Back pain is one of the most common conditions

Transcription

1 25 Presacral Anterior Lumbar Interbody Fusion (AXIALIF), Mini ALIF 145 Back pain is one of the most common conditions in any population and have a variety of etiologies. 1 The costs for treatment and absence from work are tremendous. 2 Low back pain originates from paraspinal muscles, facet joints, spinal ligaments, failed endplates, or degenerative intervertebral discs. 3 Current strategy for back pain aims to alleviate the symptom and to resolve etiology itself. Surgical options have been considered when conservative treatment fails. 4 Conservative therapies include reduced activity and bed rest, analgesics, muscle relaxants, nonsteroidal antiinflammatory drugs (NSAID) and/or rehabilitation programs. 5 When the conservative therapies fail, Patients undergo a surgical treatment, which inludes decompression, stabilisation and / or fusion. 6 Spinal fusion is the surgical connection of two or more adjacent vertebrae to immobilise. To relieve pain, correct deformity, and improve stability. Indications for spinal fusion include evidence of instability, stenosis that may result in progressive deformity after surgical decompression, i.e. iatrogenic instability, and recurrent disc herniations in some patients caused by segmentary instability. Spinal fusions have been performed for conditions such as infection, trauma, deformity, degenerative conditions, resection for spinal tumours for more than a century. 8 Surgical fusion requires bone graft use to facilitate fusion.bone grafts are either autograft (patient s own bone source), or allograft from a donor The first lumbar anterior interbody fusion was reported in the 1930s. 11 That was open technique. The development of new techniques and technologies and better understanding of surgical anatomy gave rise to minimally invasive spine surgery (MISS) A. Presacral ALIF (anterior lumbar interbody fusion) Presacral ALIF or AXIALIF is performed for the interbody fusion of the lower lumbar vertebrae. Instability due to degenerative disc disease and spondylolisthesis is frequently seen at L4 L5 and L5 S1 levels. which may require fusion to achieve stability and relieve symptoms. Presacral ALIF or transaxial anterior lumbar interbody fusion involves an incision either midline or lateral to the coccyx. The sacrum is separated from the rectum with a mesorectum covered by visceral fascia. This plane serves as the minimally invasive route to the sacrum and the anterior lower lumbar vertebrae. A guide pin introducer is advanced gently along the anterior midline of the sacrum. Tactile feedback and fluoroscopic guidance is essential during the entire AXILIF process to avoid iatrogenic complications of vascualture and intrapelvic organs.. Once a tunnel is achieved to the

2 146 inferior endplate of L5 through the sacrum discectomy is performed using specially designed cuttingloop devices and wire brushes, then bone graft material is packed directly into the disc space. (figure 1-5) Finally, a drill is used to penetrate the upper lumbar vertebrae (the one which will be fused) then a titanium-threaded rod is implanted. The system is often strenghtened with posterior percutaneous pedicle screws Figure 1: Direction of the fixation screw and anatomic relations Figure 2: Opening and dissecting the presacral space to place working cannel. Figure 3: Drilling upto the above vertebrae to be fused to place screw.

3 Presacral Anterior Lumbar Interbody Fusion (AXIALIF), Mini ALIF 147 Figure 4: Cutters and wire brushes for discectomy, and bone grafting. Figure 5: Placing the fixation screw, xray with AXIALIF and posterior percutaneous facet screws Disadvantages of the AXIALIF Most of the spinal surgeons are less familiar with presacral anatomy than general or colorectal surgeons are; therefore,evaluating the presacral anatomy it is critical before performing the procedure in order to reduce the risk of complications. 10 Direct visualization of the discectomy directly is not posssible due to the minimally invasive nature of the procedure. 12 Advantages of the AXIALIF Reduced injury and disruption of the posterior musculature, ligaments, because the disc space is accessed through small incision to access the presacral space. 12 The abdominal cavity is not entered and mobilisation or retraction of the vasculature or intra-abdominal viscera is not necessary AXIALIF process or interbody fusion can be achieved through open or minimally invasive approaches. Open techniques involve dissection, retraction, and mobilization of soft tissues and vital structures such as nerve roots, major vessels, ligaments, annuli, and abdominal viscera. The traditional open approach is often associated with significant postoperative pain, disability, and dysfunction. Minimally invasive techniques are more technically challenging for inexperienced surgeons but they provide symptomatic relief equivalent to that of open approaches based on short-term clinical data. Moreover, clinical benefits of minimally invasive techniques include

4 148 significantly reduced blood loss, postoperative pain, hospital stays, and narcotic usage B. Mini Anterior Lumbar Interbody Fusion (ALIF): This surgical procedure is performed for lumbar spinal fusion. Approach is from the anterior (front) of the patient. L S1 levels can be approached through a limited anterior abdominal incision. A surgical microscope or an open video endoscopy can be helpful in ALIF procedure. Mini ALIF is first described in ,16 and first preliminary results have been released in The advantages of this technique are as follows: Since it is a retroperitoneal spinal procedure this technique is not unknown for spinal surgeons, with the use of retractors only one asistant is enough fort he procedure, the risk for intraabdominal structures is minimal since it is a retroperitoneal approach, ositioning and surgery: Patient is positioned supine and a roll under the back to exaggerate the lumbar has been placed or the table is breaked to increase lordosis which is very important to expose disc space and to capture the implant inserted in the disc space in compression after excess lordosis has been corrected to prevent graft and implant slippage. Generally a lower midline abdominal oblique incision is performed at the level of disc under realtime C-arm scopy. Surgeon generally stands on the right of the patient. Rectus abdominus sheath has been identified and transversely incised after the skin incision. Then laterally under the rectus dissection is carried to enter the retroperitoneal area at the linea arcuata. The anterior lumbar spine is exposed medial to the psoas muscle. Retractors are either fixed to the vertebrae by screws or pins or to the table. (figure 6,7) Mini-ALIF followed by percutaneous PF is an efficacious alternative for low-grade isthmic spondylolisthesis, and posterior decompression is not necessary to relieve leg symptoms. This minimally invasive combined procedure offers many advantages, such as preservation of posterior arch, no nerve retraction, less blood loss, excellent cosmetic results, high fusion rate and early discharge ,20,21 Figure 7: Postoperative x-ray of the mini L5-S1 ALIF Figure 6: Anatomic relations and the entry route for the mini ALIF procedure

5 Indications for Mini- ALIF 1. Degenerative disc disease (DDD) with or without disc herniation that may require a total lumbar disc replacement; 2. For fusion-cases like degenerative instability, tumors, isthmic and 3. Degenerative spondylolisthesis: with a. Instability b. Backpain due to instability 4. Fractures, spondylodiscitis, 5. Failed back syndrome (pseudoarthrosis, post-discectomy) Relative Contraindications 1. Previous abdominal surgeries; 2. Aortic bifurcation and/or venous confluens directly in front of the disc space; 3. Infections with the formation of a large prevertebral granulation tissue or psoas abscess 4. No radiculopathy 5. No resting backpain 6. Absence of complete block on myelography Presacral Anterior Lumbar Interbody Fusion (AXIALIF), Mini ALIF Patients are candidates for mini ALIF. It may be performed either open mini- ALIF or with the help of microscope or endoscopy. 15 As a result, If a patient has pure mechanical backache an anterior fusion and stabilization is a good choice to preserve the disc height, achieve fusion, preserve the Posterior stabilizing soft tissues to prevent iatrogenic instability and adjacent segment degeneration. However there is a high incidance of graft slippage and subsidence risk has been reported in the stand alone grafting and fusion cases. So implants to help the stabilization and to decrease the risk of subsidance and graft slippage have been developed such as cages and anterior instrumentation including plates, screws and rods. Bone grafting and fusion process can be achieved either posteriorly or anteriorly directly between the vertebral bodies. When it is processed anteriorly, first intervertebral disc is removed entirely,then the space is filled with a spinal implant and bone graft to form a cast and a support in between vertebral bodies during fusion period. Eventhough there is a controversy in naming the fusion processes the site of the surgery to the spinal column has a pivot role in the naming. Such as ALIF or AXIALIF. 5-7,

6 150 References 1. Atlas SJ, Deyo RA. Evaluating and managing acute low back pain in the primary care setting. J Gen Intern Med. 2001;16(2): Albert HB, Kjaer P, Jensen TS, Sorensen JS, Bendix T, Manniche C. Modic changes, possible causes and relation to low back pain.med Hypotheses. 2008; 70(2): Manusov EG. Surgical treatment of low back pain. Prim Care. 2012; 39(3): Van Tulder MW, Koes BW, Bouter LM. Conservative treatment of acute and chronic nonspecific low back pain. A systematic review of randomized controlled trials of the most common interventions. Spine (Phila Pa 1976). 1997; 22(18): Zdeblick TA, Hanley EN Jr, Sonntag VK, et al. Indications for lumbar spinal fusion. Introduction Focus Issue Meeting on Fusion. Spine (Phila Pa 1976) 1995; 20(24 Suppl):124S-125S. 6. Chen ZW, Ding ZQ, Zhai WL, et al. Anterior versus posterior approach in the treatment of chronic thoracolumbar fractures. Orthopedics. 2012; 35(2): e He Q, Xu J.Comparison between the antero-posterior and anterior approaches for treating L5-S1 vertebral tuberculosis. Int Orthop 2012; 36(2): Capner N. Spondylolisthesis. Br J Surg 1932; 19: Ito H, Tsuchiya J, Asami G. A new radical operation for Pott s disease. J Bone J Surg 1934; 16B: Ledet EH, Carl AL, Cragg A. Novel lumbosacral axial fixation techniques. Expert Rev Med Devices 2006; 3(3): Shen FH, Samartzis D, Khanna AJ, Anderson DG. Minimally invasive techniques for lumbar interbody fusions. Orthop clin N Am 2007; 38(3): Erkan S, Wu C, Mehbod AA, Hsu B, Pahl DW, Transfeldt EE. Biomechanical evaluation of a new AxiaLIF technique for two-level lumbar fusion. Eur Spine J 2009; 18(6): Marotta N, Cosar M, Pimenta L, Khoo LT. A novel minimally invasive presacral approach and instrumentation technique for anterior L5-Si intervertebral discectomy and fusion. Neurosurg Focus 2006; 20(1): Koc RK, Tucer B. Perkütan Aksiyel Lomber Interbody Füzyon (AxiaLIF) Türk Nöroşirürji Dergisi, 2009, Cilt: 19, Sayı: 3, Mayer HM. A new microsurgical technique for minimally invasive anterior lumbar interbody fusion. Spine 1997; 22: Lin RM, Huang KY, Lai KA. Mini-open anterior spine surgery for anterior lumbar diseases. Eur Spine J 2008; 17: Penta M, Fraser RD. Anterior lumbar interbody fusion a minimum 10-year follow-up. Spine 1997; 22: Pradhan BB, Nassar JA, Delamarter RB et al. Single-level lumbar spinal fusion: a comparison of anterior and posterior approaches. J Spinal Disord Tech 2002; 15: Rajaraman V, Vingan R, Roth P et al. Visceral and vascular complications resulting from anterior lumbar interbody fusion. J Neurosurg 1999; 91: Saraph V, Lerch C, Walochnik N et al. Comparison of conventional versus minimally invasive extraperitoneal approach for anterior lumbar interbody fusion. Eur Spine J 2004; 13: Kim JS, Lee KY, Lee SH, Lee HY. Which lumbar interbody fusion technique is better in terms of level for the treatment of unstable isthmic spondylolisthesis? J Neurosurg Spine. 2010; 12(2): Lee SH, Choi WG, Lim SR, Kang HY, Shin SW. Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis. Spine J Nov-Dec; 4(6): Kaiser MG, Haid RW Jr, Subach BR, Miller JS, Smith CD, Rodts GE Jr. Comparison of the mini-open versus laparoscopic approach for anterior lumbar interbody fusion: a retrospective review. Neurosurgery. 51(1):