[Minimally invasive anterior approaches to the lumbosacral junction].

OBJECTIVE: Minimally invasive anterior preparation of the lumbosacral junction L5/S1 via a retro- or transperitoneal approach, possibility of intervertebral mono- or bisegmental rigid (cage, bone graft) or dynamic (disc arthroplasty) segmental stabilization.

INDICATIONS: Degenerative disc disease (DDD) with or without disc herniation. DDD with translatoric or frontal instability. Degenerative or isthmic spondylolisthesis. Adjacent segment degeneration post fusionem. Failed back surgery syndrome (post discectomy, non-union). Spinal stenosis with dynamic segmental instability. Spondylitis/spondylodiscitis.

CONTRAINDICATIONS: Previous transperitoneal lumbar fusion surgery. Adipositas permagna. Relative: Previous abdominal or gynaecological surgery. Aorta bifurcation and/or venous confluens directly in front of the lumbosacral disc space. Inflammation with large prevertebral granulation tissue formation or psoas abscess. Diseases of the gastrointestinal tract.

SURGICAL TECHNIQUE: Anterior horizontal or vertical midline incision over L5/S1. Retroperitoneal or transperitoneal approach via the left or right lower abdomen. Retroperitoneal technique: medialization of the peritoneal sack towards the contralateral side. Transperitoneal technique: mini laparatomy, dissection of the visceral and parietal peritoneum and mobilization of the bowels laterally. Preparation of the anterolateral circumference of the L5/S1 disc space and mobilization of the vessels laterally. Discectomy and preparation of graft bed.

POSTOPERATIVE MANAGEMENT: Functional postoperative care with mobilisation without external support following total lumbar disc replacement; stable trunk brace for 12 weeks in the case of fusion surgeries; no restrictions for standing, walking or sitting.

RESULTS: Between January 2002 and December 2007, 454 patients (248 female, 206 male, average age 47.3 years, range between 15.4 years and 80.0 years,) underwent anterior surgery in the lumbosacral segment using a minimally invasive anterior approach. The spectrum of indications included monosegmental disc degeneration, spinal stenosis with segmental instability, isthmic oder degenerative spondylolisthesis, spondylodiscitis and others. Dynamic segmental support using total lumbar disc replacement was performed in 251 cases. Rigid stabilization with combined posterior internal fixation and anterior interbody fusion was performed in 203 cases (alternatively cage, tricortical iliac crest bone graft, bone substitutes such as hydroxyapatite or bone morphogenetic protein [BMP]). Approach-related, vascular complications occurred in 0.5 % (mainly left common iliac vein). Injuries of the gastrointestinal tract or urogenital tract (kidney, ureter, bladder) did not occur and there were no infections.