Demonstration of the Adamkiewicz Artery by Multidetector Computed Tomography Angiography Analysed with the Open-Source Software OsiriX

Risk Factors for Spinal Cord Injury during Endovascular Repair of Thoracoabdominal Aneurysm: Review of the Literature and Proposal of a Prognostic Score

Despite recent improvements, spinal cord ischemia remains the most feared and dramatic complication following extensive aortic repair. Although endovascular procedures are associated with a lower risk compared with open procedures, this risk is still significant and must be considered. A combined medical and surgical approach may help to optimize the tolerance of the spinal cord to ischemia. The aim of this review is to describe the underlying mechanism involved in spinal cord injury during extensive endovascular aortic repair, to describe the different techniques used to improve spinal cord tolerance to ischemia-including the prophylactic or curative use of spinal drainage-and to propose our algorithm for spinal cord protection and the rational use of spinal drainage.

Outcomes following Management of Complex Thoracoabdominal Aneurysm by an Open Approach

BACKGROUND

In the last decade, advances in surgical techniques, and the introduction of adjuncts for organ protection, have modified the approach for thoracoabdominal aortic aneurysm (TAAA) surgical repair. The aim of this study is to determine whether the contemporary approach influenced the outcomes.

METHODS

From 1989 to 2022, patients who had received elective open surgical repair (OSR) for TAAA at our institution were retrospectively analyzed. This series has been divided in two groups: Group 1 (1989-2009), and Group 2 (2010-2022). Patients included in Group 1 were those treated with a selective use of adjuncts, and Group 2 included patients treated with the systematic use of adjuncts.

RESULTS

A total of 1107 patients were treated (Group 1: 455; Group 2: 652). The surgical management was significantly different between the two groups. The in-hospital mortality was significantly different between the two groups (Group 1: 13.4%, Group 2: 8.1%; p 0.004), as was the rate of permanent spinal cord ischemia (Group 1: 11.9%, Group 2: 7.8%; p 0.023). Renal and respiratory failure were reduced in Group 2, but not significantly.

CONCLUSIONS

The use of the adjuncts enabled the achievement of improvement in mortality and SCI prevention in TAAA OSR. Although a refined surgical technique, mortality and morbidity are still noteworthy in this complex aortic field.

Anatomical study of the thoracolumbar radiculomedullary arteries, including the Adamkiewicz artery and supporting radiculomedullary arteries

OBJECTIVE

The aim of this paper was to identify and characterize all the segmental radiculomedullary arteries (RMAs) that supply the thoracic and lumbar spinal cord.

METHODS

All RMAs from T4 to L5 were studied systematically in 25 cadaveric specimens. The RMA with the greatest diameter in each specimen was termed the artery of Adamkiewicz (AKA). Other supporting RMAs were also identified and characterized.

RESULTS

A total of 27 AKAs were found in 25 specimens. Twenty-two AKAs (81%) originated from a left thoracic or a left lumbar radicular branch, and 5 (19%) arose from the right. Two specimens (8%) had two AKAs each: one specimen with two AKAs on the left side and the other specimen with one AKA on each side. Eight cadaveric specimens (32%) had 10 additional RMAs; among those, a single additional RMA was found in 6 specimens (75%), and 2 additional RMAs were found in each of the remaining 2 specimens (25%). Of those specimens with a single additional RMA, the supporting RMA was ipsilateral to the AKA in 5 specimens (83%) and contralateral in only 1 specimen (17%). The specimens containing 2 additional RMAs were all (100%) ipsilateral to their respective AKAs.

CONCLUSIONS

The segmental RMAs supplying the thoracic and lumbar spinal cord can be unilateral, bilateral, or multiple. Multiple AKAs or additional RMAs supplying a single anterior spinal artery are common and should be considered when dealing with the spinal cord at the thoracolumbar level.

Preoperative spinal angiography decreases risk of spinal ischemia in pediatric posterior thoracic tumor resection

PURPOSE

Resection of pediatric posterior thoracic tumors (PTTs) can be complicated by Artery of Adamkiewicz (AKA) injury. Post-op spinal ischemia occurs in approx. 3.2% of patients, typically due to iatrogenic vascular injury. Pre-op angiography (PSA) may help to avoid this complication. Herein, we aim to evaluate outcomes after initiation of routine PSA prior to PTT resection.

METHODS

A single-institution retrospective review identified 25 children (< 18 years) treated for PTTs from 2009 to 2021. PTTs included: posterior mediastinum, paraspinal thorax and posterior chest wall tumors. PSA patients were compared to those without pre-operative angiography (NA). Demographics, perioperative and long-term outcomes and event-free survival (EFS) were assessed.

RESULTS

Prior to 2012, eleven patients were treated without PSA. However, the last developed post-operative paraplegia secondary to spinal ischemia. Since this event, PSA has become routine for all PTTs (n = 14) identifying six AKAs and nine accessory spinal arteries. Resection was performed in ten (90.1%) NA patients and eight (57.1%) PSA patients. Based on PSA findings, resection was not offered to six patients and planned partial resection was performed in three patients. Five PSA patients required radiation therapy for local control vs two NA patients. There were no differences in recurrence or overall EFS.

CONCLUSION

PSA aids in identifying patients with high-risk thoracic vascular anatomy and may prevent risk of post-operative paraplegia associated with PTT resection.

Neurologic complications of diseases of the aorta

Neurologic complications of diseases of the aorta are common, as the brain and spinal cord function is highly dependent on the aorta and its branches for blood supply. Any disease impacting the aorta may have significant impact on the ability to deliver oxygenated blood to the central nervous system, resulting in ischemia-and if prolonged-cerebral and spinal infarct. The breadth of pathology affecting the aorta is diverse and neurologic complications can vary dramatically based on the location, severity, and underlying etiology. This chapter outlines the major pathology of the aorta while highlighting the associated neurologic complications. This chapter covers the entire spectrum of neurologic complications associated with aortic disease by beginning with a detailed overview of the spinal cord vascular anatomy followed by a discussion of the most common aortic pathologies affecting the nervous system, including aortic aneurysm, aortic dissection, aortic atherosclerosis, inflammatory and infectious aortopathies, congenital abnormalities, and aortic surgery.

Spinal Cord Ischemia Following Endovascular Repair of Infrarenal Abdominal Aortic Aneurysm

Spinal cord injury (SCI) following endovascular aortic repair (EVAR) for an abdominal aortic aneurysm (AAA) is a rare but serious complication. Case 1 presented with ruptured AAA and shock and underwent emergency EVAR. The patient developed incomplete paraplegia 2 days following EVAR. Case 2, diagnosed with impending rupture of AAA with extremely shaggy aorta, was treated with emergency EVAR. The patient was diagnosed with complete paraplegia soon after EVAR. Case 3 underwent elective EVAR and developed delayed paraplegia 2 weeks later. In EVAR, the etiology of SCI leading to paraplegia is often multifactorial. Surgeons must consider the possibility of SCI-induced paraplegia.

Spinal subarachnoid hemorrhage in type B aortic dissection: a rare presentation

Paraplegia is a common complication encountered during surgical and endovascular repair of aortic diseases. At times, it is also a presenting feature of aortic dissection. Involvement of more than one spinal blood supply system is the most common cause of spinal cord ischemia. Proper planning is needed to prevent and treat spinal cord ischemia. We report this rare case of acute type B aortic dissection that presented with paraplegia due to a spinal subarachnoid hemorrhage.

Identification of the Artery of Adamkiewicz Using Multidetector Computed Tomography Angiography (MCTA)

Objective  The aim of the present study is to evaluate the artery of Adamkiewicz by multidetector computed tomography angiography (MCTA) in a Brazilian population.

Methods  Two independent observers evaluated 86 coronary MCTA examinations. The variables studied included the identification of the artery of Adamkiewicz at its origin level, and its entry side in the spine.

Results  The artery of Adamkiewicz was detected in 71 (82.5%) examinations. The origin level was identified between the 9th and 11th thoracic vertebrae (T9 and T11) in 56 (79.2%) patients. In 65 (91.5%) patients, the artery was on the left side. The identification of the artery of Adamkiewicz using MCTA showed high reproducibility.

Conclusions  Our results were consistent with the literature regarding the identification of the artery of Adamkiewicz using MCTA, suggesting that this technique should be considered as an option to recognize this structure. In addition, we found that the distribution of the artery of Adamkiewicz in the Brazilian population is similar to that of other populations, that is, its most common origin is at the left side, between the 8th and 12th thoracic vertebrae (T8–T12).

Artery of Adamkiewicz: a meta-analysis of anatomical characteristics

PURPOSE

The artery of Adamkiewicz (AKA) provides the major blood supply to the anterior thoracolumbar spinal cord and iatrogenic injury or inadequate reconstruction of this vessel during vascular and endovascular surgery can result in postoperative neurological deficit due to spinal cord ischemia. The aim of this study was to provide comprehensive data on the prevalence and anatomical characteristics of the AKA.

METHODS

An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included study type, prevalence of the AKA, gender, number of AKA per patient, laterality, origin based on vertebral level, side of origin, morphometric data, and ethnicity subgroups.

RESULTS

A total of 60 studies (n = 5437 subjects) were included in the meta-analysis. Our main findings revealed that the AKA was present in 84.6% of the population, and patients most frequently had a single AKA (87.4%) on the left side (76.6%) originating between T8 and L1 (89%).

CONCLUSION

As an AKA is present in the majority of the population, caution should be taken during vascular and endovascular surgical procedures to avoid injury or ensure proper reconstruction. All surgeons operating in the thoracolumbar spinal cord should have a thorough understanding of the anatomical characteristics and surgical implications of an AKA.

Malignant Melanotic Schwannian Tumor Presenting with Spinal Cord Infarction Due to Occlusion of the Artery of Adamkiewicz: Case Report and Review of the Literature

BACKGROUND

Malignant melanotic schwannian tumors (MMSTs) are rare peripheral nerve sheath tumors that typically exhibit benign clinical presentation and histopathology but malignant long-term behavior.

CASE DESCRIPTION

We report a case of a 22-year-old male with a T9-11 MMST who presented with acute paraplegia and complete loss of sacral function. Despite emergent decompression, he did not recover motor, sensory or bladder function, although bowel function did normalize.

CONCLUSIONS

The anatomic location and rapid presentation of permanent deficits are suggestive of infarction of the spinal cord supplied by the artery of Adamkiewicz, a rare presentation of this disorder and of spinal schwannomas in general.

Desenvolvimento de modelo clínico para predição da possibilidade de identificação da artéria de Adamkiewicz por angiotomografia

Contexto

Diferenças morfológicas da artéria de Adamkiewicz (AKA) entre a população portadora e não portadora de doença aórtica têm importância clínica, influenciando as complicações neuroisquêmicas da medula espinhal em procedimentos operatórios. Ainda não é conhecida a correlação entre parâmetros clínicos e a previsibilidade da identificação dessa artéria pela angiotomografia.

Objetivo

Desenvolver um modelo matemático que, através de parâmetros clínicos correlacionados com aterosclerose, possa prever a probabilidade de identificação da AKA em pacientes submetidos a angiotomografias.

Método

Estudo observacional transversal utilizando banco de imagens e dados de pacientes. Foi feita análise estatística multivariada e criado modelo matemático logit de predição para identificação da AKA. Variáveis significativas foram utilizadas na montagem da fórmula para cálculo da probabilidade de identificação. O modelo foi calibrado, e a discriminação foi avaliada pela curva receiver operating characteristic (ROC). A seleção das variáveis explanatórias foi guiada pela maior área na curva ROC (p = 0,041) e pela significância combinada das variáveis.

Resultados

Foram avaliados 110 casos (54,5% do sexo masculino, com idade média de 60,97 anos e etnia com coeficiente B -2,471, M -1,297, N -0,971), com AKA identificada em 60,9%. Índice de massa corporal: 27,06 ± 0,98 (coef. -0,101); fumantes: 55,5% (coef. -1,614/-1,439); diabéticos: 13,6%; hipertensos: 65,5% (coef. -1,469); dislipidêmicos: 58,2%; aneurisma aórtico: 38,2%; dissecção aórtica: 12,7%; e trombo mural: 24,5%. Constante de 6,262. Fórmula para cálculo da probabilidade de detecção: (e−(Coef. Etnia+(Coef. IMC×IMC)+Coef.fumante+Coef.HAS+Coef.dislip+Constante)+1)−1 . O modelo de predição foi criado e disponibilizado no link https://vascular.pro/aka-model .

Conclusão

Com as covariáveis etnia, índice de massa corporal, tabagismo, hipertensão arterial e dislipidemia, foi possível criar um modelo matemático de predição de identificação da AKA com significância combinada de nove coeficientes (p = 0,042).

Ischaemia of the medullary cone after stent-graft implantation in a patient with abdominal aortic aneurysm - a case study

Preoperative visualization of the Adamkiewicz artery - the vessel which is to a great extent responsible for supplying blood to the medullary cone - is an important step which must be taken before initiating restorative procedures in the aorta. We present a case of a 67-year-old patient who underwent an intravascular stent-graft implantation procedure, due to clinical signs of abdominal aortic aneurysm. Routine pre-operative computed tomography examination failed to demonstrate the Adamkiewicz artery. On the second day after the surgery, as a result of unexpected clinical deterioration, an magnetic resonance imaging examination of the lumbar spine was carried out. Based on the magnetic resonance imaging images and clinical manifestations the diagnosis of ischaemia of the medullary cone was made. In our work we also present a deep analysis of the anatomy of small-sized vessels supplying blood to the spinal cord and discuss effective techniques which enable visualization of the Adamkiewicz artery.

Management of Thoracic Disc Herniations via Posterior Unilateral Modified Transfacet Pedicle-Sparing Decompression With Segmental Instrumentation and Interbody Fusion

STUDY DESIGN

Retrospective consecutive case series.

OBJECTIVE

The objective of this case series was to demonstrate the safety of a modified transfacet pedicle-sparing decompression and instrumented fusion in patients with thoracic disc herniations (TDHs).

METHODS

Consecutive patients undergoing operative management of TDH from July 2007 to December 2011 using a posterior unilateral modified transfacet pedicle-sparing approach were identified. All patients underwent open or minimally invasive modified transfacet pedicle-sparing discectomy and segmental instrumentation with interbody fusion, performed by four different surgeons. Pre- and postoperative visual analog scale (VAS) pain scores, Nurick grade, and American Spinal Injury Association Impairment Scale (AIS) were analyzed from a retrospective chart review. Estimated blood loss and complications were also obtained.

RESULTS

Fifty-one patients were included that had operations for TDH. Thirty-nine patients had single level decompression and 12 had multilevel decompression. The total number of levels operated on was 64. Five patients were treated with minimally invasive surgery. A herniated disc level of T11-12 (n = 17) was treated most often. One major complication of epidural hematoma occurred. Minor complications such as malpositioned hardware, postoperative hematoma, wound infection, pseudoarthrosis, and pulmonary complications occurred in a few patients. Follow-up ranged from 1 to 46 months with 1 patient lost to follow-up. From preoperative to final postoperative: mean VAS scores improved from 8.31 to 4.05, AIS in all patients remained stable or improved, and Nurick scores improved from 3 to 2.6 on average. No intraoperative or permanent neurological deficit occurred.

CONCLUSION

In our surgical series, 51 consecutive patients underwent modified transfacet pedicle-sparing approach to TDHs and experienced improvement of functional status as well as improvement of objective pain scales with no neurological complications. The posterior unilateral modified transfacet pedicle-sparing decompression and instrumented fusion approach to the thoracic spine is a safe and reproducible procedure for the treatment of TDHs.

Spinal cord anteroposterior atrophy in HAM/TSP: Magnetic resonance imaging and neuropathological analyses

To evaluate the spinal cord atrophy that occurs in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), we conducted magnetic resonance imaging (MRI) and pathological analyses. In the MRI study, 15 patients with HAM/TSP and 20 age-matched normal control subjects were enrolled. Anteroposterior and transverse distances and cross-sectional areas were measured and calculated at the C2, C4, C6, T2, and T6 vertebral levels. In the pathological study, spinal cord autopsy specimens were compared between a HAM/TSP case and an adult T cell leukemia/lymphoma case. In both the MRI and pathological studies, HAM/TSP spinal cords demonstrated more severe atrophy in the anteroposterior direction than those of controls. The spinal cord atrophy and pathological changes in HAM/TSP occurred predominantly in the white matter, especially in the lateral columns. This is the first report indicating spinal cord atrophy in the anteroposterior direction using MRI. In pathological analysis, atrophy and pathological changes were prominent in areas of the spinal cord with slow blood flow. Hemodynamic and anatomical factors are speculated to be among the main mechanisms of atrophy in the anteroposterior direction.

Predictors of Adamkiewicz artery and anterior spinal artery detection through computerized tomographic angiography

Background:

The detection of the Adamkiewicz artery and the anterior spinal artery has been associated with the ability to prevent adverse spinal cord outcomes after aortic surgical procedures. Yet, to our knowledge, no previous studies have attempted to use modern predictive models to identify the most important variables in determining artery detectability.

Aims:

To develop a model to predict the odds of visualizing the Adamkiewicz artery or anterior spinal artery in patients undergoing computerized tomographic angiography.

Methods:

We conducted a prospective, cross-sectional study. Outcomes of interest were the non-detection of the Adamkiewicz artery and anterior spinal artery, and their corresponding level of origin. Axial images were inspected in high definition in search of two dense spots characterizing the Adamkiewicz artery and anterior spinal artery. A multiplanar three-dimensional reconstruction was then performed using the OsiriX® software.

Results:

A total of 110 participants were part of this analysis. When evaluating risks for the Adamkiewicz artery being undetectable, significant factors could be classified into three broad categories: risk factors for arterial disease, established arterial disease, and obesity. Factors in the former category included metabolic syndrome, hypertension, and smoking status, while factors in the arterial disease included descending aortic aneurysm, mural thrombi, aortic aneurysm without a dissection, and aortic disease in general. In relation to anterior spinal artery not being detectable, significant risk factors included hypertension, smoking status, and metabolic syndrome, while those associated with arterial disease involved aortic disease and arterial thrombi. When evaluating the importance of individual clinical factors, the presence of higher body mass index was the single most important risk factor.

Conclusion:

Arterial disease, established arterial disease, and increased body mass index are risk factors in the detection of Adamkiewicz artery and anterior spinal artery. Specific diagnostic protocols should be in place for patients with these underlying conditions, thus enhancing the likelihood of detection when the Adamkiewicz artery is indeed present.

Vestibulo-Oral inclination of maxillary and mandibular canines and bicuspids - a CBCT investigation

BACKGROUND

The aim of this retrospective study was to measure tooth and crowns axes of canines, first and second bicuspids of orthodontically untreated subjects with near normal occlusion to: 1. Define norms and reveal potential gender differences and 2. Discuss implications of the findings for orthodontics.

METHODS

The CBCT-datasets of 167 patients, 56 males (mean age 28.63 years ± 11.99 years) and 111 females (mean age 29.72 years ± 11.47 years) were used. Tooth- and crown axes were measured for right and left sides. Normal distribution was evaluated with the Kolmogorov-Smirnov-test. For gender comparison independent t-Tests and for comparison of right and left sides a paired t-Test were used for normally distributed data. For data not following normal distribution for gender comparison the Mann-Whitney-U-Test was used and for data comparing the two sides the Wilcoxon signed rank test was applied. The level of statistical significance was set at p ≤ 0.05.

RESULTS

Measurement of tooth axes revealed buccal inclination for both genders with maximum values for maxillary and mandibular canines. Statistical significant differences were only found for maxillary canines (P = 0.025) and lower second bicuspids (P = 0.016) respectively. Values for crown axes revealed oral inclination for both genders with maximum values for maxillary first bicuspids and in the mandible for first and second bicuspids. No statistical significant differences were found between the genders apart from asymmetry for crown axes for the upper first bicuspids for males (P = 0.006) and females (P < 0.001).

CONCLUSIONS

Our study reveals that irrespective of gender, oral inclination of the crowns of canines and premolars is the norm. The values of the most commonly used bracket prescriptions coincide with the average values found in our investigation. For esthetic reasons modifications of torque values can be considered.

Three dimensional anatomical exploration of the anterior hard palate at the level of the third ruga for the placement of mini-implants--a cone-beam CT study

AIM

The aim of this retrospective investigation was to measure vertical bone thickness on the hard palate, determine areas with adequate bone for the insertion of orthodontic mini-implants (MIs), and provide clinical guidelines for identification of those areas.

MATERIALS AND METHODS

Pre-treatment records of 1007 patients were reviewed by a single examiner. A total of 125 records fulfilled the inclusion criteria and were further investigated. Bone measurements were performed on cone-beam computed tomography scans, at a 90° angle to the bone surface, on 28 predetermined and standardized points on the hard palate. Bone thickness at various areas was associated to clinically identifiable areas on the hard palate by means of pre-treatment plaster models.

RESULTS

Bone thickness ranged between 1.51 and 13.86 mm (total thickness) and 0.33 and 1.65 mm (cortical bone thickness), respectively. Bone thickness was highest in the anterior palate and decreased significantly towards more posterior areas. Plaster model analysis revealed that bone thickness was highest at the level of the third palatal ruga.

CONCLUSIONS

The areas on the anterior palate with adequate bone thickness for successful insertion of orthodontic MI correspond to the region of the third palatal ruga. These results provide stable and clinically identifiable landmarks for the insertion of palatal MIs.

An integrated teaching method of gross anatomy and computed tomography radiology

It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench-side (OsiriX on iPod touch or iPad), which enabled "pixel-to-tissue" direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses.

Immediate and Late Outcomes of Bronchial and Systemic Artery Embolization for Palliative Treatment of Patients With Nonsmall-Cell Lung Cancer Having Hemoptysis

Background:

Hemoptysis in patients with advanced lung cancer can be a life threatening.

Objectives:

To evaluate immediate outcomes and late outcomes of bronchial artery embolization (BAE) for palliative treatment in patients with advanced nonsmall-cell lung cancer (NSCLC) having hemoptysis.

Methods:

The BAE was performed in 28 patients with NSCLC. Hemoptysis was defined as follows: massive bleeding greater than 300 mL within 24 hours (n = 8), moderate bleeding of 100 to 300 mL within 24 hours (n =12), and slight bleeding less than100 mL within 24 hours (n = 8).

Results:

Success rate was 96%. Immediate clinical success within 24 hours after BAE was achieved in 22 of the 27 patients who underwent embolization.

Conclusions:

The BAE with gelatin sponge particles can provide good management of hemoptysis as a palliative treatment in patients with advanced NSCLC.

[Mediastinal localization of a growing teratoma syndrome: a case report]

The development of testicular germ cell tumors may be marked by a rare phenomenon: the growing teratoma syndrome. It consists of residual masses, usually retroperitoneal and, more rarely, thoracic, that appear during or after chemotherapy, although the tumor markers are normalized. We report a case of posterior mediastinal localization. This mediastinal localization is very rare, and because of the proximity to intercostal arteries, induces a risk of postoperative paraplegia.

Neurologic complications of aortic diseases and aortic surgery

Aortic disease processes have a wide range of clinical manifestations. The inflammatory disease process of Takayasu's arteritis differs dramatically from the visceral ischemia of aortic dissection. The catastrophic event of aortic rupture tends to overshadow life-altering events such as stroke and paraplegia. However, these neurologic manifestations of aortic diseases have dramatic effects that extend beyond the individual patient to include both social and financial ramifications. This chapter focuses on the major aortic disease processes and how they can initiate, both directly and indirectly, adverse neurologic events. The chapter concludes with a brief discussion of aortic surgery, how interventions on the aorta can cause neurologic complications, and techniques to avoid these feared adverse neurologic outcomes.

The vascular supply to the spinal cord and its relationship to anterior spine surgical approaches

BACKGROUND CONTEXT

The understanding of vascular supply to the spinal cord is important given that the evolution of surgical approaches to the spine may bring along the potential for more frequent complications, especially a rare but devastating complication: that of spinal cord ischemia or infarction. To maximally avoid this complication, the relationship between the spinal cord vascularity and the anterior spine surgical approach needs further study.

PURPOSE

To provide a theoretical basis that will allow the spinal surgeon to take appropriate steps to avoid spinal cord ischemia during anterior spinal surgery through anatomic means.

STUDY DESIGN

Spinal cord vascular casting assessment with cadaveric specimen.

METHODS

Twenty adult cadaveric specimens (11 men and 9 women) were obtained for the latex perfusion and vessel dissection. In addition, nine patients (seven men and two women) underwent superselective angiography of the spinal cord. The segmental arterial anastomosis and radiculomedullary vessels in the thoracolumbar region were shown and reviewed.

RESULTS

There were approximately 21 pairs of segmental arteries in the thoracolumbar region. Adjacent segmental arteries were networked with each other. The latex infusion specimens demonstrated 72 anterior radiculomedullary arteries and 177 posterior radiculomedullary arteries in all 20 samples. The anterior and posterior spinal arteries were also networked with each other at several levels. Superselective spinal angiography was consistent with the latex infusion specimens showing.

CONCLUSIONS

The variety of anatomy of spinal cord arterial networks is shown, and the relation between the blood supply of certain spinal levels and the potential ischemic complications during the anterior surgical approach is discussed. It is hopefully of benefit to surgeons, after fully understanding the anatomy of these spinal vascular supply structures, that there may be even greater avoidance of vascular compromise in these challenging operations.

Non-invasive vascular imaging in perforator flap surgery

Preoperative imaging using a range of imaging modalities has become increasingly popular for preoperative planning in plastic surgery, in particular in perforator flap surgery. Modalities in this role include ultrasound (US), magnetic resonance angiography (MRA), and computed tomographic angiography (CTA). The evidence for the use of these techniques has been reported in only a handful of studies. In this paper we conducted a non-systematic review of the literature to establish the role for each of these modalities. The role of state-of-the-art vascular imaging as an application in perforator flap surgery is thus offered.

Accuracy and reliability of length measurements on three-dimensional computed tomography using open-source OsiriX software

There is a growing interest in three-dimensional computed tomography (3D-CT) as a research tool for the study of bone, joint anatomy, and kinematics. However, when CT data are processed and handled manually using image processing programs to yield 3D image and coordinate value, systematic and random errors should be validated. We evaluated the accuracy and reliability of length measurement on CT with OsiriX software. 3D-CT scans were made of 14 frozen pig knees with five transosseous holes in the metaphyseal portion of femur. The lengths between tunnel orifices were measured using Mitutoyo Digimatic digital calipers to establish the gold standard, and with the OsiriX program in 3D multi-planar reformatting mode for comparison. All measurements were recorded by a principal (replicate 1, trial 1) and a secondary observer (replicate 2, trial 1) and were repeated once by each observer (trial 2). The mean differences between OsiriX and real measurements were less than 0.1 mm in both replicates, and maximum differences were less than 0.3 mm. There were no significant differences between the replicates and real measurements (p=0.544 and 0.622 for replicates 1 and 2, respectively). The intraclass correlation coefficients (ICC) were very high between trials and between replicates (ICC=0.998 and 0.999, respectively). For kinematic analysis of the knees, length measurements on 3D-CT using OsiriX program can be used as alternatives to real measurements with less than 0.3-mm accuracy and very high reliability.

Spinal cord ischemia after endovascular repair of infrarenal abdominal aortic aneurysm: a rare complication

Neurologic deficit secondary to spinal cord ischemia after elective infrarenal, endovascular aneurysm repair (EVAR), consists a rare and rather disastrous complication. The etiology of such neurologic complication seems to be multifactorial, making this event unpredictable and foremost unpreventable. We report a case of paraparesis and bladder dysfunction that occurred immediately after the EVAR procedure. Prompt management by conservative or invasive methods seems to be important for the reversal of the neurologic deficit and the optimization of patient's outcome.

Efficacy and reliability of highly functional open source DICOM software (OsiriX) in spine surgery

We evaluated the feasibility and reliability of open source Digital Imaging and COmmunication in Medicine (DICOM) imaging software, OsiriX (Antoine Rosset, 2003-2009), in spine surgery. CT data were used and processed with OsiriX and with commercial software for comparison. Images were reconstructed and compared in volume rendering (VR) and multi-planar reconstruction (MPR) mode. When all images were compared, the three-dimensional (3D) reconstructed images from both software packages showed considerable consistency in VR mode. Measurements in MPR mode also showed similar values with no statistically significant difference. These results demonstrate that OsiriX has approximately equivalent values to commercial software and provides reliable preoperative 3D information for the surgical field. In addition, any clinician, can obtain information using OsiriX at any time. Thus, OsiriX is a helpful tool in preoperative planning for spine surgery.

Advances in imaging of the spinal cord vascular supply and its relationship with paraplegia after aortic interventions. A review

INTRODUCTION

Preoperative knowledge of the spinal cord (SC) vasculature could be useful for stratifying and decreasing the risk of perioperative paraplegia after thoracic and thoraco-abdominal aortic surgery. Recent advances in magnetic resonance (MR) and computed tomography (CT) angiography and post-processing techniques have improved this knowledge.

METHODS

A search of MEDLINE/Pubmed and SCOPUS databases identified 1414 pertinent abstracts; 123 full-length manuscripts were screened to identify relevant studies with acceptable design and patient numbers. Forty-three were selected.

RESULTS

SC circulation was studied in 1196 patients to detect the great radicular artery: 522 by MR-angiography and 674 by CT angiography. Detection rates were 67-100% (mean 80.8%) with MR-angiography being 18-100% (mean 72%) with CT angiography. The side and level of the great radicular artery were consistent between the methods. Several authors tried to use the imaging results to guide clinical management.

CONCLUSIONS

Non-invasive imaging of the SC blood supply allows preoperative definition of the vasculature in many, but not all, cases. The impact of these findings on clinical management is potentially beneficial but still uncertain. Further improvements in image acquisition and post-processing techniques are needed. Future studies need to be large enough to compensate for inter-individual variability in SC vasculature in health and disease; however, even a partial reduction of paraplegia rate offers a formidable motivation for further research in this area.