Minimally-Invasive Assisted Robotic Spine Surgery (MARSS).

Minimally-Invasive robotic spine surgery (MARSS) has expanded the surgeons armamentarium to treat a variety of spinal disorders. In the last decade, robotic developments in spine surgery have improved the safety, accuracy and efficacy of instrumentation placement. Additionally, robotic instruments have been applied to remove tumors in difficult locations while maintaining minimally invasive access. Gross movements by the surgeon are translated into fine, precise movements by the robot. This is exemplified in this chapter with the use of the da Vinci robot to remove apical thoracic tumors. In this chapter, we will review the development, technological advancements, and cases that have been conducted using MARSS to treat spine pathology in a minimally invasive fashion.

Use of Local Morselized Bone Autograft in Minimally Invasive Transforaminal Lumbar Interbody Fusion: Cost Analysis.

OBJECTIVE: Few studies have investigated the financial influence of surgical site local morselized bone autograft (LMBA) on the overall cost of spinal arthrodesis procedures. The purpose of this study is to evaluate the potential savings from introducing LMBA in spinal fusion procedures compared with no LMBA use. METHODS: Retrospectively, cost analysis was conducted on a single-center data collected from 266 patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) ranging from L1 through S1 during a period of approximately 4 years. Cost data were obtained from individual patient invoices from the distributor. Sensitivity analyses were also conducted for different costs of allograft and LMBA. RESULTS: A total of 282 levels were grafted in 266 subjects. The total quantity of LMBA harvested was 2433.5 mL, and a total of 1610 mL of allograft (Trinity Elite, ORTHOFIX, Lewisville, Texas, USA) were used. The overall cost savings from introducing LMBA in MI-TLIF surgery were $1,094,931 over the 4-year period with mean direct cost saving of $4116.28 per patient based on reduction in allograft. Results for cost savings per patient were sensitive to different direct costs of allograft and LMBA. A >95% fusion rate was achieved based on dynamic radiographs evaluated by an independent radiologist. CONCLUSIONS: LMBA is a cost-saving bone graft extender option in MI-TLIF procedures while achieving high fusion rates. The savings are mainly achieved by reducing the amount of allograft needed and subsequent reduction in the total bone graft costs. Further research needs to be performed regarding long-term economic benefit.

The technological development of minimally invasive spine surgery.

Minimally invasive spine surgery has its roots in the mid-twentieth century with a few surgeons and a few techniques, but it has now developed into a large field of progressive spinal surgery. A wide range of techniques are now called "minimally invasive," and case reports are submitted constantly with new "minimally invasive" approaches to spinal pathology. As minimally invasive spine surgery has become more mainstream over the past ten years, in this paper we discuss its history and development.

Quality-of-life outcomes with minimally invasive transforaminal lumbar interbody fusion based on long-term analysis of 304 consecutive patients.

STUDY DESIGN: This was a prospective clinical study that took place in an outpatient spine clinic. OBJECTIVE: To demonstrate the short-/long-term outcomes from a large cohort of patients undergoing minimally invasive transforaminal lumbar interbody fusion (MITLIF). SUMMARY OF BACKGROUND DATA: Long-term prospective outcomes in patients undergoing minimally invasive spinal fusion for debilitating back pain has not been well studied. METHODS: Presenting diagnosis was determined from clinical findings and radiographical (radiograph, magnetic resonance image, computed tomographic scan) evaluations preoperatively. Patients were assessed with outcome measures preoperatively, and postoperatively at 2 weeks, 3 months, 6 months, 12 months, 24 months, and annually 2 to 7 years (mean follow-up: 47 mo) final follow-up. The rate of postoperative complications and reoperations at the initial level of MITLIF and adjacent level(s) were followed. Fusion rates were assessed blinded and independently by radiograph. RESULTS: Visual analogue scale scores decreased significantly from 7.0 preoperatively to 3.5 at mean 47-month follow-up. Oswestry Disability Index scores declined from 43.1 preoperatively to 28.2 at mean 47-month follow-up. Short-Form 36 mental component scores increased from 43.8 preoperatively to 49.7 at 47-month follow-up. Short-Form 36 physical component scores increased from 30.6 preoperatively to 39.6 at 47-month follow-up (P < 0.05). CONCLUSION: This prospectively collected outcomes study shows long-term statistically significant clinical outcomes improvement after MITLIF in patients with clinically symptomatic spondylolisthesis and degenerative disc disease with or without stenosis. MITLIF resulted in a high rate of spinal fusion and very low rate of interbody fusion failure and/or adjacent segment disease requiring reoperation while reducing postoperative complications. LEVEL OF EVIDENCE: 3.

Use of the da Vinci minimally invasive robotic system for resection of a complicated paraspinal schwannoma with thoracic extension: case report.

BACKGROUND AND IMPORTANCE: Applications of robotics to minimally invasive spine surgery have produced several benefits while sparing patients the morbidity of traditional open surgery. Minimally invasive spine surgery offers the advantages of less pain and less blood loss, along with quicker recovery and shorter hospital stays. The da Vinci robotic surgical system has recently been adapted to neurosurgical applications. This article details a posterior approach using a tubular retraction system in conjunction with an anterior approach using the da Vinci robot to completely remove large spinal schwannomas with intrathoracic extension. This technique is an example of a novel application of existing technology initially developed for other applications. CLINICAL PRESENTATION: Two patients with large thoracic schwannomas extending into the chest cavity are reviewed. We present images and video of the combined minimally invasive approach used to completely remove the lesions without complications. CONCLUSION: This report describes a novel neurosurgical application of an existing minimally invasive robotic surgical system.

Complication management with minimally invasive spine procedures.

Spine surgery as we know it has changed dramatically over the past 2 decades. More patients are undergoing minimally invasive procedures. Surgeons are becoming more comfortable with these procedures, and changes in technology have led to several new approaches and products to make surgery safer for patients and improve patient outcomes. As more patients undergo minimally invasive spine surgery, more long-term outcome and complications data have been collected. The authors describe the common complications associated with these minimally invasive surgical procedures and delineate management options for the spine surgeon.

In vivo intervertebral disc regeneration using stem cell-derived chondroprogenitors.

OBJECT: There is currently no biologic therapy to repair or restore a degenerated intervertebral disc. A potential solution may rest with embryonic stem cells (ESCs), which have a potential to grow indefinitely and differentiate into a variety of cell types in vitro. Prior studies have shown that ESCs can be encouraged to differentiate toward specific cell lineages by culture in selective media and specific growth environment. Among these lineages, there are cells capable of potentially producing nucleus pulposus (NP) in vivo. In this investigation, the authors studied ESCderived chondroprogenitors implanted into a degenerated disc in a rabbit. For this purpose, a rabbit model of disc degeneration was developed. METHODS: A percutaneous animal model of disc degeneration was developed by needle puncture of healthy intact discs in 16 New Zealand white rabbits. Series of spine MR imaging studies were obtained before disc puncture and after 2, 6, and 8 weeks. Prior to implantation, murine ESCs were cultured with cis-retinoic acid, transforming growth factor beta, ascorbic acid, and insulin-like growth factor to induce differentiation toward a chondrocyte lineage. After confirmation by MR imaging, degenerated disc levels were injected with chondrogenic derivatives of ESCs expressing green fluorescent protein. At 8 weeks post-ESC implantation, the animals were killed and the intervertebral discs were harvested and analyzed using H & E staining, confocal fluorescent microscopy, and immunohistochemical analysis. Three intervertebral disc groups were analyzed in 16 rabbits, as follows: 1) Group A, control: naïve, nonpunctured discs (32 discs, levels L4-5 and L5-6); 2) Group B, experimental control: punctured disc (16 discs, level L2-3); and 3) Group C, experimental: punctured disc followed by implantation of chondroprogenitor cells (16 discs, level L3-4). RESULTS: The MR imaging studies confirmed intervertebral disc degeneration at needle-punctured segments starting at approximately 2 weeks. Postmortem H & E histological analysis of Group A discs showed mature chondrocytes and no notochordal cells. Group B discs displayed an intact anulus fibrosus and generalized disorganization within fibrous tissue of NP. Group C discs showed islands of notochordal cell growth. Immunofluorescent staining for notochordal cells was negative for Groups A and B but revealed viable notochordal-type cells within experimental Group C discs, which had been implanted with ESC derivatives. Notably, no inflammatory response was noted in Group C discs. CONCLUSIONS: This study illustrates a reproducible percutaneous model for studying disc degeneration. New notochordal cell populations were seen in degenerated discs injected with ESCs. The lack of immune response to a xenograft of mouse cells in an immunocompetent rabbit model may suggest an as yet unrecognized immunoprivileged site within the intervertebral disc space.

Minimally invasive spine surgery: a historical perspective.

Minimally invasive spine surgery has gained considerable momentum and increased acceptance among spine surgeons throughout the years. An understanding and awareness of the development of minimally invasive spine surgery and its role in the operative treatment of various spine conditions is imperative. This article provides a succinct historical perspective of the development of spine surgery from the more traditional, open procedures to the use of more "minimal access" or minimally invasive spine surgery procedures.

Techniques for the operative management of thoracic disc herniation: minimally invasive thoracic microdiscectomy.

Thoracic disc herniations are uncommon lesions that are asymptomatic in most patients; however, for individuals who present with persistent radiculopathy that is nonresponsive to conservative treatment or with myelopathic symptoms with or without radiculopathy attributed to a thoracic disc herniation, operative intervention of the thoracic spine is sought. Various procedures and approaches for the treatment of thoracic disc herniations have been reported, but they have been associated with numerous intraoperative complications and postoperative morbidities. This article discusses a novel minimally invasive procedure for the surgical treatment of thoracic disc herniations referred to as a minimally invasive thoracic microdiscectomy. It uses a series of muscle dilators, a tubular retractor, and microscopic visualization by way of a posterolateral approach in an effort to minimize many of the complications that are associated with the more traditional approaches.

The development of minimally invasive spine surgery.

The modern era of minimally invasive spine surgery has its roots in percutaneous techniques developed in the mid-twentieth century. The widespread application of minimally invasive techniques seen today is predicated on technologic developments of only the past 10 years, however. This article reviews the development of minimally invasive spinal surgery as it has evolved for the cervical, thoracic, and lumbar spine. Each new development has sought to equal or improve on the effectiveness demonstrated by comparable open surgical techniques while reducing iatrogenic tissue trauma and resultant postoperative pain and disability, to produce overall better outcomes for patients.

Endoscopic posterior cervical foraminotomy and discectomy.

Posterior cervical microendoscopic foraminotomy and discectomy is an effective minimally invasive approach to cervical radiculopathy caused by foraminal osteophytes or lateral disc herniations. This article reviews the technique in detail as well as the advantages over open approaches. Nuances of the technique, including complications and their management, are also explored.

Anterior cervical discectomy and corpectomy.

OBJECTIVE: The objective of this review article is to describe the authors' operative technique for performing anterior cervical corpectomy and fusion. METHODS: The authors reviewed their operative technique and experience to clearly detail the general methods utilized to safely and effectively perform anterior cervical corpectomy and fusion. Specific nuances peculiar to the authors' technique were identified and highlighted. RESULTS: The operative technique for anterior cervical corpectomy, including nuances for enhancing ease or outcome of surgery, is described in detail. Drawings and photographs are included where appropriate to highlight specific aspects of the procedural technique. CONCLUSION: Anterior cervical corpectomy and fusion is a well known technique that proceeds in a consistent and logical sequence of maneuvers. Specific technical nuances at various points enhance the ease and safety of the technique, as well as the completeness of the eventual result.

Thoracic microendoscopic discectomy.

OBJECT: Various approaches exist for the treatment of thoracic disc herniation. Anterior approaches facilitate ventral exposure but place the intrathoracic contents at risk. Posterolateral approaches require extensive muscle dissection that adds to the risk of postoperative morbidity. The authors have developed a novel posterolateral, minimally invasive thoracic microendoscopic discectomy (TMED) technique that provides an approach to the thoracic spine which is associated with less morbidity. METHODS: Seven patients 23 to 54 years old with nine disc herniations underwent TMED. All lesions were soft lateral or midline thoracic disc herniations. Under fluoroscopic guidance with the patient positioned prone, the authors used a muscle dilation approach and the procedure was performed with endoscopic visualization through a tubular retractor. Based on a modified Prolo Scale, five patients experienced excellent results, one good, and one fair. No case required conversion to an open procedure. The mean operative time was 1.7 hours per level, and estimated blood loss was 111 ml per level. Hospital stays were short, and no complications occurred. CONCLUSIONS: The TMED is safe, effective, and provides a minimally invasive posterolateral alternative for treatment of thoracic disc herniation without the morbidity associated with traditional approaches.

Review: complications of minimally invasive spinal surgery.

Complications of minimally invasive spinal surgery can be related to anesthesia, patient positioning, and surgical technique. The performance of successful minimally invasive spinal surgery is beset with several technical challenges, including the limited tactile feedback, two-dimensional video image quality of three-dimensional anatomy, and the manual dexterity needed to manipulate instruments through small working channels, which all account for a very steep learning curve. Knowledge of possible complications associated with particular minimally invasive spinal procedures can aid in their avoidance. This article reviews complications associated with minimally invasive spinal surgery in the cervical, thoracic, and lumbar spine by reviewing reported data of sufficient detail or with sufficient numbers of patients. In addition, possible complications associated with anesthesia use, patient positioning, and surgical techniques during thoracoscopic and laparoscopic spinal procedures are reviewed.

Microendoscopic lumbar discectomy: technical note.

OBJECTIVE: The microendoscopic discectomy (MED) technique was initially developed in 1997 to treat herniated lumbar disc disease. Since then, thousands of cases have been successfully performed at more than 500 institutions. This article discusses the technical aspects of this procedure and presents a consecutive case series. METHODS: A total of 150 consecutive patients underwent MED. MED is performed by a muscle-splitting approach using a series of tubular dilators with consecutively increasing diameters. A tubular retractor is then inserted over the final dilator, and a specially designed endoscope is placed inside the tubular retractor. The microdiscectomy is performed endoscopically while the surgeon views the procedure on a video monitor. RESULTS: Clinical outcomes were determined using a modified MacNab criteria, which revealed that 77% of patients had excellent, 17% had good, 3% had fair, and 3% had poor outcomes. The average hospital stay was 7.7 hours. The average return to work period was 17 days. Complications primarily included dural tears, which occurred in 8 patients (5%) and were seen early on in the patient series. Complication rates diminished as the surgeon's experience with this technique increased. CONCLUSION: MED for lumbar herniated disc disease can be performed safely and effectively, resulting in a shortened hospital stay and faster return to work; however, there is a learning curve to this procedure.