Figure l. This 75-year-old man
`had back pain and right anterior
`thigh pain 2 years after he had
`undergone laminectomies lrorn
`L3 to SI with a posterolateral tu-
`sion from L4 to Sl. The lateral ill)
`and anteroposterior (B)
`radio-
`graphs show "vacuum disk” sign
`at L3-L4 with lateral translation
`of the L3 vertebral body on L4.
`His characteristic pain was re-
`produced by an L3—L4 discogram
`perlormed by an independent ra-
`diologist. Lateral (C) and antero-
`posterior (D) radiographs were
`obtained after the procedure us-
`ing the endoscopic retroperito-
`neal approach was performed
`and a transversely oriented BAK
`lusion cage was inserted (I5 mm
`in diameter and 24 mm length).
`The patients back and right leg
`pain resolved after surgery.
`
`
`
`volving the lumbosacral plexus. Ten of the I3 patients in the
`degenerative category had undergone previous destabilizing
`laminectomy procedures elsewhere before referral to the au-
`thors‘ institutions. Flexion- extension lateral radiographs dem-
`onstrated more than 3.5 mm of translation. and anteroposte-
`rior radiographs showed 10 degrees or more of scoliotic disc
`space collapse with ‘vacuum disc sign.“ Positive discograms
`documented a provocative pain response at the unstable level
`(Figure 1). The one patient in the degenerative category who
`had not undergone previous destabilizing surgery had a mas-
`sive L2—L3 central disc herniation with left quadriceps weak-
`ness.
`
`The retroperitoneal approach proved to be very versatile in
`the range of vertebral levels addressed throughout the I8 cases.
`Four patients underwent procedures at Ll-L2. seven patients
`at L3-1.4. and two patients at L4-L5. There were four endo-
`scopic decornpressions and fusions at L2—L3. One patient with
`vertebral osteomyelitis underwent a decompressive procedure
`from L2 to L4.
`
`Surgical Technique. The approach is a combination of video-
`assisted thoracoscopic and laparoscopic methods. The patient
`is put under general endotracheal anesthesia, then turned ln the
`
`= M
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`ms Spine {Volume 23 - Number I3 - I998
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`
`Figure 2. A view ol a transparent optical trochar l0ptiview, Ethi-
`con Endosurgery, Cincinnati. Olll that was used in dissecting the
`retroperitoneal space. Notice the ‘winged keel cutting edges,"
`which only will penetrate a lascial layer, such as the peritoneum,
`it the trochat is forcibly twisted backwards and forwards.
`
`lateral decubitus position on a radiolucent. graphite. Jackson
`.\laximum lateral access table l.O.S.l. Corporation. Union City.
`C.-\) made specifically for the endoscopic approach. with side
`rails designed to accommodate robotic arms‘ and to facilitate
`c-arm fluoroscopy.
`.-\ 1-cm incision is made at the anterior
`portion of the llth rib for approaching from Ll or L2. Below
`Ll. a lateral c-arm fluoroscopic image is obtained. with a metal
`marker overlying the parient‘s skin in the midaxillary line. This
`method optimizes the placement of the working portal directly
`over the unstable disc or vertebral segment. The three tech-
`niques used to dissect the retroperitoneal space are: finger dis-
`section. balloon insufflation. or the use 0 an optical. transpar-
`ent. dissecting trochar. called an Optiview (Ethicon
`Endosurgery..Cincinnati. OH; Figure 1).
`The l0-mm laparoscope is inserted into the Optiview dis-
`secting trochar and refocused once the trochar enters the sub-
`cutaneous tissue. The trochar has two “winged keel” cutting
`surfaces that will not penetrate a fascial layer such as the peri-
`toneum unless the trochar is twisted. Therefore. the three ab-
`dominal muscular layers overlying the peritoneum are pene-
`trated in sequence under direct visualization until the
`preperitoneal fat is encountered. The troehar is used to create a
`potential space that is superficial to the peritoneum until the
`laterally oriented fibers of the psoas major muscle are viewed.
`Usually. the genitofemotal nerve is visualized on the surface of
`the psoas muscle. .-\t this iuncture. a dissection balloon. such as
`that manufactured by Ori in lMenlo Park. CA), can be filled
`with I liter of normal sa ine or air to dissect the retroperitoneal
`layer, more correctly referred to as the retrotransversalis fascia.
`Alternatively. carbon dioxide insufilation can be forced into the
`retroperitoneal cavity up to a pressure of 20 mm of mercury to
`create a working space to triangulate endoscopically.” Once
`the retroperitoneal space is enlarged. at least three portals are
`used—working portal. for pituitary rongeur; curettes; a high-
`powered hurt; or Kerrison rongeurs. A second portal is neces-
`sary for the 10-mm laparoscope. A third portal is used for
`retraction of the psoas major muscle off of the spine in a pos-
`teriordrrectton. The relatively avascular intervertebral discs are
`exposed first. Then, the respective midportions of the adjacent
`vertebral bodies are exposed. and the lumbar segmental vessels
`
`'
`are ligated and divided. Occasionally. .1 fourth l0-mm portal ,5
`used for suctioning in highly vascular cases requiring corpectn.
`mies for tumors or infections. Occasionally. for longer strut
`grafts or-instrumentation. the l0-mm working portal is ex.
`tended in size as much as 5 cm. and an endoscopically assisted,
`mini~laparotomy type of retroperitoneal exposure facilitates
`the cotpectomy or spinal instrumentation. If the size of the
`working portal is extended. of course. the C0; insutflation is
`lost. and the working space in the rettoperitoneum has to be
`maintained by using retractors. This technique is advantageous
`
`‘because the spinal decompression can be accomplished without
`airtight seals. and because standard thoracoscopic instruments
`can be used on the lumbar spine. In other words. throughout
`the remainder of the procedure. spine instruments of heterog-
`enous shaft diameters can be used. and airtight seals around
`trocars are not required.
`Once the vertebral level is confirmed lluoroscopically. the
`transversalis fascia. perinephric fascia. and retroperitoneal
`contents are retracted anteriorly (Figure 3). Electrocautery is
`used to mark the intervertebral discs adjacent to the involved
`lesion. For example. for an L1 cotpectorny. the Ll-L2 and the
`Tll-Ll intervertebral disc spaces are marked. A left-sided ap-
`proach to the surgery is preferred to a right-sided approach.
`because it is easier to dissect the aorta olf the spine than to
`dissect around the more friable inferior vena cava; this is par-
`ticularly true in cases of pyogenic vertebral osteomyelitis or
`cases of neoplasm that occur after radiation therapy with ret-
`roperitoneal fibrosis. The psoas muscle is retracted posteriorly.
`and the ureter is retracted anteriorly.
`lf :1 cotpectomy is being performed" after the two adjacent
`discectomies. the surgeon must have access to three methods of
`hcmostasis:
`I) Endo-Avitene Microfibrillar Collagen l.-\lcon.
`lnc., Humacao. Puerto Rico). 2) Gelfoam (Upjohn Corp..
`Kalamazoo, Ml) soaked in Thrombin (Qgg I :3; Cgrp., Middle-
`town. WI). and 3) bipolar endoscopic electrocautery. At this
`point, the segmental vessels are dissected from the underlying
`bone and elevated with a right-angled clamp. It is important to
`use two vascular clips or an endoloop on the high-pressure side
`of the vessels; the vessels are divided with endoshears.
`.-\s a
`general rule, with any spine procedure the segmental vessels are
`ligated and divided in the anterior half of the vertebral body to
`allow collateral circulation to the neuroforamen and spinal
`cord to occur to its maximum potential. If the lesion is a tumor
`or infection, then a culture and a frozen section are obtained at
`this time in the procedure. A 45-degree. 4-mm—wide endo-
`scopic Kerrison rongeur is used to resect the pedicle. Starting
`cephalad. the instrument is pointed caudad to protect the exit-
`ing spinal roots. Either Kaneda tr-\cromed Corp.. Cleveland.
`OH) heavy-duty tongeurs or a hig . 5-mm burr. such
`as the_;j_r_mner (Wausau. IN) Ultra-power or Anspach with
`long extensions. can be used to hollow out the vertebral body.
`Curettes and small 2-3-mm Kerrison rongeurs are used to com-
`plete the corpectomy. It is important to decompress the spinal
`canal all the way across to the base of the opposite pedicle.
`Decompression is accomplished only when the opposite pedicle
`is palpated or visualized. An autogenous iliac strut graft is
`ramped into place. filling the anterior portion of the corpec-
`tomy defect.
`Alternatively, if the patient only requires a discectomy or
`one-level fusion. an anterior interbody fusion can be accom-
`plished endoscopically. The disc space height is restored by
`using a distraction plug placed from the side. Optimally, two
`
`B:\l
`
`sol’
`adl
`snl
`tee‘
`e.\“
`tn \
`
`

`
`Endoscopic Retroperitoneal lnterbody Fusions - McAfee et al
`
`l-‘I79
`
`Jistraction plugs are ramped into the disc space: one anteriorly
`and one posteriorly. .-\t this point. either a single-ba rrel or dgg-
`ble-barrel drill tube is placed over the distraction plugs. The
`position of the distraction plugs is monitored with anteropos-
`mint and lateral
`lluoroscopy. The center of the distraction
`plugs will correspond with the center of the B.-\K interbody
`fusion cages or endoscopic bone dowels.’ The double-barrel
`tube is tamped into place to engage its teeth into the superior
`and inferior vertebral bodies to maintain the normal height of
`the disc space during the reaming and tapping of holes into the
`intervertebral endplates. The BAK fusion cage or laparoscopic
`bone d'o'wéls. which are composed of -femoral allograft, are
`packed with autogenous iliac graft. The morselized iliac au-
`togralt can be harvested ‘with minimally invasive techniques
`through a 12-mm incision by using a disposable T-shapgd aw],
`.-\fter surgery. the patient is placed in a warm and form
`corset tinterbody fusion) or a thoracolumbar sacral orthosis
`(after a corpectomy), until radiographic fusion is accom-
`plished. lntraoperatively,
`it
`is important to countersink the
`B.-\K fusion cages or laparoscopic bone dowel. The authors
`advocate packing additional bone graft superficial to the cage.
`.-\t 3-6 months after surgery, arthrodesis can be confirmed if
`solid trabecular bone is observed to bridge one vertebrae to the
`adjacent level; this is the most reliable radiographic sign of a
`solid arthrodesis. Three-dimensional. computed-tomography
`reconstruction images of the bone within the cages and flexion-
`extension lateral radiographs also can provide useful informa-
`tion.
`‘
`
`femoral allograft. The long axes of the implants were
`positioned in a transverse direction.
`There were no cases of implant migration or pseudo-
`arthrosis. There were no cases of a radiolucent interface
`between the implant and the vertebral body. There were
`no cases of subsidence more than 1 mm, and there was
`trabecular bony bridging across'the adiacent vertebrae
`laterally by 6 months after surgery.
`One additional patient did not undergo an endoscopic
`stabilization procedure. He was a 47-year-old man with
`an unstable burst fracture who had undergone left ante-
`rior Kaneda instrumentation at the referring institution 3,
`months earlier. He had had an incomplete neurologic
`deficit; a preoperative computed tomography scan had
`demonstrated continued right-sided cauda equina com-
`pression. A right-sided endoscopic decompression was
`performed at the authors‘ institution, and additional sta-
`biliaation was not required.
`.
`For all 18 cases, the mean duration of the surgical
`procedure, including the harvesting of iliac crest bone
`autograft, was 115.2 minutes (range, 60-260 minutes).
`The mean estimated blood loss, which, at the authors‘
`institutions, is determined by the attending anesthesiol-
`ogist, was 205 cc (range, 25-1000 cc). The mean length
`of hospital stay was 2.9 days (range, outpatient proce-
`dure to 5 days).
`
`I Results
`
`
`
`The mean length of the postoperative follow-up period
`was 24.3 months (range. 12-40 months). Fourteen pa-
`tients underwent left-sided retroperitoneal approaches,
`and. in four patients, the pathology was addressed more
`easily on the right side. There were four patients who in
`whom a single incision was made of 5 centimeters or less.
`Fourteen patients had either three or four portals mea-
`suring approximately 12 mm in length. These fourteen
`patients had C0, insufilation to assist the retrotransver-
`salis dissection. The patients with one incision of 5 cen-
`timeters or less had lesions compatible with infection or
`tumor, and the use of C02 insufilation was avoided to
`prevent pressurizing the tumor cells or bacteria systemi-
`cally into the patient’s bloodstream.’-‘°'”"’
`Fusions were performed in 15 of 18 cases by using
`structural bone graft and/or interbody fusion cages. A
`38-year-old radiologist‘s wife with a neurofibroma aris-
`ing from the lumbosacral plexus adjacent to the left com-
`mon iliac vein did not demonstrate preoperative or in-
`traoperative instability; therefore, a fusion procedure
`was not indicated.
`leg patients underwent fusion surgery with custom ‘
`BAK interbody fusion cages. The long axes of the cages
`were in the transverse direction (Figure 4).‘ ln each case,
`the cages were packed with autogenous iliac bone graft
`harvested using a minimally invasive, T-shaped trochar,
`that was 10 mm in diameter. Four patients underwent
`placement of l els fashioned from
`
`
`Complications
`lic -‘
`atients with osto erative C0
`There were three
`(5)33. Case 2 was a 71-year-old man on renal dialysis
`who presented with sepsis. Endoscopic, tettoperitoneal,
`L3—L4 discectomy; debridement; and fusion were per-
`formed to culture and manage an L3—l.4 pyogenic osteo-
`myelitis. Six weeks after surgery, after treatment with
`intervenous antibiotics, the patient underwent postegigr,
`se mental stabilization with Texas Scottish Rite Hos i-
`tal implants from Ll—L$ for more definitive stabilization
`and fusion. The single-level, anterior, inrerbody, endo-
`scopic fusion was not believed to be adequate to prevent
`long-term lumbar ltyphosis and instability.
`
`The second complication occurred intraoperatively in
`Case 3, when a laparoscopic bone dowel partially frac-
`l’
`ured at the point of attachment of the driver into t e
`_central drillin
`in the femoral conical allograft. The
`fractured piece of allograft was extreme y sma (approx-
`imately 0.5 cm X 0.5 cm X 0.5 cm), and the parient’s
`spinal stability was not ieopardized. There were no long-
`patient had a solid arthrodesis,
`S . and the
`which was facilitated by morselized iliac autograft
`placed in the central chamber of all laparoscopic bone
`dowels.
`The third complication occurred in a 69-year-old man
`who u ansverse BAK cage insertion for post-
`Iaminectomy instability at L3-L4. The patient developed
`a h_ematoma in the psoas muscle at L3-L4 after surgery.
`This resulted in a temporary genitofemoral nerve palsy,
`which resolved spontaneously within 3 months.
`
`

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`1480
`
`Spine - Volume 23 - Number 13 - I998
`
`I Discussion
`Rettoperitoneal lumbar fusion and stabilization offers
`several advantages over "conventional anterior transperi-
`roneal laparoscopic approaches of the lumbar spine.”
`- Rctroperitoneal approaches obviate the risk of small
`bowel obstruction or postoperative intraperitoneal ad-
`
`hesions.'°" .—\dditionally, there should be a reduced risk
`of retro rade ejaculation. because the autonomic plexus
`is not dissected. in contrast to preliminary reports of
`transperitoneal laparoscopic approaches.':"'n""’ The pa-
`tient is in the lateral decubitus position. which facilitates
`exposure of the lumbar spine, as gravity helps retract the;
`abdominal contents anreriorly. With the straight. lateral
`position, as opposed to the supine Trendelenburg posi-
`tion required for rransperitoneal laparoscopy, it is easier
`to get orthogonal to the disc space and spine with later-
`ally directed placement of interbody threaded fusion
`cages. The surgeon can use two longer cages in the trans-
`verse axis. with a larger-diameter cage anterior and a
`smaller-diameter cage posterior. thus “customizing” or
`‘
`in" theo timal de ree ofinterverte
`(Figure 5). The same effect of altering the sagirtal plane
`alignment was achieved in the majority of patients in this
`study by using distraction plugs of different diameters to
`adjust the degree of lordosis even before reaming the
`cage diameter. Two longer cages placed laterally via the
`rettoperitoneal approach should he biomechanically
`more stable. because the surface area of the vertebral
`body cage contact area is greater than that achieved
`when using a transperitoneal approach. in addition, the
`anterior longitudinal li ment and osrerior lon itudi-
`nal ligament are not violated with the lateral retroperi-
`toneal approach. With the transperitoneal approach, if
`the surgeon reams, taps. or drills too deeply, the spinal
`canal contents are at risk. With the lateral rettoperito-
`neal approach. however, the orthopedic drilling, ream-
`ing. tapping. and cage insertion are directed toward the
`contralateral psoas muscle instead of the neurologic
`structures.“”
`ln the report of the laparoscopic BAK study" submit-
`ted to the Food and Drug Administration, the incidence
`of iatrogenic inttaoperative disc herniation in patients
`undergoing surgery at one level was 2.8% (6 of 215
`patients) and that in patients undergoing transpetito-
`neal. two-level BAK was 12% (3 of 25 patients). Overall,
`for BAK implants inserted via a straight anterior-to-
`
`posterior direction, the incidence of reoperation for iat-
`rogenic penetration or for pushing inrerverrebral disc
`material into the spinal canal was 2.3%. Furthermore.
`lateral rettoperitoneal procedures obviate the need to
`dissect and mobilize the common iliac vein and artery. as
`is necessary with transperitoneal exposure of the L4 —L5
`intervertebral disc. The authors have found that it is eas-
`ier to make the long axis of two rettoperitoneal cages or
`bone dowels parallel via a shotgun or double-barrel tro-
`char than via a transperitoneal independent trochar.
`.\«-la_ver”‘ reported on 20 patients \vho underwent ret-
`toperitoneal. microsurgical, anterior lumbar interbody
`fusion between January 1. 1995 and January 31. l996.
`In this procedure. an extensive quadrilateral retraction
`frame was used. but anterior stabilization implants were
`not. All patients had undergone an additional posterior
`pedicle screw instrumentation procedure 1-2 weeks ear-
`lier.
`‘
`Boden et all described a video—assisted. lateral. inter-
`transverse-process arthrodesis in a rabbit and a non-
`human primate model. This was a posterior approach.
`which did not involve spinal stabilization.
`Ordwav et all‘-' compared the biomechanical charac-
`teristics of a transversely oriented carbon-fiber cage with
`those of an anteriorly oriented cage in the bovine lumbar
`spine and found that, in most cases. the differences were
`not statistically significant. ln addition. Ordwav et al
`compared two anteriorly oriented cages with just one
`transversely oriented cage, which is a biased comparison.
`However, the carbon fiber cage has been studied exten-
`sively at the current authors’ laboratory as well}; it is
`basically an unreamed spacer that is not screwed into
`. place. The BAK system is inherent
`'
`carbon fiber ca e
`it
`tional distrac-
`tion via distraction plugs which results in better liga-
`mentotaxis. The BA involves a tap that cuts t
`tea 5
`into the two adjacent vertebral end plates. and the BAK
`reduces the strain and micromotion on the bone graft
`contained within the cage more successfully than does
`the rectangular carbon-fiber design."
`There are several potential disadvantages of the min-
`imally invasive. rettoperitoneal approach. Particularly at
`L4-LS, it may be necessary to remove part of the iliac
`crest or place the docking portal through the iliac wing to
`be orthogonal to the L4—L5 disc space.l3‘3° In addition.
`a large mass of psoas muscle containing lumbosacral
`
`
`
`.¢.____..
`
`Figure 3. A. Schematic diagram showing the orientation lot the rettoperitoneal approach. The "X" marks the anterosuperior iliac spine,
`and the three portals are shown by black dots. 3. Initial lateral radiograph of a 76-year-old, dialysis-dependent man with biopsy-conlirmed
`osteomyelitis at L3-L4. lnitially, he was treated at another institution with intravenous antibiotics and a thoracolumbosacral orthosis. When
`he arrived at the authors‘ institution, he was in septic shock. C. A sagittal magnetic resonance image revealing vertebral collapse with
`an associated relropulsed vertebral body fragment and thecal sac compression. 0. A schematic diagram depicting the laparoscopic view
`through the transversalis fascia as the L3-L4 intervertebral disk is exposed. E, A laparoscopic view of the rettoperitoneal space. The black
`arrows demonstrate the interval used to reach the vertebral body. The psoas major (PI is posterior, and the ureter lUl is anterior.
`Perinephric lat (K) is dissected bluntly to expose the interval. F. A schematic diagram showing debridement oi the infected gtanulomatous
`tissue with the anterior thecal sac exposed between the L3 and L4 vertebral bodies posterior to the pituitary rongeur. G. A laparoscopic
`photograph showing a pituitary rongeur debriding the infected L3—L4 intervertebral disc.
`
`
`
`.
`
`

`
`ACan;eta
`
`Enoosnears
`
`nephrenic_
`Fat \.
`
`Genitofemoral
`
`

`
`I.
`
`Figure 4. Anteropostetior and
`lateral radiogtaphs of
`two pa-
`tients obtained after. endoscopic
`retropetitoneal BAK interbody fu-
`sion was perlormed and instru-
`mentation lor postlaminectomy
`instability was placed.AA and B‘
`show a one-cage technique. 0
`and 0 show a two-cage tech-
`nique.
`
`. -. ‘~*~... .:.:u'.-—~.'c-.:~"I3‘ "-
`
`
`
`
`nerve roots may need to be mobilized laterally. However,
`the authors of this study still prefer mobilizing the psoas
`muscle to mobilizing the common iliac vein and artery,
`as is necessary with transperitoneal approaches. The po-
`sition of the ureter constantly needs to be considered in
`rransperitoneal and retropetitoneal minimally invasive
`approaches. One additional advantage of the retropeti-
`toneal approach is that spine surgeons probably will be
`more comfortable performing the approach without de-
`pending on a general surgical “access surgeon."
`Obviously, it is difficult to prove statistically that the
`incidence of complications associated with the retroper~
`itoneal approach is lower than that associated with the
`intraperitoneal endoscopic spinal procedures. because
`even transperitoneal spinal fusion is only a recently de-
`scribed procedure and is still in its infancy. However.
`
`many general surgical. gynecologic. and urologic proce-
`dures in which the retropetitoneal approach is used have
`been reported showing fewer complications than their
`transperitoneal operative counterparts. Leverant et al'-’
`showed that intra-abdominal adhesions do occur with
`laparoscopy. They found intraperitoneal adhesions in 79
`of 124 patients whose only prior surgery was laparos-
`copy; none of the 91 controls without prior laparosco-
`pies in that study had adhesions. Laier et al"’ reported a
`1% incidence of hernias in trocar ports after abdominal
`laparoscopy. Hernias through trocar ports have not been
`described with retropetitoneal approaches.
`The authors of the current study have performed more
`than 150 endoscopic spinal procedures, and have had a
`patient with postoperative small bowel obstruction. This
`obstruction occurred in a patient 2 weeks after he had
`
`

`
`0.:
`
`Endoscopic Retroperitoneal lntcrbody Fusions - .\-lc.-\lee ct .Il
`
`l-883
`
`ptyphosis
`
`Neulral
`
`Lordosis
`
`
`
`Relroperiloneal “Transverse Axis" Cages can be used
`lo "dial in" the desired kyphosis or lordosis.
`
`Figure 5. A schematic diagram illustrating .how dillerential sizing
`ol transversely oriented distraction plugs, interbody bone dowels,
`or lusion cages can “dial
`in" or adjust the desired amount of‘
`lumbar kyphosis or lordosis through a minimally invasive retroper-
`itoneal approach.
`
`undergone anterior transperironeal laparoscopic L4 -L5
`fusion. when the greater olmentum became adherent to
`the posterior peritoneum.
`C‘ Chre 3rn O-. ii;
`Tiusanen et al‘" reported an in
`etro rade
`emgulatign of 5.9% as a complication of anterior inter-
`body fusions and found that it occurred only after trans-
`abdominal procedures. In the report of the first series of
`240 lap-aroscopic BAK interbody fusions and stabiliza-
`tions” submitted to the Food and Drug Administration.
`there were 12 cases (5%) of retrograde ejaculation that
`occurred as a complication of laparoscopic procedures.
`Although the numbers are too small to analyze statisti-
`cally. there probably is a higher incidence of this compli-
`cation at L5—Sl exposure than at L4 -L5 exposure; it has
`been described to occur after anterior fusions to L4 and
`with periaortic lymph node dissection. Retroperitoneal
`exposure. either endoscopic or conventional, is associ-
`ated with a lower incidence of this postoperative compli-
`m[ion_rs..:o
`lt is difficult to compare the morbidity of traditional
`r-ersrrs minimally invasive, endoscopic, anterior, retro-
`peritoneal approaches in the orthopaedic literature di-
`rectl_v. because the length of hospital stay, operative time,
`and length of time out of work have not been reported.
`However. there are three studies of traditional, retroper-
`itoneal, anterior decompressions of the spine in which
`the current authors have participated and reported: those
`of .\-lc.-\fee et all" with 70 patients, .VlcAfee'9 with 185 _
`patients. and .\~lc.-\fee and Zdebliclt" with 23 patients.
`Overall. it is the authors‘ impression that the incidence of
`complications and morbidity is much lower for endo-
`scopic procedures; in particular. associated medical peri-
`operative complications are reduced, includingurinary
`tract infections. post-operative atelectasis, and pneumo-
`nia. However, further experience is clearly necessary to
`confirm this impression. The authors currently are par-
`ticipating in a prospective, multicenter trial by the Na-
`tional Institute of Health to investigate further the com-
`
`plication rates of conventional l‘r.'rSII$ minimally invasive
`techniques.
`In sttmmary. in this report of IS cases of minimally
`invasive. lateral retrnperitoneal. lumbar procedures. the
`main advantages were:
`
`ll the length of stay was less than that associated with
`larger muscle-splitting “open approaches."
`2) the need for mobilization of the great vessels was
`reduced compared with that of transperitoneal lapa-
`roscopic approaches.
`.
`3) the procedure allowed for two larger cages to be
`inserted parallel to one another in a transverse direc-
`tion, horizontal. rather than perpendicular. to the spi-
`nal canal.
`‘
`4) by varying .the diameter of the retroperitoneally
`placed interbody fusion cages. interbody allogr-aft
`bone dowels. or distraction plugs. customization of
`the amount of lumbar lordosis was possible without
`increasing the risk of implant dislodgement or
`pseudo-arthrosis.
`
`Eighteen cases is not a large series. but the results are
`favorable compared with preliminary results of alterna-
`tive techniques.
`
`llelerences
`
`l. Bagby G. Arthrodesis by the distraction—compression
`methods using a stainless steel implant. Orthopaedics l9SS;l I:
`93 l--'3.
`.\lorone .\l.-\. Tocibitaby Y.
`.\loskovitz P.-\.
`2. Boden SD.
`Video-assisted lateral intertransverse process arthrodesis: Val-
`idation ofa non-minimally invasive lumbar spinal fusion tech-
`nique in the rabbit and non-human primate tRltesust models.
`Spine l996;ll:l689—97.
`3. Brantigan jW. .\lc.-\fee PC, Cunningham BW. Wang H.
`Orbegoso C.\'l. lnterbody lumbar fusion using a carbon fiber
`cage implant versus allograft bone: .-\rt investigational study in
`the spanish goat. Spine l994;l9:l-336--l4.
`4. Brodke DS. Dick JC. Kunz DN. .\-lcCabe R. Zdebliclt TA.
`Posterior lumbar interbody fusion: A biomechanical compari-
`son including a new threaded cage. Spine l997_;2l:2b—3l.
`5. Cook T.-\. Dehn TC. Port-site metastases in patients under-
`going laparoscopy for gastrointestinal malignancy. Br J Surg
`l996:83:l4l9-Z0.
`6. C-our DD. Laparoscopic operative retroperitoneoscopy:
`Use of a new device. J Urol l992;l48:l 137-9.
`7. Gels WP. Kim HC, Brennan E].
`.\lcr\fee PC. Wang Y.
`Robotic arm enhancement to accommodate improved elli-
`ciency and decreased resource utilization in complex minimally
`invasive surgical procedures. In: Sieberg H, Weghorst S, Mor-
`gan K, eds. Health Care in the Information Age. Cincinnati.
`OH: IOS Press and Ohmsha. I966:-171-8|.
`B. Goldstein JA. Parker LM. .\rlcr\fee PC. Minimally invasive
`endoscopic surgery of the lumbar spine. Operative Techniques
`in Orthopaedics l997;7:27-35.
`9. Hewett P], Thomas WM. King G. Eaton M. lntraperito-
`neal cell movement during abdominal carbon dioxide insul}la-
`tion and laparoscopy: An In Vivo Model. journal of Diseases ol
`the Colon and Rectum. l996;39(Supp|l:S62—6.
`
`'
`
`

`
`
`
` H8-1 ‘spine - Volume 23 - Number is - 1998
`
`I0. Jacobi CA. Ordemann J, Bohm B. et al. The influence of
`laparotomy and laparoscopy on tumor growth in a rat model.
`Journal of Surgical Endoscopy l997;ll:6l8-21.
`1 1. Jacobi CA. Ordemann J. Bohm B. et al. Does laparoscopy
`increase hacteremia and endotoxemia in a peritonitis model?
`J Surg Endosc l9“:l l:l35-8.
`ll. Jacobs .\l. Verdeia JC. Goldstein HS. Minimally invasive
`colon resection (laparoscopic colectomyl. Surg Laparosc En-
`dosc l99l:l:l-M-50.
`13. Jansen R. FD.-\ Submission. l-ll) B.-\K Laparoscopic Proce-
`dure. Personal Communication.January 17. I997.
`14.
`l\'-.in.iyana .\l. Cunningham BW, Haggerty CJ. Kaneda K.
`.\-lc:\fee PC. .-\n in vitro biomechanical analysis on the stability
`and stress-shielding effect of interbody fusion implants. Pre-
`sented at the annual meeting of the Scoliosis Research Society."
`St. Louis. MD. September 25. I997.
`l5. Ktuitwagen RF, Swinkels BM. Keyser KG. Doesburg WH,
`Schiif CP. Incidence and effect on survival of abdominal wall
`metastases at trocar or puncture sites following laparoscopy or
`paracentesis in women with ovarian cancer. J Gynecol Oncol
`l996;60:233-7.
`I6. Laiet H. Widecrantz S. Heisterberg L. Hernias in trocar
`ports following abdominal laparoscopy: A Review. .-\cta Ob-
`stet Gynecol Scand l997;76:389—93.
`l'.7. Levrant SC. Bieber EJ. Barnes RB. Anterior abdominal
`wall adhesions after laparotomy or laparoscopy. J Am Assoc
`Gynecol Laparosc l997;4:353—6.
`18. Mayer .\vlH. .\lini ALIF: A new microsurgical technique
`for minimally invasive anterior lumbar interbody fusion. Spine
`l997:6:691-700.
`I
`19.
`.\‘lc.-\fee PC. Complications of anterior approaches to the
`thoracolumbar spine: Emphasis on Kanecla instrumentation.
`Clin Orthop l994;306:l 10-9.
`20. Mc.-\fee PC. Bohlman HH. Yuan HA. Anterior decom-
`pression of traumatic thotacolumbar fractures with incomplete
`neurological deficit using a retroperitoneal approach. J Bone
`Joint Surg [Am] l98$;6'/‘:89-I04.
`ll. .\-lc.~\fee PC, Regan JR. Fedder IL. Mack MJ, Geis WP.
`Anterior thoracic corpectomy for spinal cord decompression
`performed endoscopically. Surg Laparosc Endosc l995;5 :339—
`48.
`2.7.. Me.-\fee PC. Regan JR. Zdeblick T, et al. The incidence of
`complications in endoscopic anterior thoracolumbar spinal re-
`constructive surgeryi A prospective mulricenter study compris-
`ing the first I00 consecutive cases. Spine l995;20:l624-32.
`23.
`.\-lc.-\fee PC, Zdeblick TA. Tumors of the thoracic and
`
`lumbar spine: Surgical treatment via the anterior approach_
`J Spinal Disord l989:2:l45—54.
`l-1.
`.\lcDougall EM, Clayman RV. Fadden DT. Retroperirry
`neoscopy: The Washington University Medical School cxperi.
`ence. Urology I994;43:446—56.
`25. Obenchain TG. Cloyd D. Outpatient laparoscopic lumbar
`diskectomy: Description of technique and review of first twen-
`ty-one cases. SurgicalTechnology International l.994;2:-li$—8.
`26. Obenchain TG. Laparoscopic lumbar diskectomy: Case
`report.J Laparoendoscopic Surgery l99l;l:l-35-9.
`27. Ordway NR, Vamvanii V. Zhaoj, Seehan H.-\. Yuan H.-\.
`Mann Kr\. Effect of cage orientation and posterior instrumen-
`tation on the initial stability of the bovine lumbar spine follow-
`ing interbody fusion. Presented at the annual meeting of the
`lnternational Society for Study of the Lumbar Spine. Singa-
`pore. June 6, 1997.
`-
`28. Pier A, Gotz F. Bacher C. Laparoscopic appendectomy in
`625 cases: From innovation to routine. Surg Laparosc Endosc
`l991;l:8—l3.
`29. Reddick EJ. Olsen DE. Laparoscopic laser cholec_vstec-
`tomy: A comparison with mini-lap cholecystectomy. Surg En-
`dosc l989;3:l3l—3.
`30. Regan JJ, Mc:\fee PC, Mack MJ. Atlas of Endoscopic
`Spine Surgery. St. Louis. MO: Quality Medical Publishing.
`lnc., l995.
`'
`31. Scott TR. Graham SM, Flowers JL. Bailey RW. Zucker
`KA. An analysis of l2,397 laparoscopic cholecystectomies. Surg
`Laparosc Endosc 1992;2:l9l—8.
`32. Southern Surgeon‘s Club. A prospective analysis of lSl8
`laparoscopic cholecystectomies. New Engl J Med l99l;32S:
`1073-8.
`33. Talamini MA, Gadacz TR. Equipment and instruction. I