Anterior Lumbar Interbody Fusion via Balloon-assisted Endoscopic Retroperitoneal Gasless Approach
Dr. Mark Pleatman and Lawrence Rapp demonstrate anterior exposure of the L4-L5 disk space via a gasless endoscopic approach, followed by insertion of BAK fusion devices.
|
A small incision is first made above the left iliac crest. The abdominal muscles are split and a finger is inserted into the retroperitoneal space. Proper position is verified by being able to palpate the iliacus muscle on the inner surface of the ilium. It is crucial to avoid entering the peritoneal cavity.
|
A balloon dissector (Origin) is inserted into the retroperitoneal space. It is inflated under endoscopic guidance.
|
Here is a view from inside the balloon. One can easily make out details of the retroperitoneal structures.
|
This is another view from the inside of the the balloon. The psoas muscle, part of which contains the very white tendon, is at the lower right. The left ureter is just above the psoas muscle, angling down along the muscle. |
A second incision is made near the midline of the abdomen, taking care to avoid entering the peritoneal cavity. The anterior incision is used for placement of an additional retractor as well as dissecting instruments and the spine instruments. The balloon is then removed, and a retracting device (Laparolift, Origin)is inserted into the incision. It elevates the anterior abdominal wall and allows one to maintain a space in which to work without the need for gas insuflation.
|
An additional retracting device is inserted to help retract the peritoneal sac containing the abdominal organs. After these devices are in place, the peritoneal sac is dissected further and the desired disk space is exposed.
|
It is often necessary to divide a lumbar vein to allow proper retraction of the vena cava. This image demonstrates mobilization of a lumbar vein at the L4-L5 level. The gray device at the right is the balloon retractor which helps retract the peritoneal sac out of the way.
|
Once the disk is identified, a needle is inserted and proper positioning is verified using video fluoroscopy (x-rays). This image shows the needle inserted into the L4-L5 disk space.
|
After the center of the disk space is identified, an alignment guide is inserted to mark the sites where the fusion devices will be placed. This also guides the surgeon as to the proper direction to align the drill bits. The diagrams demonstrate placement of the devices at the L5-S1 level.
|
A small drill hole is made; the drill alignment guide is then withdrawn slightly, and rotated 180 degrees so that the site for the second fusion device can be prepared.
|
The next task is to re-establish the proper disk height. This is done by inserting calibrated "distraction plugs" into the drill holes. Progressively larger plugs may be inserted until a tight fit is achieved.
|
With a distraction plug in one drill hole, a reaming device is inserted into the other drill hole.
|
This is a picture of the Drill Tube Guide being placed, in preparation for placement of the Drill Tube Sheath.
|
The Drill Tube Sheath is now in place. It anchors the assembly in place. The hole for the BAK device is reamed and threads are tapped. The device is then inserted.
|
The Drill Tube assembly has been removed, and one can see the BAK device in place.
|
The Drill Tube Guide is now inserted on the opposite side and the procedure is repeated for the second implant. One can see how difficult the exposure is at this level because of the need to retract the aorta and inferior vena cava to the patient's right side.
|
Bone fragments taken from the patient's hip are now being packed into the BAK device to encourage growth of bone into the graft.
|
|
