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CHAPTER 21/SURGICAL APPROACHES TO THE LUMBOSACRAL JUNCTION / 233
a preference for a transperitoneal or retroperitoneal
approach to the disc, and any requirement for dissection
to include more proximal discs.
If only the lumbosacral disc requires surgery, then the
transperitoneal approach offers a very direct approach
and straightforward route to this disc. Division of the posterior parietal peritoneum allows direct display of the
bifurcation of the great vessels, and the f ine vessels and
nerves that cross the disc (15). Obvious contraindications
to this approach include acquired conditions resulting in
extensive peritoneal adhesions.
The bifurcation of the aorta and inferior vena cava usually lie at the level of the L5 vertebral body, so the lumbosacral disc is approached between the bifurcations.
Because the vena cava bifurcation is below and to the right
of the aortic bifurcation, the vascular structure most at risk
for injury is the left common iliac vein (16). Considerable
variation exists in the relationship between the bifurcations
and the body of L5 (17). When the bifurcation is proximal
in relation to the spine there are occasions when the lower
two lumbar discs can be approached through the bifurcation. At the other e xtreme, a lo w position of the v essels ma y
result in a need to approach the lumbosacral disc lateral to
the iliac vessels. In this latter situation, the iliolumbar vein
should be divided to assist mobilization of the vessels.
The median sacral artery must be divided. Most surgeons advocate avoiding the use of diathermy about the
presacral plexus over the front of the lumbosacral disc,
for fear of the complication of retrograde ejaculation in
male patients (15). Review has suggested that this complication is rare (18,19), yet it is prudent to cautiously
isolate the presacral plexus and mobilize it to the side
before approaching the lumbosacral disc (Fig. 21-6).
The lumbosacral junction also can be approached by a
retroperitoneal method, with development of the retroperitoneal space, usually on the left side, allowing retraction of the viscera and display of the great vessels and
spine. This is the approach required if the lumbosacral
disc surgery is part of a combined procedure that involves
surgery to the proximal discs.
The transperitoneal approach is best made through a
vertical incision between the recti, with the incision
located between the umbilicus and the symphysis. The
parietal peritoneum is divided longitudinally, and with
the patient in the Trendelenburg position, the abdominal
contents are packed out of the way. This approach presents the posterior wall of the abdomen. Division of the
posterior parietal peritoneum reveals the bifurcation of
the aorta and inferior vena cava, and the lumbosacral disc
between these structures. If the anterolateral disc region
is to be exposed , the v essels must be carefull y retracted to
each side. The surgeon should make the incision low in
the abdomen so that any instrumentation required for
access to the lumbosacral disc can be performed with a
direct view of the inferiorly directed L5-S1 disc space.
Approaches to the lumbosacral disc through a retroperitoneal route generally require a more lateral entry to
the abdominal cavity. Approaches are either muscle-cutting or -splitting (19). Multiple descriptions of approach
options exist, aiming to preserve abdominal wall muscle
function (19–22). Incisions are horizontal or oblique
along the line of the external oblique muscle, and placed
at levels appropriate to allow access to the relevant
discs. The deeper layers are either split or divided lateral
to the recti. Most authors advocate avoidance of extensive longitudinal dissection lateral to the rectus abdominus, because of the risk of denervation of this muscle,
yet this approach may yield a useful extensile approach
that incorporates access to the lumbosacral disc along
with several more proximal discs when extensive procedures are performed (20). In order to prevent possible
denervation of the rectus, we have combined a paramedian longitudinal skin incision with a midline vertical
incision between the recti, and a left-sided retroperitoneal dissection giving access to the lumbosacral junction, and combining this with access to the lumbar discs
as high as L1.
Careful vascular retraction allows display of the lumbosacral disc. The adherent relationship between the
great vessels and the lower lumbar vertebrae mean that
A, B
FIG. 21-6. Diagrammatic representation of the
great vessel bifurcations overlying the lumbosacral disc, and the access to the disc with
vessel retraction.A: Great vessels and presacral
plexus overlying the lumbosacral disc. B: The
lumbosacral disc after retraction of the presacral
plexus and the great vessel bifurcations, and
division of the median sacral artery.
234 /SECTION IV/SURGERY
A B
FIG. 21-7. A: Lateral radiograph of a 20-year-old woman with a delayed diagnosis and presentation
(because of pregnancy) of a posttraumatic lumbosacral dislocation. B: Postoperative lateral radiograph
after anterior transperitoneal approach, extensive mobilization of the great vessels, resection of anterior sacral callus, discectomy, inferior L5 hemicorpectomy (to avoid distraction during ver tebral reduction), and subsequent posterior approach with transforaminal interbody fusion with titanium mesh cages
and posterior pedicle screw instrumentation. The anterior approach was transperitoneal, with extensive
mobilization of the great vessels to allow display of the L5 and S1 vertebral bodies.
greater anterior displays of the L5 body or upper sacrum
require much greater mobilization of the vascular structures. Although this is infrequently required, a vascular
surgeon can provide a very good working area for more
extensive anterior surgery (Fig. 21-7).
REFERENCES
1. Wigh RE. Phylogeny and the herniated disc. South Med J 1979;72:
1138–1143.
2. Wigh RE. The thoracolumbar and lumbosacral transitional junctions.
Spine 1980;5:215–221.
3. Macnab I, Dall D. The blood supply of the lumar spine and its application to the technique of intertransverse lumbar fusion. J Bone Joint
Surg (Britain) 1971;53B:628–637.
4. Last RJ. Anatomy: regional and applied. In:The nervous system. Edinburgh: Churchill Livingstone, 1978:20–31.
5. Mayer TG, Vanharnata H, Gatchel RJ, et al. Comparison of CT scan
muscle measurements and isokinetic trunk strength in postoperative
patients. Spine 1989;14:33–36.
6. See DH, Kraft GH. Electromyography in paraspinal muscles following
surgery for root decompression. Arch Phys Med Rehab 1975;56:80–83.
7. Sihvonen T, Herno A, Paljava L, et al. Local denervation atrophy of
paraspinal muscles in postoperative failed back syndrome. Spine 1993;
18:575–578.
8. Weiner BK, Fraser RD, Peterson M. Spinous process osteotomies to
facilitate lumbar decompressive surgery. Spine 1999;24:62–66.
9. Wiltse LL. The paraspinal sacrospinalis-splitting approach to the lumbar spine. Clin Orthop Rel Res 1973;91:48–57.
10. Fraser RD, Hall DJ. Laminectomy combined with posterolateral stabil-
isation: a muscle-sparing approach to the lumbosacral spine. Eur Spine
J 1993;1:249–253
11. Jonsson B, Stromqvist B, Egund N. Anomalous lumbosacral articulations
and low-back pain. Evaluation and treatment. Spine 1989;14(8):831–834.
12. Santavirta S, Tallroth K, Ylinen P, et al. Surgical treatment of
Bertolotti’s syndrome. Follow-up of 16 patients. Arch Orthop Trauma
Surg 1993;112(2):82–87.
13. Wiltse LL, Spencer CW. New uses and refinements of the paraspinal
approach to the lumbar spine. Spine 1988;13:696–706.
14. O’Brien MF, Peterson D, Crockard HA. A posterolateral microsurgical
approach to extreme-lateral lumbar disc herniation. J Neurosurg 1995;
83:636–640.
15. Freebody D, Bendall R, Taylor RD. Anterior transperitoneal lumbar
fusion. J Bone Joint Surg 1971;53-B:617–627.
16. McAfee PC, Regan JR, Zdeblick T, et al. The incidence of complications in endoscopic anterior thoracolumbar spinal reconstructive
surgery: a prospective multicenter study comprising the first 100 consecutive cases. Spine 1995;20:1624–1632.
17. Capellades J, Pellise F, Rovira A, et al. Magnetic resonance anatomic
study of iliocava junction and left iliac vein positions related to L5-S1
disc. Spine 2000;25:1695–1700.
18. Flynn JC, Price CT. Sexual complications of anterior fusion of the lumbar spine. Spine 1984;9:489–492.
19. Hodgson AR, Wong SK. A description of a technic and evaluation of
results in anterior spina fusion for deranged intervertebral disk and
spondylolisthesis. Clin Orthop 1968;56:133–162.
20. Fraser RD, Gogan WJ. A modified muscle-splitting approach to the
lumbosacral spine. Spine 1992;17(8):943–948.
21. Fraser RD. A wide muscle-splitting approach to the lumbosacral spine.
J Bone Joint Surg Br 1982;64(1):44–46.
22. Allen BT, Bridwell KH. Paramedian retroperitoneal approach to the
anterior lumbar spine. In: Bridwell KH, DeWald RL, eds. The textbook
of spinal surgery. Philadelphia: JB Lippincott, 1991.
CHAPTER 22
Endoscopic Anterior Lumbar Procedures
Ensor E. Transfeldt and John N. Graber
Contemporary surgery of the lumbar spine is evolving
into less invasive methods in an effort to decrease morbidity and hospital stay and speed up recovery and return
to activity and work. The spine is enveloped by a variety
of organs and muscles and traditional exposures alone
have been frequently associated with a greater morbidity
than many of the surgical procedures on the spine itself.
Endoscopic techniques and image-guided surgery provide an exciting opportunity to provide minimal access
to the spine. It is not intended to change the surgery,
although many of the instruments and techniques have
been modified to accommodate the endoscopic access.
The indications for endoscopic access include surgery
for trauma, tumor, infections, deformity, and degenerative conditions.
Laparoscopic- or endoscopic-assisted surgery is an
alternative surgical approach to the spine rather than the
development of a ne w operation. The development of this
technique grew out of an interest in minimally invasive
surgery. Initially, the approach was used for single-level
anterior interbody fusions that evolved for use of interbody cage fixation and now has application for decompression, including corpectomies, débridement, and complex multilevel fusions and fixation. The indications for
endoscopic procedures and the operation itself are the
same as for any open procedure.
The laparoscopic technique requires an anatomic
approach and the same attention to detail of the surgical
technique and biology of fusion and healing as is needed
with open approaches. Laparoscopic techniques are technically more demanding and present a different view of
the anatomy than the conventional open approach. If the
surgeon is unable to perform the operation through a conventional open technique, it is unlikely that he or she will
be able to do it using an endoscope. The procedure
requires a team approach with skill and experience, as
well as a steep learning curve. Benefits include minimally invasive dissection of tissues, preservation of
paraspinal musculature, decreased blood loss, shorter
hospital stay, and faster recovery. This needs to be
weighed against potential disadvantages, including the
need for different instrumentation with unfamiliar tactile
sensations and indirect visualization.
The endoscopic exposure can be done with either gas
insufflation or “gasless” technique. Each has its proponents. Gas insufflation techniques require gas seals and
special trocars as well as special instruments to maintain
intra-abdominal pressure. This changes many aspects of
the surgical procedure. The gasless technique allo ws standard instruments, but has other limitations. Once access
is achieved, specialized equipment may be required to
perform the surgery and insert implants. These instruments frequently are expensive. They have longer shafts
and less tactile feedback and are more difficult to control;
thus, the procedure takes longer. As newer equipment,
including motorized equipment is being developed this
will be improved. Gasless approaches allow the use of
conventional instrumentation. Anatomic considerations
are different, too. Experience helps to determine where to
retract and where pressure can cause injury.
Visualization is made possible by fiberoptics, allowing
illumination and magnification through a camera. Display is usually on a flat two-dimensional screen, thus losing some three-dimensional perception. The technology
does offer the advantage of magnification.
Minimally invasive open techniques, such as the mini
anterior lumbar interbody fusion (ALIF), have been
described and developed and offer an attractive alternative to endoscopic techniques. They have the advantage
of being able to perform the procedure with standard
instruments, more rapid exposure of the spine, and with
comparable morbidity and benefit to laparoscopic access.
Stand-alone anterior fusion and instrumentation, especially with cages has waned in popularity. Laparoscopic
surgical approaches appear to offer less advantage if a
more expensive posterior operation is also required. All
of these factors need to be considered when planning
one’s approach to spine fusion.
235
236 /SECTION IV/SURGERY
CLASSIFICATION OF ENDOSCOPIC ANTERIOR
PROCEDURES
The major categories of laparoscopic surgery are:
I. Transperitoneal
Gas insufflation
Without insufflation
II. Retroperitoneal
Gas insufflation
Without insufflation
Endoscopic-assisted mini open
Anterior lumbar endoscopic surgery developed originally as an extension of the techniques of laparoscopic
surgery for the abdomen by general surgeons. The two
methods of endoscopic access used more widely for anterior lumbar surgery are transperitoneal with insufflation
and retroperitoneal gasless approaches.
TRANSPERITONEAL APPROACH
History
Obenchain (1) described a laparoscopic approach for
anterior L5-S1 fusion without instrumentation. Zuckerman et al. first described instrumented anterior lumbar
fusions through a transperitoneal approach with insufflation in 1995 (2). Matthews et al. (3) and Regan et al. (4)
reported the technique and preliminary results.
Subsequently, the clinical effectiv eness of laparoscopic
ALIF has been reported extensively (3–13).
Regan et al. (14) described 249 patients undergoing
laparoscopic ALIF and compared these to a cohort of 591
consecutive anterior fusions, using the same device. It
basically showed that there was a decreased hospital stay,
decreased blood loss, increased operative time, but operative time improved with time and experience.
Lieberman (15) did a prospective study and found that
the laparoscopic technique resulted in decreased operative time with experience. Mean blood loss was 105 cc
and the operative time was 2 hours, but was reduced to
1.5 hours with experience. The postoperative stay was
4days. Postoperative functional outcomes assessment
clearly needs to be done in these types of studies.
Kleeman and Hiscoe (16) described a prospective
study comparing laparoscopic ALIFs to traditional posterolateral fusions with pedicle screws. He found that the
fusion and complication rates were similar. In the laparoscopic group, blood loss was reduced by 90%, the hospital stay reduced by 50%, and the patients had an earlier
return to work with a faster functional recovery. All the
studies do show that there is a steep learning curve.
The transperitoneal approach with insufflation does
provide direct anterior midline access to the L4-5 and L5S1 levels and occasionally to the C3-4 level. It becomes
increasingly more difficult to employ transperitoneal
endoscopic techniques for more superior levels because
of the sigmoid colon and inferior mesenteric artery. The
major advantage of air insufflation is that it allows fairly
rapid exposure of the lumbar spine, as well as assistance
in “organ retraction” by the increased intra-abdominal
pressure, which helps keep the loops of the bowel out of
the working field. Visual interference by loops of bowel
still occurs and must be dealt with by use of retractors.
The working field is also larger and there is less bleeding
with this technique than that of the gasless transperitoneal
approach. This approach requires trocars with specialized
diaphragms to prevent air leaks. Specialized instruments
and implants are needed to adapt to the use of the trocars.
Instruments for the insertion of interbody cages were
easily adapted to this technique. Trephine discectomies are
use for removal of a cylindric core of disc and a bone fold
cage replaces the space. The disadv antage of this technique
is that it results in a smaller surface area for exposure for
bone fusion. Complete discectomy and preparation of the
end plate is more tedious and difficult through trocars
under conditions of insufflation. This approach has possible benefits for anterior-only surgery (e.g., stand-alone
anterior cages). The addition of a more invasive posterior
approach (e.g., for posterior fixation) eclipses the minimal
invasiveness of the laparoscopic technique.
TECHNIQUE OF TRANSPERITONEAL
APPROACH WITH INSUFFLA TION
Positioning and Pneumoperitoneum
The patient is placed in the supine position with the
arms by the side. The operating table is then placed in
the steep Trendelenburg position. A lumbar roll under
the patient’s pelvis and lumbar spine is also placed in
order to maintain lumbar lordosis, but also to facilitate
use of a C-arm fluoroscope. The standard laparoscopic
equipment used for this procedure includes a 0°, 10 mm
telescope, camera lightsource, and insufflator. However,
the use of angled viewing scopes offers advantage for
more experienced surgeons. A 5 mm, 30° viewing scope
has been our choice. The Trendelenburg position allows
the bowels and the abdominal contents to fall in a
cephalad direction.
A Veress needle is introduced supraumbilically into the
abdomen in order to create a pneumoperitoneum. Pneumoperitoneum is created with carbon dioxide (CO2) gas
insufflation. Alternatively, a supraumbilical or infraumbilical incision is made with the introduction of a Hasson
trocar for use of the endoscope. In this technique, all trocars have special v alv es to seal the escape of gas from the
peritoneum. Through the umbilical trocars, the pneumoperitoneum can also be created. The other portals are then
made under direct vision. The location of the working
portal, which is usually through an 18 mm trocar, is
dependent upon the trajectory of the intervertebral space
being fused, and this assessment is made from preoperative X-rays (Fig. 22-1).
CHAPTER 22/ENDOSCOPIC ANTERIOR LUMBAR PROCEDURES / 237
FIG. 22-1. Typical port placements for transperitoneal
access to the lumbar spine. Camera access through this site
is typical and a working portal is made on the midline lower
abdominal wall in the trajectory of the desired interspace.
The lateral portals are used for dissection and retraction.
FIG. 22-2. The location of the working portal on the abdominal wall is determined by the trajectory of the interspace as
seen on lateral spine films.
for insertion of cages and bone material have also been
designed (Figs. 22-3, 22-4A, B).
Fluoroscopy is used at this point to visualize depth of
the discectomy and reaming, as well as insertion of
implants. The laparoscope allows simultaneous visualization to ensure that vascular and other structures are not
damaged and remain out of the working site.
A 5 mm trocar is then inserted on each side, midway
between the umbilicus and the pubis and lateral to the
epigastric vessels. During the procedure, additional portals can be introduced if needed. The loops of small
bowel are then placed into the epigastrium using special
graspers. The location of the bifurcation of the great
vessels is identified. The working portal is placed at a
site on the abdominal wall in the interspace to be fused
(Fig. 22-2).
Exposure of L5-S1 Disc Space
Having identified the bifurcation of the great vessels,
the posterior peritoneum is incised longitudinally below
the bifurcation and blunt dissection is used to visualize
the L5-S1 disc space and median sacral vessels. The
median sacral artery and vein are then clipped and
divided. The iliac vein and artery must be swept off the
lateral aspect of the interspace with laparoscopic Kittner
dissectors. Ongoing retraction of these vessels can be
done through trocars or by passing Steinmann pins
though the abdominal wall. Dissection should generally
be done without the use of monopolar cautery to avoid
retrograde ejaculation in males. The approach for discectomy will then depend upon the individual preference of
the surgeon. Special instruments for doing discectomies,
as well as special metallic working portals with reamers
Technique for L4-5 Approach
The L4-5 disc space uses a similar approach, but the
exact location of the dissection does depend on preoperative magnetic resonance (MR) images and computed
tomography (CT) scans, which will help determine the
location of the bifurcation. In the unlikely setting where
the bifurcation of the great vessels is located above the
L4-5 interspace, then the same dissection as already
described will be used.
FIG. 22-3. Two sites of trephine partial discectomy are done
on each side of midline on the L5-S1 disc space.
238 /SECTION IV/SURGERY
A
B
FIG. 22-4. A: Postoperative anteroposterior radiograph demonstrating side-by-side cage placement
in the L5-S1 interspace. B: Lateral radiograph
showing the cages in the L5-S1 interspace.
In most cases, the bifurcation is below or at the L4-5.
The iliac artery and vein are f irst identified. Segmental
vessels will also be identified, clipped, and divided and it
is strongly recommended that the ascending iliolumbar
vein be identified, clipped, and divided. These steps are
important in mobilizing the aorta and the vena cava
across the right side of the spine for adequate exposure of
the L4-5 interspace. Percutaneous Steinmann pins can be
placed to the vertebral bodies in order to assist with
retraction or specialized retractors can be used through
one of the working portals. Imaging with the C-arm of
fluoroscope in two planes is necessary to ensure that
implants are inserted centrally in the disc and to the correct depth.
TECHNIQUE OF TRANSPERITONEAL
APPROACH WITHOUT INSUFFLA TION
Maintaining a pneumoperitoneum requires the use of
expensive special gas-sealing ports, as well as special
instruments. The instruments need round shafts in order
to accommodate the diaphragms. Albert Chin introduced
the concept of a mechanical retraction device, the
Laparolift (Origin Medsystems, Menlo Park, CA), which
displaces the anterior abdominal wall and holds it up like
a tent (17).
As a substitute for pneumoperitoneum, this system has
a fan retractor that is inserted into the abdomen in a
closed configuration through a 15 mm minilaparotomy
incision and is then opened up. This fan retractor is
attached to a powered hydraulic table-mounted device
that provides the vertical lift and creates a working space.
The remainder of the portals, including the working portals and lateral portals, are similar to those described in
the transperitoneal approach with insufflation. No gas
seal however, is required. This allows use of conventional
instrumentation and implants.
Before deploying the fan and applying lift, a finger
should be introduced through the infraumbilical incision
into the abdominal cavity and swept around to ensure no
intra-abdominal adhesions are present. The fan retractor is
then inserted and advanced in a plain parallel to the anterior
abdominal wall. The fan blades are then opened and lock ed.
Next, the retractor is attached to a sterile-draped lifting arm,
which has previously been attached to the side rail of the
operating room table. The retractor is then elevated using
the hydraulic system of the lever arm, creating a “tent
effect” by elevating the abdominal wall (Fig. 22-5A, B).
The endoscope is then inserted into the abdominal cavity through the fan insertion incision between the fan
arms. This provides also provides an opportunity to visualize the arms of the fans to ensure that they have not
entrapped any bowel or omentum. A force-limiting device is incorporated into the motor of the lifting arm to
avoid excessive forces. The ancillary portals are then
placed under direct visualization of the endoscope. The
working portal is again strategically placed based on the
trajectory of the interspace to be fused and gauged from
preoperative X-rays. The ancillary ports are simple, rigid
or flexible valveless sleeves, which are used simply to
guide the insertion of instruments. It is possible with the
flexible sleeves to introduce conventional curved and
odd-shaped instruments into the abdominal cavity (Fig.
22-6A, B, C).
CHAPTER 22/ENDOSCOPIC ANTERIOR LUMBAR PROCEDURES / 239
A B
FIG. 22-5. A: Schematic drawing showing Laparolift (Origin Medsystems, Menlo Park, CA) with
hydraulic arm, which is table-mounted and made to apply variable pressure to the anterior abdominal
wall in a lifting fashion so as to create a space f or visualization.B: Clinical photograph showing Laparolift (Origin Medsystems, Menlo Park, CA) in place with laparoscopic cannula placed through same portal as the Laparolift device.This is typically used for passage of the laparoscope.
A
FIG. 22-6. A: The L5-S1 interspace
following complete discectomy. B: A
femoral ring allograft has been prepared and passed through a working
portal and is being placed into the L5S1 interspace.C: The femoral ring allograft has been placed and appropri-
B
ately recessed.
C
240 /SECTION IV/SURGERY
RETROPERITONEAL APPR O A CH
History
The retroperitoneal is a potential space that can be created by dissection in natural anatomic and fascial planes.
Retroperitoneoscopy was first described in the literature
for straightforward smaller urologic and gynecolo gic procedures (18).
Introduction of CO2 insufflators improved visualization
and working space in the retroperitoneum. Fibrous bands
limited the usefulness of CO2 dissection. Balloons were
introduced in the 1990s as an alternative for retroperitoneal
dissection (19–22). The retroperitoneal approach is more
versatile (1,23). McAfee has used a combination of videoassisted thorascopic and laparoscopic methods.
TECHNIQUE FOR RETROPERITONEAL
APPROACH WITHOUT INSUFFLA TION
The spine lies in the retroperitoneal space, which is
only a potential space that can be created by retracting
organs. This potential space is created by manual dissection and by the use of the balloon dissection of tissue
planes. The cavity is then maintained with a mechanical
lifting arm, as well as a specialized retractor. The dissecting balloon has a core cannula for placement of the endoscope so that the balloon dissection is performed under
direct vision. The abdominal peritoneum is dissected off
the abdominal wall and acts as an en velope containing the
abdominal organs out of the view of the spine. A strategically placed working portal allows access for standard
open surgical instruments, thus simplifying the endoscopic access (Fig. 22-7).
The patient is placed in the supine position with a
sandbag under the left flank. Two incisions are made. The
left flank incision for the balloon dissector and endoscope is placed halfway between the 11th rib and the iliac
crest in the anterior auxiliary line. The second incision for
the working portal is strategically placed, depending on
the level and trajectory of the interspace that is to be
fused. This approach allows fusion of any of the interspaces from T12-S1.
The flank incision is approximately 15 mm in length
and dissection is carried out to the lateral abdominal musculature. The external oblique, internal oblique, and
transverses muscles are bluntly separated to expose the
extraperitoneal pararenal fatty tissue. A f inger is again
introduced into this space as a blunt dissector.
The elliptical-shaped preperitoneal dissecting balloon
cannula (PDB) (Medsystems, Inc., Menlo Park, CA) is
then introduced into the retroperitoneal space and once
the balloon is within the incision, the endoscope is introduced into the core of the dissection cannula. The balloon
is then deployed and expanded using an inflation bulb.
Through the inflated balloon it is possible to identify the
line of the peritoneum and observe its dissection on the
FIG. 22-7. Typical port placements for retroperitoneal
access to the anterior lumbar spine. There are two portal
sites. A midline site for access provides the working portal
and a lateral site for a camera, Laparolift (Origin Medsystems, Menlo Park, CA), and retractors.
anterior abdominal wall. This line should be extended as
close to the midline as possible to allow placement of the
anterior working portal (Fig. 22-8A, B).
Once the retroperitoneal space has been developed and
the peritoneum has been reflected from the undersurface
of the anterior abdominal wall, the Laparolift retractor is
inserted and a 10 cm long fan retractor (Laparofan,
Medsystems, Inc., Menlo Park, CA) is inserted through
the left flank incision and the arms of the fan are
deployed under direct endoscopic visualization. The fan
retractor is then attached to the mechanical lifting arm,
which is then elev ated again increasing the ca vity. A flexible nonvalve trocar is then inserted behind the arms of
the fan retractor, through which the endoscope is passed.
A specialized balloon retractor can also be inserted
through the same port or through the working port in the
anterior abdominal wall. This retractor is only inflated
once it has been introduced into the retroperitoneal space
and is helpful in providing retraction of the peritoneum
with its gastrointestinal contents.
The working portal is made through a 12 mm paramedian incision on the anterior abdominal wall, approximately 2 cm lateral to the midline. The level of the incision and the exact location may again depend on the le v el
and trajectory of the interspace to be exposed. Through
the para-midline skin incision, the anterior rectus sheath
is identified and incised. The rectus muscle is retracted
laterally, and the posterior rectus sheath is then incised
and the peritoneum with its contents should have been
CHAPTER 22/ENDOSCOPIC ANTERIOR LUMBAR PROCEDURES / 241
A B
FIG. 22-8. A: Diagram demonstrating the concept of the retroperitoneal endoscopic approach with
exposure of the anterior lumbar spine. A small skin incision is made anterior ly and the rectus muscle
retracted laterally and after exposure of the preperitoneal space, the peritoneum bluntly dissected laterally and posteriorly and retracted to the right side. A Laparolift (Origin Medsystems, Menlo Park, CA)
is placed anterolaterally through a small incision and a laparoscope is inserted through the same portal. The aorta and vena cava are identified and mobilized by clipping and diving the segmental vessels
and then bluntly retracting them to the far side as well.B: Operating room photograph during retroperitoneal gasless exposure.
reflected across the midline, but this can additionally be
assisted through this direct approach. Blunt dissection
with the finger can again be used to sweep the peritoneum further off the abdominal wall if balloon dissection has not provided sufficient exposure.
The peritoneum contains the bowel, which can be
retracted with inflatable or fan retractors. A supplemental
balloon retractor may be introduced through the working
portal as well, if necessary. The remainder of the procedure is then similar to that described in the transperitoneal technique. Exposure of the great vessels is necessary, and again isolation and retraction of these vessels
will depend on the level of the interspace to be exposed.
The L5-S1 interspace is again exposed below the bifurca-
FIG. 22-9. Demonstrating the use of Steinmann pins to hold
vessels and organs retracted. This technique can be
employed in any of the endoscopic procedures discussed in
this chapter. It could also be used for a mini anterior lumbar
interbody fusion.
tion of the great vessels and the L4-5 and more proximal
levels will require a retraction of the aorta and inferior
vena cava to the right of the spine. Percutaneous Steinmann pins may then be used to maintain retraction of the
great vessels (Fig. 22-9). Flexible endoscopic ports are
introduced through the working portal. It is important to
identify all the great vessels as well as the ureter to prevent injury. The sympathetic and parasympathetic presacral plexus are frequently approached from the side and
elevated anteriorly with the great vessels. Lumbar segmental vessels should be clipped for more proximal lumbar spine dissection and at the L4-5 level the recurrent
iliolumbar vein should also be identified and clipped.
Conventional techniques for lumbar discectomy and
preparation of the end plates can then be performed
through this working portal.
Osteotomies and curettes of any shape or size can generally be used as well. In addition, a variety of intervertebral implants can be used, including screw-in cages, tapin cages, cortical allografts, and prosthetic implants.
TECHNIQUE FOR RETROPERITONEAL WITH
INSUFFLATION
There have been a few reports of a retroperitoneal
exposure with insufflation dissection, but these w ere generally not widely embraced. In the anterior abdominal
wall in the midline after exposure of the anterior abdominal wall, the section is carried down through the anterior
and posterior sheath of the rectus muscle after retraction
of the muscle itself. The posterior rectus sheath is then
divided, exposing the extraperitoneal layer at the level of
242 /SECTION IV/SURGERY
A
B
FIG. 22-10. A: Endo-Ring (Medtronic Sofamor Danek,
Memphis, TN) in which Steinmann pins and retractors are
used. The Endo-Ring is stabilized to the table. B: Clinical
use of an Endo-Ring.
the arcuate ligament. Dissection with a finger is used to
free up the peritoneum from the abdominal muscle wall.
An inflatable balloon may be used for dissection and a 10
mm scope introduced bilaterally.
ENDOSCOPIC-ASSISTED MINI-OPEN
APPROACH
Videoscopic-assisted open surgery with an enlarged
working portal is an option. Essentially, this opening
could employ a mini ALIF exposure, which is enhanced
with an endoscope (Fig. 22-10A, B). An endoscope may
be used through a separate portal. The newer technology
of flexible fiberoptics allows the use of a camera and
light source through a thin, flexible scope passed through
the mini ALIF approach itself. The working portal may be
small so that the only person having direct visualization
of the surgical field is the operating surgeon. The addition
of a videoscope allows the assistant to provide assistance
or retraction.
COMPLICATIONS OF ENDOSCOPIC SPINE
SURGERY
Complications can be divided into those caused by the
technique of laparoscopy and those caused by the dissection necessary to expose the spine. Typical laparoscopic
injuries include intestinal or other organ puncture caused
by por t placement, port site bleeding or hernia, cardiovascular dysfunction due to the increased intra-abdominal pressure, and CO2 subcutaneous emphysema (23).
Intraoperative complications include major vessel
injuries, distal arterial embolus, bowel injuries, and bladder and ureter injuries. Postoperative complications
include deep vein thrombosis, ejaculatory dysfunction,
and ileus.
The safest way to decrease complications in endoscopic spine surgery is to use an experienced laparoscopic general surgeon and to do careful preoperative
planning. It is important to maintain good visualization,
orientation, a maximum working space, and appropriate
instrumentation.
It is vitally important to have an “emer gency set” in the
operating room for conversion to open procedures to
minimize blood loss when vessel injuries occur (24).
Conversion should not be considered a failure of the
operation.
Specific complications are primarily related to exposure of the anterior lumbar spine, and usually include
damage to vascular structures and the sympathetic
plexus. Regan et al. (24) compared 249 laparoscopic
patients to 591 open patients undergoing the same operation. Complications were comparable in both groups:
4.2% complications in the open group, 4.9% complications in the laparoscopic group. Device-related complications were increased in the laparoscopic group and these
included disc herniations and no root irritation. Laparoscopic-related complications occurred in 4.7% of patients
in the laparoscopic group and 2.3% in the open group.
The authors point out that the laparoscopic procedures
associated with a learning curve, but once mastered they
believe this is an effective and safe procedure.
In Regan’s series (25), there was a reoperation for
nerve root compression or irritation in four patients, retrograde ejaculation occurred in 4.8% of males, and conversion to open procedure for excessive bleeding
occurred in two patients. Major complications occurred
in 13.4% of the first 40 cases.