Abdominal wall paresis as a complication of minimally invasive lateral transpsoas interbody fusion

Advances and Challenges in Minimally Invasive Spine Surgery

Minimally invasive spine surgery continues to grow and develop. Over the past 50 years, there has been immense growth within this subspecialty of neurosurgery. A deep understanding of the historical context and future directions of this subspecialty is imperative to developing safe adoption and targeted innovation. This review aims to describe the advancements, and challenges that we face today in minimally invasive spine surgery.

New technique of En bloc vertebral resection in the thoracolumbar region assisted by retroperitoneal laparoscopy in a single prone position: first results

PURPOSE

To describe the technique and review the oncological and surgical results of the En Bloc resection assisted by retroperitoneal laparoscopy in a single prone position for tumors in the thoracolumbar region.

METHODS

Monocentric retrospective case study. Procedure was performed in a single prone position by a dual team of spine and thoracovascular surgeons. An endoscopic balloon was inflated in the right retroperitoneal cavity. A plan was developed between the anterior spine and vena cava as well as abdominal aorta with segmental vessels ligation. Structures at risk were safely protected under endoscopy during horizontal or sagittal osteotomies.

RESULTS

From 2021, seven patients aged a median 52 years old (range, 34-67) were included. Involved spinal segments went from T11 to L3. Surgery was aborted in one case due to massive bleeding and ventilating difficulties. There were two partial and four total vertebral resections. Median operating duration and estimated blood loss were 405 min (range, 360-540) and 2.1 L (range, 1.2-19), respectively. Postoperative complications consisted of 1 urinary infection; 1 transient urinary retention; 1 posterior wound infection; 1 pneumothorax; 1 persistent partial motor deficit; 1 transient confusion; 1 pulmonary embolism; 1 CSF leak; 1 subdural hematoma; 1 retroperitoneal lymphocele. All margins were uncontaminated. All patients were alive and ambulatory at last follow-up.

CONCLUSION

Early results suggest En Bloc resection assisted by retroperitoneal videoscopy in tumors from T11 to L3/4 disk space is feasible, less invasive and safe. Careful surgical planning and experience in endoscopic vascular surgery are mandatory.

Challenges Hindering Widespread Adoption of Minimally Invasive Spinal Surgery

Minimally invasive spinal surgery (MISS) techniques offer several beneficial prospects and are being increasingly requested by patients. However, these techniques have not been uniformly adopted by spinal surgeons, and they remain controversial among some. Several barriers have prevented widespread adoption of MISS. These include concerns regarding high start-up costs, limited evidence base, and lack of surgeon training. In addition, the unique approaches involved in MISS expose spinal surgeons to unfamiliar anatomy. Further, while MISS can address a growing spectrum of spinal pathology, some conditions, as well as complications encountered during MISS procedures, require open surgery. This requires surgeons to not only acquire the new and specialized MISS skillset but also maintain their ability to perform open surgery. These factors present challenges common to developing and innovative surgical techniques. Here, we review the barriers preventing wider adoption of MISS and present a framework to promote the safe and effective growth of MISS.

Lateral Lumbar Interbody Fusion: Review of Surgical Technique and Postoperative Multimodality Imaging Findings

The lateral lumbar interbody fusion (LLIF) approach is a minimally invasive surgery that can be used as an alternative to traditional lumbar interbody fusion techniques. LLIF accesses the intervertebral disk through the retroperitoneum and psoas muscle to avoid major vessels and visceral organs. The exposure of retroperitoneal structures during LLIF leads to unique complications compared with other surgical approaches. An understanding of the surgical technique and its associated potential complications is necessary for radiologists who interpret imaging before and after LLIF. Preoperative imaging must carefully assess the location of anatomic structures, including major retroperitoneal vasculature, lumbar nerve roots, lumbosacral plexus, and the genitofemoral nerve, relative to the psoas muscle. Multiple imaging modalities can be used in postoperative assessment including radiographs, CT, CT myelography, and MRI. Of these, CT is the preferred modality, because it can assess a range of complications relating to both the retroperitoneal exposure and the spinal instrumentation, as well as bone integrity and fusion status. This article describes surgical approaches for lumbar interbody fusion, comparing the approaches' indications, contraindications, advantages, and disadvantages; reviews the surgical technique of LLIF and relevant anatomic considerations; and illustrates for interpreting radiologists the normal postoperative findings and potential postsurgical complications of LLIF.

Bilateral thoracic disc herniation with abdominal wall paresis: a case report

We present a rare case of a patient initially presenting with unilateral abdominal wall bulging and radicular pain caused by a lateral disc herniation at Th11/12, later suffering from a hernia recurrence with bilateral disc prolapse and motor deficits. The patient underwent sequesterectomy via a right hemilaminectomy at Th11, and after 8 weeks, a bilateral sequesterectomy with semirigid fusion Th11/12 was performed. Unilateral motor deficits at the thoracic level have been discussed in case reports; a bilateral disc protrusion with abdominal wall bulging occurring as a recurrent disc herniation has never been described before.

Minimally invasive repair for lateral ventral hernia: tailored approach from a hernia centre at a tertiary care institution

INTRODUCTION

Lateral ventral hernia (LVH) is rare and can be primary or secondary. Surgical treatment of this rare hernia type is challenging due the anatomic location and technical challenges in placement and secure anchoring of mesh.

METHOD

Patient demographic data, intra-operative data and post-operative outcomes on all LVH repairs performed with endo-laparoscopic and robotic approach between 2016 to 2018 were reviewed and analysed.

RESULTS

22 LVH were repaired in 21 patients. 9 had primary hernia and 13 had secondary hernia. All patients underwent minimally invasive surgery (MIS) for hernia repair with no conversion to open surgery. Fascial defect closure and placement of mesh were performed in all cases. Different approaches were utilized: 9 hernia repaired with laparoscopic intra-peritoneal on-lay mesh technique with defect closure (IPOM +), 4 had laparoscopic trans-abdominal pre-peritoneal repair (TAPP), another 4 had extended totally extra-peritoneal repair (eTEP), 3 had robotic TAPP (rTAPP) and 2 repaired with trans-abdominal partial extra-peritoneal (TAPE) approach. 4 (19%) of the patients developed post-operative seroma which were managed conservatively. No other significant complication was noted, and no chronic pain or recurrence reported within a minimum follow-up of 12 months.

CONCLUSION

This case series gives a broad outline of possible MIS options available for LVH repair and recommendations for a tailored approach. The surgical technique needs to be individualized according to the size and anatomic location of the defect, other intra-operative findings and patient characteristics.

Lateral Lumbar Interbody Fusion: What Is the Evidence of Indirect Neural Decompression? A Systematic Review of the Literature

BACKGROUND

In the past decade, lateral lumbar interbody fusion (LLIF) has gained in popularity. A proposed advantage is the achievement of indirect neural decompression. However, evidence of the effectiveness of LLIF in neural decompression in lumbar degenerative conditions remains unclear.

QUESTIONS/PURPOSES

We sought to extrapolate clinical and radiological results and consequently the potential benefits and limitations of LLIF in indirect neural decompression in degenerative lumbar diseases.

METHODS

We conducted a systematic review of the literature in English using the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist. Scores on the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain were extracted, as were data on the following radiological measurements: disc height (DH), foraminal height (FH), foraminal area (FA), central canal area (CA).

RESULTS

In the 42 articles included, data on 2445 patients (3779 levels treated) with a mean follow-up of 14.8 ± 5.9 months were analyzed. Mean improvements in VAS back, VAS leg, and ODI scale scores were 4.1 ± 2.5, 3.9 ± 2.2, and 21.9 ± 7.2, respectively. Post-operative DH, FH, FA, and CA measurements increased by 68.6%, 21.9%, 37.7%, and 29.3%, respectively.

CONCLUSION

Clinical results indicate LLIF as an efficient technique in indirect neural decompression. Analysis of radiological data demonstrates the effectiveness of symmetrical foraminal decompression. Data regarding indirect decompression of central canal and lateral recess are inconclusive and contradictory. Bony stenosis appears as an absolute contraindication. The role of facet joint degeneration is unclear. This systematic review provides a reference for surgeons to define the potential and limitations of LLIF in indirect neural elements decompression.

Minimally Invasive Lateral Retropleural and Retroperitoneal Approaches in Patients with Thoracic and Lumbar Osteomyelitis: Description of the Techniques and a Series of 14 Patients

BACKGROUND

The growing interest in minimally invasive approaches to the thoracic and lumbar spine is mostly secondary to the high surgical morbidity and complication rates associated with conventional open approaches. The objective was to report the largest series of patients with thoracic and lumbar vertebral osteomyelitis who underwent multilevel corpectomies using the minimally invasive lateral (MIL) retropleural and retroperitoneal approaches.

METHODS

The surgical techniques of the MIL approaches are illustrated and described in detail. The MIL retropleural approach was performed in 9 patients, MIL retroperitoneal approach in 3 patients, and combined MIL retropleural/retroperitoneal approach in 2 patients with thoracic, lumbar and thoracolumbar vertebral osteomyelitis, respectively.

RESULTS

Multilevel corpectomies were successfully accomplished in all 14 patients using the MIL approaches (11 patients with 2-level corpectomy, 2 patients with 3-level corpectomy, and 1 patient with extension of a 3-level corpectomy to 6 levels). Correction of kyphotic deformity was achieved postoperatively in all 14 patients and remained stable with no proximal junctional kyphosis for a median of 10 months of follow-up on 10 patients; 4 patients were lost to follow-up after discharge from the hospital. Posterior instrumentation was performed in 12 patients to further support the spinal alignment.

CONCLUSIONS

The MIL retropleural and retroperitoneal approaches described in this manuscript are feasible and safe in achieving multilevel corpectomies, anterior column reconstruction, and spinal deformity correction in patients with thoracic, lumbar, and thoracolumbar vertebral osteomyelitis.

The effect of vascular approach surgeons on perioperative complications in lateral transpsoas lumbar interbody fusions

BACKGROUND CONTEXT

Lateral lumbar interbody fusion (LLIF) is a popular technique used in spine surgery. It is minimally invasive, provides indirect decompression, and allows for coronal plane deformity correction. Despite these benefits, the approach to LLIF has been linked to complications associated with the lumbosacral plexus and vascular anatomy. As a result, vascular surgeons may be recruited for the exposure portion of the procedure.

PURPOSE

The purpose of this study was to compare exposure-related complication and postoperative (postop) neuropraxia rates between exposure (EXP) and spine surgeon only (SSO) groups while performing the approach for LLIF.

STUDY DESIGN/SETTING

Retrospective analysis of patients treated at a single institution.

PATIENT SAMPLE

Patients undergoing LLIF procedures between 2012 and 2018.

OUTCOME MEASURES

Operative time, estimated blood loss, fluoroscopy, length of stay (LOS), intra- and postoperative complications, and physiologic measures including pre- and postoperative motor examinations and unresolved neuropraxia.

METHODS

Patients who underwent LLIF were separated into EXP and SSO groups based on the presence or absence of vascular/general surgeon during the approach. The entire clinical history of patients with a decrease in pre- and postop motor examination was reviewed for the presence of neuropraxia. All other intra- and postop exposure-related complications were recorded for comparison. Propensity score matching (PSM) was performed to account for age, Charlson Comorbidity Index (CCI) percentage of LLIFs including L4-L5, and number of levels fused. Independent t test and chi-square analyses were used to identify significant differences between EXP and SSO groups. Statistical significance was set at p<.05.

RESULTS

Two hundred and seventy-five patients underwent LLIF procedures, 155 SSO and 120 EXP. Postoperatively, 26 patients (11.1%) experienced a drop in any Medical Research Council (MRC) score, and two patients (0.7%) experienced unresolved quadriceps palsies. The mean recovery time for MRC scores was 84.4 days. Other complications included 2 pneumothoraces (0.7%), 1 iliac vein injury (0.4%), 14 cases of ileus (5.1%), 3 pulmonary emboli (1.1%), 2 deep vein thrombosis (0.7%), 3 cases of abdominal wall paresis (1.1%), and one abdominal hematoma (0.4%). After PSM, demographics including age, gender, body mass index, CCI, levels fused, and operative time were similar between cohorts. Twenty patients had changes in pre- to postop motor scores (SSO 9.4%, EXP 12.4%, p>.05). Iliopsoas motor scores decreased at the highest rate (EXP 12.4%, SSO 8.2%, p>.05) followed by quadriceps (EXP 5.2%, SSO 4.7%, p>.05). One SSO patient's postop course was complicated by a foot drop but returned to baseline within 1 year. One patient in EXP group developed an unresolved quadriceps palsy (EXP 1.0%, SSO 0.0%, p>.05). Intraoperative exposure complications included one pneumothorax (EXP 1.0%, SSO 0.0%, p>.05). There were no differences in PE/DVT, Ileus, or LOS. In the EXP cohort, three patients experienced abdominal wall paresis (EXP 2.9%, SSO 0.00%, p=.246).

CONCLUSIONS

Comparing the LLIF exposures performed by EXP and SSO, we found no significant difference in the rates of complications. Additional research is needed to determine the etiology of the abdominal wall complications. In conclusion, neuropraxia- and approach-related complications are similarly low between exposure and spine surgeons.

Does the hip positioning matter for oblique lumbar interbody fusion approach? A morphometric study

PURPOSE

To evaluate whether left hip positioning widened the access corridor using oblique lateral interbody fusion (OLIF) approach during right lateral decubitus (RLD).

METHODS

Ten healthy adult volunteers underwent a T2 lumbosacral MRI (1.5 T) in the supine position, RLD position with left hip in extension and then in flexion. L2-L3 to L5-S1 disc spaces were identified. At each level, left psoas surface (in cm²), access corridor (in mm) and vessel movement were calculated in the three positions. Paired t test was used for comparison.

RESULTS

The mean surface of the left psoas ranged from 7.83 to 17.19 cm² in the three positions (p > 0.05). From L2-3 to L4-5, in RLD, when the left hip shifted from extension to flexion, nor the access corridor nor vessel movements were significantly different. When the volunteers shifted from supine to RLD position with hip in extension, arteries moved 3.66-5.61 mm to the right (p < 0.05 at L2-3, L3-4 and L5-S1), while the venous structures moved 0.92-4.96 mm (p < 0.05 at L2-3) to the right. When the position shifted from supine to RLD with hip in flexion, the arterial structures moved 0.47-4.88 mm (p < 0.05 at L2-3 and L3-4) to the right, while the venous structures moved - 0.94 to 4.13 mm (p < 0.05 at L2-3 and L3-4) to the right.

CONCLUSION

Hip positioning was not associated with a significant widening of the surgical corridor. To perform OLIF, we advocate for RLD position with left hip in extension to move away the vascular structures and reduce the psoas volume. These slides can be retrieved under Electronic Supplementary Material.

Incisional Hernia After Minimally Invasive Lateral Retroperitoneal Surgery: Case Series and Review of the Literature

BACKGROUND

Minimally invasive lateral retroperitoneal (lateral-MIS) approaches to the spine involve traversing the lateral abdominal wall musculature and fascia. Incisional hernia is an uncommon approach-related complication.

OBJECTIVE

To review the incidence, treatment, and preventative measures of incisional hernia after lateral-MIS approaches.

METHODS

This is a retrospective review of cases performed by a single surgeon from 2011 to 2016. All patients who underwent lateral-MIS approaches at this institution were included. Patients with a postoperative diagnosis of lateral hernia on physical exam and corroborating advanced imaging findings were included in this study. Cases of flank bulge due to peripheral nerve injury were excluded.

RESULTS

Three-hundred three patients underwent lateral-MIS approaches to the spine. Three (1%) patients with incisional hernia were identified. Two patients presented with a clinically symptomatic incisional hernia, while 1 patient was diagnosed incidentally after a routine abdominal magnetic resonance imaging for an unrelated reason. No patients suffered bowel entrapment or strangulation.

CONCLUSION

Incisional hernia after lateral-MIS approaches is rare. Patients with incisional hernias may be susceptible to bowel incarceration and ischemia, though the incidence of this is probably low. Meticulous closure of the fascia is critical to avoiding this complication.

Complications for minimally invasive lateral interbody arthrodesis: a systematic review and meta-analysis comparing prepsoas and transpsoas approaches

OBJECTIVE

Minimally invasive anterolateral retroperitoneal approaches for lumbar interbody arthrodesis have distinct advantages attractive to spine surgeons. Prepsoas or transpsoas trajectories can be employed with differing complication profiles because of the inherent anatomical differences encountered in each approach. The evidence comparing them remains limited because of poor quality data. Here, the authors sought to systematically review the available literature and perform a meta-analysis comparing the two techniques.

METHODS

A systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A database search was used to identify eligible studies. Prepsoas and transpsoas studies were compiled, and each study was assessed for inclusion criteria. Complication rates were recorded and compared between approach groups. Studies incorporating an analysis of postoperative subsidence and pseudarthrosis rates were also assessed and compared.

RESULTS

For the prepsoas studies, 20 studies for the complications analysis and 8 studies for the pseudarthrosis outcomes analysis were included. For the transpsoas studies, 39 studies for the complications analysis and 19 studies for the pseudarthrosis outcomes analysis were included. For the complications analysis, 1874 patients treated via the prepsoas approach and 4607 treated with the transpsoas approach were included. In the transpsoas group, there was a higher rate of transient sensory symptoms (21.7% vs 8.7%, p = 0.002), transient hip flexor weakness (19.7% vs 5.7%, p < 0.001), and permanent neurological weakness (2.8% vs 1.0%, p = 0.005). A higher rate of sympathetic nerve injury was seen in the prepsoas group (5.4% vs 0.0%, p = 0.03). Of the nonneurological complications, major vascular injury was significantly higher in the prepsoas approach (1.8% vs 0.4%, p = 0.01). There was no difference in urological or peritoneal/bowel injury, postoperative ileus, or hematomas (all p > 0.05). A higher infection rate was noted for the transpsoas group (3.1% vs 1.1%, p = 0.01). With regard to postoperative fusion outcomes, similar rates of subsidence (12.2% prepsoas vs 13.8% transpsoas, p = 0.78) and pseudarthrosis (9.9% vs 7.5%, respectively, p = 0.57) were seen between the groups at the last follow-up.

CONCLUSIONS

Complication rates vary for the prepsoas and transpsoas approaches owing to the variable retroperitoneal anatomy encountered during surgical dissection. While the risks of a lasting motor deficit and transient sensory disturbances are higher for the transpsoas approach, there is a reciprocal reduction in the risks of major vascular injury and sympathetic nerve injury. These results can facilitate informed decision-making and tailored surgical planning regarding the choice of minimally invasive anterolateral access to the spine.

COMPARATIVE STUDY OF LUMBAR PLEXUS PATH ON THE LEFT AND RIGHT SIDES THROUGH THE PSOAS MUSCLE

ABSTRACT Objective: Spine surgery with a minimally invasive lateral approach and validate possible anatomical differences between the right and left sides. Methods: Four measurements (cm) were taken on 38 cadavers: the distance between the lumbar plexus and the transverse process (L4-L5) and the distance between the lumbar plexus and the midline of the lumbar spine, both on the right and left sides. Results: The mean distance between the lumbar plexus and the transverse process of L4-L5 was 1.03 cm and the distance to the midline was 3.99 cm for the right side. The averages of the left side were 1.13 cm and 3.38 cm, respectively. There is statistical difference between the sides (p<0.05) using the non-parametric Wilcoxon test. Conclusions: The authors suggest that the transverse process might be used as an anatomical landmark to define the surgical approach through the psoas muscle. Level of Evidence IV; Cadaveric study.

Delayed Incisional Hernia Following Minimally Invasive Trans-Psoas Lumbar Spine Surgery: Report of a Rare Complication and Management

Background

Lateral lumbar interbody fusion (LLIF) has proved to be a safe tool in the armamentarium of spine surgeons for a variety of lumbar disorders. However, it has some complications related to specific approaches. Incisional hernia following abdominal surgery and anterior spinal surgery is commonly described; however, it is extremely rare following LLIF, with only 1 case reported in short postoperative period. In this report we present the first case of delayed presentation of true incisional hernia following a LLIF procedure and highlight its presentation, mechanism, possible preventive measures, and management.

Methods

We report a 57-year-old lady who underwent L3-4 LLIF. She presented with vague pain in a healed scar area that had no swelling until two years postsurgery, when she developed a painful swelling. On examination, it appeared to be a herniation of abdominal contents.

Results

She underwent a laparoscopic hernia repair surgery. The muscular layers were found to be intact with an attenuated transversalis fascia layer. The repair was reinforced by polypropylene mesh. There was no recurrence at the 6-month follow-up.

Conclusions

Incisional hernia can occur following LLIF months to years following surgery and can have varied presentation. Tight external oblique closure should be performed because the transversalis fascia often cannot be repaired and the quality of a layered closure of the deep obliques is often disappointing. The treating surgeon should be aware of this complication and aggressively surveil for the warning signs, and patients should be counseled about this potential complication.

Recent Advances in Technique and Clinical Outcomes of Minimally Invasive Spine Surgery in Adult Scoliosis

Objective:

Conventional open spinal surgery of adult scoliosis can be performed from anterior, posterior, or combined approach. Minimally invasive spine surgery (MISS) was developed for the purpose of reducing the undesirable effects and complications. This review aimed to make a brief summary of recent studies of the approach and clinical outcomes of MISS in adult scoliosis.

Data Sources:

We conducted a systematic search from PubMed, Medline, EMBASE, and other literature databases to collect reports of surgical methods and clinical outcomes of MISS in treatment of adult scoliosis. Those reports were published up to March 2017 with the following key terms: “minimally invasive,” “spine,” “surgery,” and “scoliosis.”

Study Selection:

The inclusion criteria of the articles were as followings: diagnosed with adult degenerative scoliosis (DS) or adult idiopathic scoliosis; underwent MISS or open surgery; with follow-up data. The articles involving patients with congenital scoliosis or unknown type were excluded and those without any follow-up data were also excluded from the study. The initial search yielded 233 articles. After title and abstract extraction, 29 English articles were selected for full-text review. Of those, 20 studies with 831 patients diagnosed with adult DS or adult idiopathic scoliosis were reviewed. Seventeen were retrospective studies, and three were prospective studies.

Results:

The surgical technique reported in these articles was direct or extreme lateral interbody fusion, axial lumbar interbody fusion, and transforaminal lumbar interbody fusion. Among the clinical outcomes of these studies, the operated levels was 3–7, operative time was 2.3–8.5 h. Both the Cobb angle of coronal major curve and evaluation of Oswestry Disability Index and Visual Analog Scale decreased after surgery. There were 323 complications reported in the 831 (38.9%) patients, including 150 (18.1%) motor or sensory deficits, and 111 (13.4%) implant-related complications.

Conclusions:

MISS can provide good radiological and self-evaluation improvement in treatment of adult scoliosis. More prospective studies will be needed before it is widely used.

A psoas splitting approach developed for outpatient lateral interbody fusion versus a standard transpsoas approach

Background

The technique of transpsoas lateral interbody fusion has been adopted to avoid direct anterior interbody fusion, but lateral fusions have been limited to disc spaces above L5 and are associated with neurologic injuries especially to the lumbar plexus when approaching L4-5. The authors aim to demonstrate a psoas splitting technique to decrease risk of complications associated with the standard transpsoas technique.

Methods

Medical records of 84 patients with prospectively collected data reviewed. Two groups created 44 patients with standard lateral transpsoas approach (group 1) and 40 patients with psoas splitting approach (group 2). The psoas splitting approach utilizes two blades placed anteriorly and posteriorly to split the psoas fibers anteriorly while keeping the posterior blade docked in place where it enters the psoas muscle. The cephalocaudal blades sit above the psoas muscle measuring 30-40 mm shorter than the posterior docking blade.

Results

Thirty-nine males and 45 females, age range 31-71 years, average 58±2 years. Average body mass index (BMI) was 28.4±1.1 kg/m². Mean preoperative standard approach Oswestry disability index (ODI) increased from 48.4±3.0 to 55.2±4.0 compared to psoas splitting approach preoperative ODI means reduced from 45.1±5.0 to 34.9±6.0 (P=0.010). Group 1 mean preoperative visual analogue scale (VAS) score improved from 7.8±0.3 to 3.8±0.6 compared to group 2 mean preoperative VAS score which improved from 7.2±0.4 to 2.7±0.5 (P=0.048). Major complication rate of 20.5% was noted in standard transpsoas approach patients, including inability to walk and dermatome numbness.

Conclusions

The outcomes of this study have shown that patients who had lateral lumbar interbody fusion (LLIF) with the psoas splitting approach had statistically significant improvement in ODI scores compared to the standard approach. Fusion was achieved in all patients and there was no evidence of implant failure or subsidence. In the psoas splitting group the major complication rate was only 5%.

Limitations and complications of minimally invasive spinal surgery in adult deformity

Minimally invasive spine (MIS) surgery has rapidly progressed from simple short segment fusions to large adult deformity corrections, with radiographic and clinical outcomes as good as those of open surgery. Anterior longitudinal ligament release (ALLR) and anterior column realignment (ACR) have been key advancements in the ability to correct deformity using MIS techniques. However, patient selection and appropriate preoperative workup is critical to obtain good outcomes and for complication avoidance. Despite favorable outcomes in spinal deformity surgery, MIS techniques are limited in (I) pronounced cervical or thoracic deformity; (II) patients with prior fusion mass; and (III) severe sagittal imbalance necessitating Schwab 5 osteotomy or higher. Guidelines for proper patient selection are needed to guide MIS spine surgeons in choosing the right candidate.

Minimally invasive anterior, lateral, and oblique lumbar interbody fusion: a literature review

Lumbar interbody fusion involves insertion of a structural graft into an intervertebral disc space to promote bony arthrodesis. It is a well-established surgical strategy for multiple spinal disorders ranging from degenerative conditions to trauma, neoplastic diseases, and deformities requiring correction. Since the inception of lumbar interbody fusion, the most established techniques have been two posterior approaches, the posterior lumbar interbody fusion (PLIF) and the transforaminal lumbar interbody fusion (TLIF). Within the past 15 years, multiple anterolateral approaches to the spine have become widely adopted. These approaches can be performed minimally invasively and spare disruption of the paraspinal muscles and posterior spinal column while enabling wide exposure of the disc space for insertion of interbody grafts much larger than PLIF and TLIF instrumentation. This review highlights three minimally invasive anterolateral approaches: the anterior lumbar interbody fusion (ALIF), the transpsoas lateral lumbar interbody fusion (LLIF), and prepsoas or anterior to the psoas oblique lumbar interbody fusion (OLIF). Relevant topics for discussion and comparison include patient selection, surgical techniques, outcomes, and complications for the three surgical approaches.

Lateral Lumbar Interbody Fusion-Outcomes and Complications

PURPOSE OF REVIEW

Lateral lumbar interbody fusion (LLIF) is a relatively new, minimally invasive technique for interbody fusion. The goal of this review is to provide a general overview of LLIF with a special focus on outcomes and complications.

RECENT FINDINGS

Since the first description of the technique in 2006, the indications for LLIF have expanded and the rate of LLIF procedures performed in the USA has increased. LLIF has several theoretical advantages compared to other approaches including the preservation of the anterior and posterior annular/ligamentous structures, insertion of wide cages resting on the dense apophyseal ring bilaterally, and augmentation of disc height with indirect decompression of neural elements. Favorable long-term outcomes and a reduced risk of visceral/vascular injuries, incidental dural tears, and perioperative infections have been reported. However, approach-related complications such as motor and sensory deficits remain a concern. In well-indicated patients, LLIF can be a safe procedure used for a variety of indications.

Anatomy of psoas muscle innervation: Cadaveric study

Hip flexion weakness is relatively common after lateral transpsoas surgery. Persistent weakness may result from injury to the innervation of the psoas major muscles (PMMs); however, anatomical texts have conflicting descriptions of this innervation, and the branching pattern of the nerves within the psoas major, particularly relative to vertebral anatomy, has not been described. The authors dissected human cadavers to describe the branching pattern of nerves supplying the PMMs. Sixteen embalmed cadavers were dissected, and the fine branching pattern of the innervation to the PMM was studied in 24 specimens. The number of branches and width and length of each branch of nerves to the PMMs were quantified. Nerve branches innervating the PMMs arose from spinal nerve levels L1-L4, with an average of 6.3 ± 1.1 branches per muscle. The L1 nerve branch was the least consistently present, whereas L2 and L3 branches were the most robust, the most numerous, and always present. The nerve branches to the psoas major commonly crossed the intervertebral (IV) disc obliquely prior to ramification within the muscle; 76%, 80%, and 40% of specimens had a branch to the PMM cross the midportion of the L2-3, L3-4, and L4-5 IV discs, respectively. The PMMs are segmentally innervated from the L2-L4 ventral rami branches, where these branches course obliquely across the L2-3, L3-4, and L4-5 IV discs. Knowledge of the mapping of nerve branches to the PMMs may reduce injury and the incidence of persistent weak hip flexion during lateral transpsoas surgery. Clin. Anat. 30:479-486, 2017. © 2017 Wiley Periodicals, Inc.

Anterior to psoas (ATP) fusion of the lumbar spine: evolution of a technique facilitated by changes in equipment

BACKGROUND

Lateral interbody cages have been proven useful in spinal fusions. Spanning both lateral cortical rims while sparing the Anterior Longitudinal Ligament, the lateral interbody cages restore and maintain disc height while adding stability prior to supplemental fixation. The standard approach for their insertion is by a 90-degree lateral transpsoas method. This is relatively bloodless compared to other techniques although has its limitations, requiring neuro-monitoring and being, at times, very difficult at L4/5 due to iliac crest obstruction or an anterior plexus position. An oblique approach, with the patient in lateral decubitus, passes anterior to the iliac crest, retroperitoneal, and being anterior to psoas, eliminates the need for neuro-monitoring.

METHODS

Twenty-one consecutive patients underwent surgery for a total of 32 levels instrumented with the ATP technique. Mean age at the time of surgery was 62.4±7.4 years. There was a 6 months minimum clinical follow up, with imaging to assess fusion, at 6 and 12 months. Indications included symptomatic degenerative lumbar spondylosis +/- spondylolisthesis, leg and back pain. All patients were assessed with the Oswestry Disability Index (ODI), Visual Analog Scale 100 mm for back pain (VASb) and for leg pain (VASl) preoperatively, at 3, 6 and 12 months. Last follow-up was at 12 months for 9 patients and the rest had 6 months follow up.

RESULTS

Statistical analysis showed significance for the results in ODI, VASb and VASl with improvement in all components except for one patient with worsening VASl. Eight patients had complications related to surgery which were still present at last follow-up including moderate weakness of hip flexion and EHL weakness. Lateral cutaneous nerve (LCN) palsy on the side of the approach was also seen as well as sympathectomy effect related to the mobilization of the sympathetic trunk. One patient, who also suffered from multiple sclerosis, experienced psoas abscess 3 months post op that required drainage.

CONCLUSIONS

The left sided anterior to psoas approach offers the most natural corridor to the disc space. The novel instruments and method described here allows insertion of large lateral cages between L2 to L5, without the problems associated with the transpsoas approach, particularly at L4/5.

Acute Renal Infarction After Lateral Lumbar Interbody Spinal Fusion for Kyphoscoliosis

STUDY DESIGN

Case report.

OBJECTIVES

Case report of acute renal infarction following lateral interbody fusion with posterior instrumentation for adult lumbar kyphoscoliosis.

SUMMARY OF BACKGROUND DATA

This is the first reported renal infarction following minimally invasive lateral interbody fusion and posterior spinal instrumentation.

METHODS

We report a case of acute renal infarction in a 72-year-old woman following direct lateral interbody fusion (DLIF) with percutaneous pedicle screw and rod fixation from L1 to L5 for correction of kyphoscoliosis. She reported vague abdominal pain on postoperative day (POD) 7. Abdominal ultrasound findings revealed no abnormalities. The patient tolerated a regular diet, improved in rehabilitative modalities, and had stable vital signs. Abdominal computed tomographic (CT) scan on POD 9 for persistent abdominal pain revealed right renal infarction and right renal artery occlusion. The patient was transferred to the ICU for evaluation, where intravenous heparin was administered and no reperfusion was performed. Transesophageal echocardiography on POD 14 revealed moderate diffuse plaque in the descending aorta.

RESULTS

Surgical correction of kyphoscoliosis through DLIF and posterior spinal instrumentation was performed with improvement of deformity. Subsequent acute renal infarction was noted. The patient was discharged home on POD 21. There were no further adverse events up to the 1-year follow-up.

CONCLUSIONS

A lateral approach to the anterior lumbar spine may precipitate renal artery occlusion and renal infarction in patients with atherosclerosis. Diagnosis of renal infarction requires a high index of suspicion because the primary complaint may be vague back, flank, and abdominal pain. We emphasize the importance of recognizing potential symptoms early to prevent additional renal injury. Caution should be taken with deformities around the origin of the renal arteries and great vessels, especially in patients with atherosclerosis.

LEVEL OF EVIDENCE

Level IV.

Contralateral psoas hematoma after minimally invasive, lateral retroperitoneal transpsoas lumbar interbody fusion: a multicenter review of 3950 lumbar levels

OBJECTIVE Minimally invasive lateral lumbar interbody fusion (LLIF) via the retroperitoneal transpsoas approach is a technically demanding procedure with a multitude of potential complications. A relatively unknown complication is the contralateral psoas hematoma. The authors speculate that injury occurs from segmental vessel injury at the time of contralateral annulus release; however, this is not fully understood. In this multicenter retrospective review, the authors report the incidence of this contralateral complication and its neurological sequelae. METHODS This study was a retrospective chart review of all minimally invasive LLIF performed at participating institutions from 2008 to 2014. Exclusion criteria included an underlying diagnosis of trauma or neoplasia as well as lateral corpectomies or anterior column releases. Single-level, multilevel, and stand-alone constructs were included. All patients underwent preoperative MRI. Follow-up was at least 12 months. All complications and clinical outcomes were self-reported by each surgeon. RESULTS There were 3950 lumbar interbody cages placed via the retroperitoneal transpsoas approach, with 7 cases (0.18% incidence) of symptomatic contralateral psoas hematoma, 3 of which required reoperation for hematoma evacuation. Neurological outcome did not improve after reoperation. Reoperation occurred an average of 1 month after the initial operation due to a delay in diagnosis. In 1 case, segmental artery injury was confirmed at the time of surgery; in the others, segmental vessel injury was suspected, although it could not be confirmed. Neurological deficits persisted in 3 patients while the others remained neurologically intact. Two patients were receiving antiplatelet therapy prior to the procedure. CONCLUSIONS The contralateral psoas hematoma is a rare complication suspected to occur from segmental vessel injury during contralateral annulus release. Detailed review of preoperative imaging for aberrant vessel anatomy may prevent injury and subsequent neurological deficit.

Lateral interbody fusion combined with open posterior surgery for adult spinal deformity

OBJECTIVE Lateral interbody fusion (LIF) with percutaneous screw fixation can treat adult spinal deformity (ASD) in the coronal plane, but sagittal correction is limited. The authors combined LIF with open posterior (OP) surgery using facet osteotomies and a rod-cantilever technique to enhance lumbar lordosis (LL). It is unclear how this hybrid strategy compares to OP surgery alone. The goal of this study was to evaluate the combination of LIF and OP surgery (LIF+OP) for ASD. METHODS All thoracolumbar ASD cases from 2009 to 2014 were reviewed. Patients with < 6 months follow-up, prior fusion, severe sagittal imbalance (sagittal vertical axis > 200 mm or pelvic incidence-LL > 40°), and those undergoing anterior lumbar interbody fusion were excluded. Deformity correction, complications, and outcomes were compared between LIF+OP and OP-only surgery patients. RESULTS LIF+OP (n = 32) and OP-only patients (n = 60) had similar baseline features and posterior fusion levels. On average, 3.8 LIFs were performed. Patients who underwent LIF+OP had less blood loss (1129 vs 1833 ml, p = 0.016) and lower durotomy rates (0% vs 23%, p = 0.002). Patients in the LIF+OP group required less ICU care (0.7 vs 2.8 days, p < 0.001) and inpatient rehabilitation (63% vs 87%, p = 0.015). The incidence of new leg pain, numbness, or weakness was similar between groups (28% vs 22%, p = 0.609). All leg symptoms resolved within 6 months, except in 1 OP-only patient. Follow-up duration was similar (28 vs 25 months, p = 0.462). LIF+OP patients had significantly less pseudarthrosis (6% vs 27%, p = 0.026) and greater improvement in visual analog scale back pain (mean decrease 4.0 vs 1.9, p = 0.046) and Oswestry Disability Index (mean decrease 21 vs 12, p = 0.035) scores. Lumbar coronal correction was greater with LIF+OP surgery (mean [± SD] 22° ± 13° vs 14° ± 13°, p = 0.010). LL restoration was 22° ± 13°, intermediately between OP-only with facet osteotomies (11° ± 7°, p < 0.001) and pedicle subtraction osteotomy (29° ± 10°, p = 0.045). CONCLUSIONS LIF+OP is an effective strategy for ASD of moderate severity. Compared with the authors' OP-only operations, LIF+OP was associated with faster recovery, fewer complications, and greater relief of pain and disability.

Lateral Lumbar Interbody Fusion

The lateral lumbar interbody fusion (LLIF) is a relatively new technique that allows the surgeon to access the intervertebral space from a direct lateral approach either anterior to or through the psoas muscle. This approach provides an alternative to anterior lumbar interbody fusion with instrumentation, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion for anterior column support. LLIF is minimally invasive, safe, better structural support from the apophyseal ring, potential for coronal plane deformity correction, and indirect decompression, which have has made this technique popular. LLIF is currently being utilized for a variety of pathologies including but not limited to adult de novo lumbar scoliosis, central and foraminal stenosis, spondylolisthesis, and adjacent segment degeneration. Although early clinical outcomes have been good, the potential for significant neurological and vascular vertebral endplate complications exists. Nevertheless, LLIF is a promising technique with the potential to more effectively treat complex adult de novo scoliosis and achieve predictable fusion while avoiding the complications of traditional anterior surgery and posterior interbody techniques.

Systematic Review of Thigh Symptoms after Lateral Transpsoas Interbody Fusion for Adult Patients with Degenerative Lumbar Spine Disease

BACKGROUND

Lateral transpsoas interbody fusion (LTIF) is a minimally invasive technique for achieving lumbar spinal fusion. While it has many advantages over open techniques it carries with it a distinct set of risks, most commonly post-operative ipsilateral thigh pain, weakness and sensory disturbances. It is vital for both the surgeon and patient to understand the risks for and outcomes of injury associated with this procedure. We conducted a systematic review of the literature to evaluate the incidence, risks, and long-term clinical outcomes of post-operative thigh symptoms in patients treated with LTIF.

METHODS

We conducted a search of MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and the Cochrane Collaboration Library, using keywords and MeSH terms, for English-language literature published through September 2014, as well as reference lists from key articles. Studies were then manually filtered to retrieve articles that met inclusion criteria. We were interested in studies that reported postoperative lower extremity symptoms after LTIF, such as pain, weakness and changes in sensation. The strength of evidence was determined based on precepts outlined by the Grades of Recommendation Assessment, Development and Evaluation Working Group (GRADE).

RESULTS

A total of 392 articles were initially retrieved, with 24 ultimately meeting criteria for inclusion. The incidence of any post-operative thigh symptom varied, ranging as high as 60.7%, with 9.3% of patients experiencing a motor deficit related to direct nerve injury. Several studies reported cases of persistent symptoms at 6 months follow up. Additionally, inclusion of the L4-5 disc space and a longer duration of surgery were both identified as risks for developing postoperative thigh symptoms.

CONCLUSION

The risk of postoperative thigh symptoms after LTIF is high. Thigh pain, paresthesias and weakness were the most commonly reported symptoms. While most patients' symptoms resolved by 6 months follow up, several studies reported patients with symptoms persistent as far as 12 months removed from surgery. Surgery at the L4-5 disc space and longer surgical duration place the patient at greater risk for developing postoperative and long-term thigh symptoms.

Supra-psoas shallow docking in lateral interbody fusion

BACKGROUND

Lateral interbody fusion techniques have been linked with considerable postoperative morbidity, often the outcome of direct psoas trauma. The most common neurological postoperative complications are transient motor weakness/palsy and sensory dysesthesia, which can be permanent. It appears that these neural complications are a result of passing through the psoas muscle where the potential for nerve injury is significant. The supra-psoas shallow docking method may be a safer alternative and may help minimize morbidities by eliminating or reducing direct psoas injury.

OBJECTIVE

To describe the operative technique of performing lateral interbody fusion using supra-psoas retractor docking.

METHODS

The authors describe the surgical technique including side selection, positioning, and patient outcomes.

RESULTS

Fifteen patients were treated with the supra-psoas shallow docking method. Specifically, no patient reported weakness, numbness, and/or pain on the side that underwent the surgery. In these cases, performing lateral transpsoas interbody fusion using supra-psoas shallow docking appeared to minimize the most common neurological postoperative complications of the surgery, motor weakness/palsy and sensory dysesthesia, which may be a result of dilation of the psoas muscle.

CONCLUSION

The shallow docking technique may decrease postoperative morbidities by docking on top of psoas muscle instead of passing through it. An important potential benefit of this approach is direct visualization of the lumbosacral plexus, which may potentially minimize the postoperative neurological morbidity often encountered in patients after this surgery.

Safety and the anatomy of the retroperitoneal lateral corridor with respect to the minimally invasive lateral lumbar intervertebral fusion approach

Safe and reproducible outcomes of the lateral lumbar intervertebral fusion (LLIF) procedure rely on meticulous care and understanding of the anatomy of the lateral corridor. This review aims to describe the different important anatomic considerations when performing LLIF and offer technical notes that may help increase the safety of this procedure. The LLIF procedure is divided into 5 stages: patient positioning, abdominal wall dissection, retroperitoneal space dissection, deployment of the surgical retractors, and diskectomy. Each stage is preformed in a distinct anatomic compartment that may cause different typical complications.

Robot-assisted triple neurectomy for iatrogenic inguinal pain: a technical note

BACKGROUND

Painful neuromas are a relatively common complication of hernia and abdominal wall surgery.

OBJECTIVE

Surgical neurectomy has the potential to to provide durable relief for chronic pain; however, current surgical approaches are not without morbidity or anatomical challenges.We sought a surgical alternative.

METHODS

In the treatment of a case of incapacitating inguinal pain, we performed an anterior transperitoneal approach using a surgical robot.

RESULTS

This approach was facile and provided elegant anatomical visualization.

CONCLUSION

This case describes the first known robot-assisted laparoscopic triple neurectomy and details a simplified, transperitoneal approach.

Analysis of lumbar plexopathies and nerve injury after lateral retroperitoneal transpsoas approach: diagnostic standardization

Object

The minimally invasive lateral transpsoas approach has become an increasingly popular means of fusion. The most frequent complication is related to lumbar plexus nerve injuries; these can be diagnosed based on distribution of neurological deficit following the motor and/or sensory nerve injury. However, the literature has failed to provide a clinically relevant description of these complications. With accurate clinical diagnosis, spine practitioners can provide more precise prognostic and management recommendations to include observation, nerve blocks, neurodestructive procedures, medications, or surgical repair strategies. The purpose of this study was to standardize the clinical findings of lumbar plexopathies and nerve injuries associated with minimally invasive lateral retroperitoneal transpsoas lumbar fusion.

Methods

A thorough literature search of the MEDLINE database up to June 2012 was performed to identify studies that reported lumbar plexus and nerve injuries after the minimally invasive lateral retroperitoneal transpsoas approach. Included studies were assessed for described neurological deficits postoperatively. Studies that did attempt to describe nerve-related complications clinically were excluded. A clinically relevant assessment of lumbar plexus nerve injury was derived to standardize early diagnosis and outline prognostic implications.

Results

A total of 18 studies were selected with a total of 2310 patients; 304 patients were reported to have possible plexus-related complications. The incidence of documented nerve and/or root injury and abdominal paresis ranged from 0% to 3.4% and 4.2%, respectively. Motor weakness ranged from 0.7% to 33.6%. Sensory complications ranged from 0% to 75%. A lack of consistency in the descriptions of the lumbar plexopathies and/or nerve injuries as well as a lack of diagnostic paradigms was noted across studies reviewed. Sensory dermal zones were established and a standardized approach was proposed.

Conclusions

There is underreporting of postoperative lumbar plexus nerve injury and a lack of standardization of clinical findings of neural complications related to the minimally invasive lateral retroperitoneal transpsoas approach. The authors provide a diagnostic paradigm that allows for an efficient and accurate classification of postoperative lumbar plexopathies and nerve injuries.

Urological injury as a complication of the transpsoas approach for discectomy and interbody fusion

Transpsoas discectomy and interbody fusion has become an increasingly popular method of achieving lumbar interbody fusion, but reports of neurological, vascular, and gastrointestinal complications associated with this procedure have been described in the literature. To date, however, ureteral complications have not been reported with this procedure. The authors report 2 cases of ureteral injury and 1 case of renal injury following this procedure. A low index of suspicion is warranted to work up any patient having flank or abdominal symptoms after undergoing transpsoas discectomy and interbody fusion.

Anterior longitudinal ligament release using the minimally invasive lateral retroperitoneal transpsoas approach: a cadaveric feasibility study and report of 4 clinical cases

Object

Traditional procedures for correction of sagittal imbalance via shortening of the posterior column include the Smith-Petersen osteotomy, pedicle subtraction osteotomy, and vertebral column resection. These procedures require wide exposure of the spinal column posteriorly, and may be associated with significant morbidity. Anterior longitudinal ligament (ALL) release using the minimally invasive lateral retroperitoneal approach with a resultant net lengthening of the anterior column has been performed as an alternative to increase lordosis. The objective of this study was to demonstrate the feasibility and early clinical experience of ALL release through a minimally invasive lateral retroperitoneal transpsoas approach, as well as to describe its surgical anatomy in the lumbar spine.

Methods

Forty-eight lumbar levels were dissected in 12 fresh-frozen cadaveric specimens to study the anatomy of the ALL as well as its surrounding structures, and to determine the feasibility of the technique. The lumbar disc spaces and ALL were accessed via the lateral transpsoas approach and confirmed with fluoroscopy in each specimen. As an adjunct, 4 clinical cases of ALL release through the minimally invasive lateral retroperitoneal transpsoas approach were reviewed. Operative technique, results, complications, and early outcomes were assessed.

Results

In the cadaveric study, sectioning of the ALL proved to be feasible from the minimally invasive lateral retroperitoneal transpsoas approach. The structures at most immediate risk during this procedure were the aorta, inferior vena cava, iliac vessels, and sympathetic plexus. The mean increase in segmental lumbar lordosis per level of ALL release was 10.2°, while global lumbar lordosis improved by 25°. Each level of ALL release took 56 minutes and produced 40 ml of blood loss on average. Visual analog scale and Oswestry Disability Index scores improved by 9 and 35 points, respectively. There were no cases of hardware failure, and as of yet no complications to report.

Conclusions

This initial experience suggests that ALL release through the minimally invasive lateral retroperitoneal transpsoas approach may be feasible, allows for improvement of lumbar lordosis without the need of an open laparotomy/thoracotomy, and minimizes the tissue disruption and morbidity associated with posterior osteotomies.

Motor nerve injuries following the minimally invasive lateral transpsoas approach

OBJECT

The aim of this study was to determine the incidence of motor nerve injuries during the minimally invasive lateral interbody fusion procedure at a single academic medical center.

METHODS

A retrospective chart review of 118 patients who had undergone lateral interbody fusion was performed. Both inpatient and outpatient records were examined to identify any new postoperative motor weakness in the lower extremities and abdominal wall musculature that was attributable to the operative procedure.

RESULTS

In the period from 2007 to 2011 the lateral interbody fusion procedure was attempted on 201 lumbar intervertebral disc levels. No femoral nerve injuries occurred at any disc level other than the L4-5 disc space. Among procedures involving the L4-5 level there were 2 femoral nerve injuries, corresponding to a 4.8% injury risk at this level as compared with a 0% injury risk at other lumbar spine levels. Five patients (4.2%) had postoperative abdominal flank bulge attributable to injury to the abdominal wall motor innervation.

CONCLUSIONS

The overall incidence of femoral nerve injury after the lateral transpsoas approach was 1.7%; however, the level-specific incidence was 4.8% for procedures performed at the L4-5 disc space. Approximately 4% of patients had postoperative abdominal flank bulge. Surgeons will be able to minimize these motor nerve injuries through judicious use of the procedure at the L4-5 level and careful attention to the T-11 and T-12 motor nerves during exposure and closure of the abdominal wall.