the adrenal gland typically ‘‘auto-tamponade’’ and seal with insufflation pressures alone at pressures of 12–20 mm
HG. If there is recalcitrant bleeding, often
increasing the insufflation pressure to
25–30 mm Hg will effect hemostasis. In one
large series, when a caval injury or adrenal vein
injury occurred, increasing the insufflation pressure allowed for hemostasis until a definitive
solution was accomplished. Of note, there were
no instances of gas embolism in this series [6].
Disadvantages of Retroperitoneal
Adrenalectomy (Compared with
Transabdominal Adrenalectomy)
The main weaknesses of the retroperitoneal
approach include a small working space, a perceived lack of anatomic landmarks, and the
inability to explore the rest of the abdominal
cavity. As mentioned previously, using increased
insufflation pressures and proper positioning of
the patient help to enlarge the limited working
space. However, judicious selection of patients
based on tumor size is critical. Tumors greater
than 7 cm in size should be approached through
a transabdominal approach. Perhaps the major
drawback for the surgeon just learning the technique of retroperitoneal adrenalectomy is the
lack of familiar landmarks, such as the spleen,
pancreas,and liver. However, once the surgeon is
oriented to the layout of the retroperitoneal
space, finding the critical landmarks is straightforward. The retroperitoneal space is bounded
by the peritoneum laterally, paraspinous muscle
medially, ribcage posteriorly (i.e., away from the
table), and kidney/adrenal gland/peritoneum
anteriorly (i.e., toward the table).
453
LAPAROSCOPIC RETROPERITONEAL ADRENALECTOMY
Indications and Contraindications
The indications for laparoscopic retroperitoneal
adrenalectomy are generally the same as for
laparoscopic transabdominal adrenalectomy.
Almost any tumor that can be removed via a
transabdominal approach can be removed
through the retroperitoneal approach, including pheochromocytoma and adrenal metastases
[2, 13–16]. Relative contraindications to a retroperitoneal approach include:
1) Tumors larger than 7 cm – it can be difficult
to create an adequate working space with a
tumor this large
2) Body mass index >45 – in morbidly obese
patients, it is often difficult to create enough
room between the table and the patient to
accommodate the large pannus. In these
situations, the pannus and intraabdominal
fat push onthe retroperitoneal space, collapsing it.
3) Increased ocular pressures – prone position-
ing can increase the intraocular and intraorbital pressures and cause pressure on the
optic nerve and in extreme cases blindness.
This effect is typically only seen in operations lasting many, many hours.
4) Need to explore the rest of the abdomen
(such as examining the liver for metastases).
Whether or not suspected adrenocortical cancers or malignant pheochromocytoma should
be removed laparoscopically by any means is a
controversial topic. With increased experience
and laparoscopic skill, the once inviolate rule of
removing adrenal cancers through an open incision has been challenged. As with other areas
where laparoscopy seems to improve oncologic
outcomes, laparoscopic resection of primary
adrenal cancers may become the norm. One of
the few remaining absolute contraindications
for abdominal laparoscopy is a disorder that
precludes abdominal insufflation (e.g., severe
lung or cardiac disease). However, with the limited intrusion on the diaphragm that results
from retroperitoneal insufflation, this limitation
is only relatively applicable to the retroperitoneal technique. Certainly contraindications to
increased venous pressure or decreased venous
return (such as cranial hypertension) still apply
for retroperitoneal right adrenalectomy since
the inferior vena cava is compressed, but may
not applyto retroperitoneal left adrenalectomy.
Giebler et al. studied the hemodynamic
changes with retroperitoneal insufflation and
found that hemodynamic changes do occur
(increased central venous pressure, cardiac
output,meanarterialpressure,andmeanpulmonary arterial pressure), but that these
changes had no apparent adverse effects [17].
The one absolute contraindication for laparoscopic retroperitoneal adrenalectomy is uncorrectable coagulopathy.
Technique
Patient Positioning
The patient is first intubated on a stretcher
and intravenous access and monitoring is
obtained as appropriate. A urinary catheter
is inserted. Two noncompressible bolsters
are placed on the operating table of sufficient
size to allow the pannus to lay elevated off
the table. One bolster is placed at the joint in
the bed where the lower extremity section
meets the lower torso section. The hips will
rest on this bolster. The second bolster is
placed approximately at the level of the
lower ribcage. Leg extensions are secured to
the table. The patient is then placed in the
prone position on the operating table with
the hips and chest on the appropriate bolster. The patient should be flush to the side
of the table. At this point, it is important to
insure that the pannus is elevated off the
table and that the bolster does not compress
the breasts. The bed is then flexed at the
junction of the upper and lower torso sections (approximately 308)andatthejunction
of the lower torso and lower extremity sections (approximately 458) to position the
lower back in a completely horizontal position. It is crucial to have the lower back in a
completely neutral position to allow for full
expansion of the retroperitoneal space. The
leg extensions are then positioned horizontal
to the floor to help prevent the patient from
slipping caudally on the table. The arms are
flexed at the elbows. All pressure points are
padded generously and the skin is protected
while the patient is appropriately secured in
place (see Fig. 34.1).
454
ENDOCRINE SURGERY
Fig. 34.1. Patient positioning.
Port Placement
Three ports are placed in a rough line based on
the inferior costal margin. The middle most port
is placed just lateral to the paraspinous muscles
and the lateral port is placed as far laterally as
possible. These ports are 5-mm ports that are
placed under direct palpation. The middle port
lies halfway between the lateral and the medial
ports and is the first port placed. This port is
placed by first making a 1.5-cm incision just
inferior to the costal margin and then bluntly
entering the retroperitoneal space with a Metzenbaum scissor. Spreading with the scissors
expands this site of entry. Using a finger, the
retroperitoneal space is then developed bluntly
both medially and laterally so that the remaining ports may be placed safely using direct palpation. The medial port incision is placed
approximately 4–5 cm caudal to the inferior
margin of rib 12. The port is then placed into
the retroperitoneal space on a bias or angle just
inferior to rib 12. A 10-mm port with a ‘‘donut’’
balloon is placed into the middle port site.
Dissection of the Retroperitoneal Space
After insufflation to a pressure of 15 mm Hg, the
camera is introduced into the medial port and
using a grasper in the lateral port, the Gerota’s
fascia is entered bluntly. Once Gerota’s fascia is
entered, the peri-adrenal and peri-renal fat
should be swept anteriorly (i.e., toward the
table) staying in the filmy posterior attachments. This dissection is carried laterally to
reveal the peritoneum, medially to uncover the
paraspinous muscles, and toward the apex
where the paraspinous muscle and peritoneum
meet. Once the medial port site is free of surrounding tissue, the camera is moved to this
port and another instrument is introduced into
the medial port. At this point, the superior pole
of the kidney is identified. Starting laterally, the
connections between the adrenal gland and the
superior pole of the kidney are divided. This
dissection is carried toward the renal hilum
and along the cranial half of the anterior surface
of the kidney so that the kidney may be
retracted inferiorly and medially. This retraction of the kidney facilitates identification and
ligation of the adrenal vein. During the course of
this dissection, inferior adrenal arteries may be
encountered and should be ligated with a purpose-made sealing device or electrocautery if
the vessel is small enough. The filmy plane
between the adrenal gland and the paraspinous
muscles medially should be dissected with
455
LAPAROSCOPIC RETROPERITONEAL ADRENALECTOMY
careful blunt and sharp dissection to expose the
inferior phrenic vein on the left and the inferior
vena cava on the right. During the course of this
dissection, middle and superior adrenal arteries
may be encountered and should also be ligated
and divided.
Identification and Ligation of the Adrenal Vein
Right Adrenalectomy (Fig. 34.2)
Once the inferior vena cava is identified, the
adrenal vein typically enters the adrenal gland
at about the midpoint and on its anterior surface (i.e., closer to the table). The adrenal vein
may be ligated and divided between clips or
with a purpose-made sealing device.
Fig. 34.3. Left adrenal vein anatomy.
Left Adrenalectomy (Fig. 34.3)
The inferior phrenic vein may be traced toward
the renal hilum to identify the adrenal vein.
Alternatively, the left adrenal vein may be identified from lateral to medial as the kidney is
rotated inferiorly and medially. The left adrenal
gland often has a tongue of tissue extending
along or caudal to the adrenal vein. It is important to fully dissect out this extension of the
gland. The left adrenal vein may be divided in
the same manner as the right adrenal vein. The
phrenic vein can usually be left intact.
Removal of the Adrenal Gland
Once the adrenal vein is ligated, the adrenal
gland may be separated from the filmy
attachments to the peritoneum using a combination of blunt and sharp dissection. Staying in
this avascular plane facilitates removal of all the
periadrenal fat and avoids rupture of the capsule. The specimen is placed in an extraction
bag and removed. The 10-mm port site typically
does not need to be enlarged to allow for
removal. The port is replaced and the retroperitoneal space is inspected under decreased pressure for hemostasis. The ports are removed and
the 10 mm port site fascia is closed with an
absorbable figure of eight stitch. The skin is
closed with subcuticular stitches.
Postoperative Care
The postoperative care of the patient is dictated
by the pathology of the tumor and is covered
elsewhere in this book. The urinary catheter
may be removed 4–6 h postoperatively. The
patient should be ambulating and eating a regular diet the day of the operation.
Outcomes
Fig. 34.2. Right adrenal vein anatomy.
As with the laparoscopic lateral transabdominal approach, complications after this operation are not common. In the largest series to
date, the incidence of incisional hernia, pneumothorax, and wound infection were all less
than 1%. Approximately 8% of patients will
experience hypesthesia or abdominal wall laxity. However, these are almost universally
temporary findings.
456
ENDOCRINE SURGERY
Conclusion
Laparoscopic retroperitoneal adrenalectomy is a
safe, fast, and efficient means of resecting the
adrenal gland in most patients. The major benefits
of this technique over the laparoscopic lateral
transabdominal approach include shorter operative times, avoidance of intraabdominal adhesions,
and potentially fewer complications. Relative contraindications to this technique include tumor size
over 7 cm, body mass index greater than 45, and
preexisting increased intraocular or intraorbital
pressures. This technique should be part of the
armamentarium of endocrine surgeons caring for
patients with adrenal disease.
References
1. Whittle DE, Schroeder D, Purchas SH, et al. Laparoscopic retroperitoneal left adrenalectomy in a patient
with Cushing’s syndrome. Aust NZ J Surg.
1994;64(5):375–6.
2. WalzMK,AlesinaPF,WengerFA,etal.Posteriorretroperitoneoscopic adrenalectomy–results of 560 procedures
in 520 patients. Surgery. 2006;140(6):943–8; discussion
948–50.
3. Gaur DD. Retroperitoneal surgery of the kidney, ureter
and adrenal gland. Endosc Surg Allied Technol.
1995;3(1):3–8.
4. Heintz A, Junginger T. Technique and results of the
retroperitoneoscopic adrenalectomy via a lumbar
approach. Langenbecks Arch Surg. 1998;383(3–4):286–8.
5. Walz MK, Peitgen K, Hoermann R,et al. Posterior retroperitoneoscopy as a new minimally invasive approach
for adrenalectomy: results of 30 adrenalectomies in 27
patients. World J Surg. 1996;20(7):769–74.
6. Morris L, Ituarte P, Zarnegar R, et al. Laparoscopic
adrenalectomy after prior abdominal surgery. World J
Surg. 2008;32(5):897–903.
7. Henry JF, Defechereux T, Raffaelli M, et al. Complications of laparoscopic adrenalectomy: results of 169 consecutive procedures. World J Surg. 2000;24(11):1342–6.
8. Terachi T, Matsuda T, Terai A, et al. Transperitoneal
laparoscopic adrenalectomy: experience in 100 patients.
J Endourol. 1997;11(5):361–5.
9. Zeh HJ, 3rd, Udelsman R. One hundred laparoscopic
adrenalectomies: a single surgeon’s experience. Ann
Surg Oncol. 2003;10(9):1012–7.
10. Guazzoni G, Montorsi F, Bocciardi A, et al. Transperitoneal laparoscopic versus open adrenalectomy for
benign hyperfunctioning adrenal tumors: a comparative
study. J Urol. 1995;153(5):1597–600.
11. Prinz RA. A comparison of laparoscopic and open adrenalectomies. Arch Surg. 1995;130(5):489–92; discussion
492–4.
12. Miyake O, Yoshimura K, Yoshioka T, et al. Laparoscopic
adrenalectomy. Comparison of the transperitoneal and
retroperitoneal approach. Eur Urol. 1998;33(3):303–7.
13. Gagner M, Pomp A, Heniford BT, et al. Laparoscopic
adrenalectomy: lessons learned from 100 consecutive procedures. Ann Surg. 1997;226(3):238–46; discussion 246–7.
14. Walz MK, Alesina PF, Wenger FA, et al. Laparoscopic
and retroperitoneoscopic treatment of pheochromocytomas and retroperitoneal paragangliomas: results of
161 tumors in 126 patients. World J Surg.
2006;30(5):899–908.
15. Walz MK, Gwosdz R, Levin SL, et al. Retroperitoneoscopic Adrenalectomy in Conn’s Syndrome Caused by
Adrenal Adenomas or Nodular Hyperplasia. World J
Surg. 2008;32(5):847–53.
16. Uchida M, Imaide Y, Yoneda K, et al. [Endoscopic adrenalectomy by retroperitoneal approach for primary
aldosteronism]. Hinyokika Kiyo. 1994; 40(1):43–6.
17. Giebler RM, Walz MK, Peitgen K, Scherer RU. Hemodynamic changes after retroperitoneal CO2 insufflation
for posterior retroperitoneoscopic adrenalectomy.
Anesth Analg. 1996;82(4):827–31.
Section IV
Pancreas
“This page left intentionally blank.”
35
Pancreas: Embryology, Anatomy, and Physiology
Tracy-Ann Moo, Rasa Zarnegar and Laurent Brunaud
Embryology of the Pancreas
In the fourth week of embryonic life, the pancreas
begins to develop from endodermal structures
within the primitive duodenum. The pancreas
arises as two separate buds, which subsequently
fuse to form a single organ (Fig. 35.1). The dorsal
pancreatic bud arises from an evagination of the
foregut endoderm and begins to grow into the
dorsal mesentery. The ventral pancreatic bud
develops from the ventral endoderm of the hepatic diverticulum. Development of the ventral bud
occurs by default in endodermal areas where
liver induction by fibroblast growth factor
(FGF) does not take place. Signaling via activin
and FGF originating from the apposing notochord influences the development of the dorsal
bud[1].Bythefifthweek,thegrowthofthe
dorsal bud has surpassed that of the ventral
bud. At this time the duodenum begins to rotate,
bringing the ventral pancreas along with the
common bile duct behind it into contact with
the dorsal bud (Fig. 35.2A). By the sixth week,
both buds have fused so that the dorsal bud
becomes the anterior part of the head, body,
andtailofthepancreas,whiletheventralbud
forms the posterior head and uncinate process
(Fig. 35.2B).
After fusion of the two pancreatic buds, the
two ducts which have developed within each
bud begin to anastomose. Usually, the distal
segment of the ventral pancreatic duct extends
toward the dorsal duct to form this anastomosis.
The duct of the ventral bud then persists as the
main pancreatic duct (duct of Wirsung) while
the dorsal duct regresses. In up to 60% of the
population, the dorsal duct persists as an accessory pancreatic duct (duct of Santorini) [2].
Over the following weeks the main duct elongates into the surrounding mesenchyme giving
rise to secondary ducts, which further elongate
to form terminal ductules. These terminal ducts
are arranged in cell clusters and will form the
future pancreatic acini, which performs the exocrine functions of the pancreas. At about week
12, signaling from surrounding mesenchyme
promotes the differentiation of the acini. As
the acini differentiate they begin to produce
low levels of hydrolic enzyme. By birth, these
acini will have attained a highly differentiated
state, possess an extensive network of protein
synthesizing apparatus, and have the ability to
store inactive digestive enzymes within cytoplasmic zymogen granules.
The islets of Langerhans, the endocrine component of the pancreas, arise from epithelial
cells along the pancreatic acini. These primitive
endocrine cells subsequently proliferate into
distinct cell clusters and migrate into the
mesenchyme of the developing pancreas. In
the tenth week angiogenesis begins within the
mesenchyme; signals from the developing vasculature cause these cells to develop along
an endocrine lineage. Early endocrine cells
J.G.H. Hubbard et al. (eds.), Endocrine Surgery, Springer Specialist Surgery Series,
DOI 10.1007/978-1-84628-881-4_35, Ó Springer-Verlag London Limited 2009
459