Thoracic Endovascular Aortic Repair for Iatrogenic Injury of the Thoracic Aorta

Purpose: Address iatrogenic injury to the descending thoracic aorta by breached spinal screws through a novel approach of concomitant spinal screw removal and thoracic endovascular repair (TEVAR) placement. Case Report: A 36-year-old female with idiopathic scoliosis underwent T4 to L3 bilateral pedicle instrumentation with spinal fusion and correction of scoliosis deformity. Ten months post-operative, she continued to complain of mid-thoracic pain; computed tomography (CT) angiography revealed protrusion of the left T5 and T6 transpedicular screws into her descending thoracic aorta by 3 and 5 mm, respectively. She was taken to the odds ratio (OR) in a combination case with vascular and neurosurgery. Positioned in the right lateral decubitus position, TEVAR was successfully deployed while neurosurgery concurrently removed the invading spinal screws via posterior spinal exposure. Neurosurgery then completely revised the spinal hardware during the same operation. The patient progressed well throughout the remainder of her hospital stay and was discharged on postoperative day 4. Two-year angiography demonstrated a well-placed TEVAR with no extravasation or aortic abnormality. Conclusions: In the setting of iatrogenic aortic injury due to pedicle screws, concomitant TEVAR and spinal screw removal is a safe and feasible treatment option that allows for spinal reconstruction to occur without multiple trips to the operating room.

An Anatomic Study of the Sural Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications

Background: The sural nerve (SN) is a sensory cutaneous nerve that is at risk of iatrogenic injury during surgery at the lateral ankle. Prior anatomic studies of the SN are limited primarily to cadaveric studies with small sample sizes. Our study analyzed a large cohort of magnetic resonance images (MRIs) of the ankle to obtain a more generalizable, in vivo sample of distal SN course. Methods: A total of 204 3-tesla MRI studies of the ankle were analyzed. Three reviewers measured the distance from the SN to various landmarks including the distal tip of the lateral malleolus (DTLM) and the lateral border of the Achilles tendon (LBA). Results: Mean vertical distance from SN to DTLM was 2.2 cm (range, 0.9-3.6 cm). Mean horizontal distance from SN to DTLM and to LBA at the level of DTLM was 1.7 cm (range, 0.8-3.0 cm) and 1.9 cm (range, 1.0-2.9 cm), respectively. Mean horizontal distance from SN to LBA at the level of superior Achilles tendon insertion onto the calcaneus (SAI) was 2.6 cm (range, 1.4-3.7 cm), and mean horizontal distance from SN to LBA at 5 cm above SAI was 0.9 cm (range, 0.4-1.8 cm). Conclusion: The variation in SN course observed in our study allowed us to propose “safe zones” for several surgical approaches including the extensile lateral approach to the calcaneus (ELAC), the sinus tarsi approach (STA), the direct lateral approach to the lateral malleolus (DLA), and the posterolateral approach to the ankle (PLA), which we hope will minimize iatrogenic injury to the SN. Level of Evidence: Level IV, case series.

3D model-assisted instrumentation of the pediatric spine: a technical note

Background Instrumentation of the pediatric spine is challenging due to anatomical constraints and the absence of specific instrumentation, which may result in iatrogenic injury and implant failure, especially in occipito-cervical constructs. Therefore, preoperative planning and in vitro testing of instrumentation may be necessary. Methods In this paper, we present a technical note on the use of 1:1 scale patient-specific 3D printed spinal models for preoperative assessment of feasibility of spinal instrumentation with conventional spinal implants in pediatric spinal pathologies. Results The printed 3D models fully matched the intraoperative anatomy and allowed a preoperative confirmation of the feasibility of the planned instrumentation with conventional screws for adult patients. In addition, the possibility of intraoperative model assessment resulted in better intraoperative sense of spinal anatomy and easier freehand screw insertion, thereby reducing the potential for iatrogenic injury. All 3D models were printed at the surgical department at a very low cost, and the direct communication between the surgeon and the dedicated specialist allowed for multiple models or special spinal segments to be printed for more detailed consideration. Conclusions Our technical note highlights the critical steps for preoperative virtual planning and in vitro testing of spinal instrumentation on patient-specific 3D printed models at 1:1 scale. The simple and affordable method helps to better visualize pediatric spinal anatomy and confirm the suitability of preplanned conventional spinal instrumentation, thereby reducing X-ray exposure and intraoperative complications in freehand screw insertion without navigation.

Accessory Palmaris Longus Encountered during Carpal Tunnel Surgery: A Case Report

The accessory palmaris longus is a rare anatomical variant in the wrist and forearm, which has been reported as the cause of carpal tunnel syndrome. This paper reports a case of the accessory palmaris longus incidentally found during carpal tunnel surgery. The paucity of awareness on the accessory palmaris longus in carpal tunnel surgery may lead to accidental iatrogenic injury to the median nerve or insufficient decompression of the median nerve.

Anatomical Configurations of Dominant Anastomotic Veins of the Superficial Cortical Venous System

Understanding the anatomy of the anastomotic veins (AV) of the superficial cortical venous system (SCVS), viz. superficial Sylvian vein (SSV) - also known as the superficial middle cerebral vein; vein of Labbe (VL) and vein of Trolard (VT), are imperative for neurosurgical procedures. This study aimed to investigate variant anatomical patterns of dominance of the AV, to elucidate the haemodynamically balanced SCVS, by reporting variations between the presence, diameter and dominant patterns of the AV. Two hundred lateral angiograms were included, depicting left and right cerebral hemispheres of the same patient (n = 100 patients). Angiograms were analysed and variations recorded. Results were statistically compared against laterality, age, sex and ethnicity. Presence of the VL had the highest occurrence (96.5%), whereas the SSV and VT had an occurrence of 75.5% and 64.5%, respectively. This study reports presence of double veins of the AV: SSV (12.0%), VL (22.0%) and VT (19.5%). Furthermore, presence of a triple vein for each AV is reported. Diameters for the SSV, VL and VT were 1.99 ± 0.500mm, 2.18 ± 0.579mm and 2.14 ± 0.472mm, respectively. Statistically significant relationships were established between diameters and the SSV, VL, VT and VT2 (double VT). Seven types of dominant patterns were recorded: Equilibrium; singular dominance of SSV, VL and VT; co-dominance of SSV/VL, SSV/VT and VL/VT. The Equilibrium dominant pattern of drainage had the highest occurrence (54.5%). Patterns of dominance of these AV can aid the neurosurgeon in curbing the risk of iatrogenic injury and postoperative infarcts even after an otherwise successful surgery.

DIVERSE ANATOMICAL CONFIGURATION OF ILIOINGUINAL NERVE IN RELATION TO LATERAL FEMORAL CUTANEOUS NERVE: A CASE REPORT

The variability in the formation of Ilioinguinal nerve has been documented in the literature especially related to iliohypogastric nerve. But so far very few cadaveric studies have been documented on variation in the branches of ilioinguinal nerve. A case presented which demonstrates aberrancy of its anatomic position. Although the course of ilioinguinal nerve has been well known, nostudies or report have demonstrated a course in relation to lateral femoral cutaneous nerve. This case report serves as a warning to the surgeon to be aware of such bizarre presentation since the consequences of iatrogenic injury to such structures may be serious.

TELD with limited foraminoplasty has potential biomechanical advantages over TELD with large annuloplasty: an in-silico study

Background Facetectomy, an important procedure in the in–out and out–in techniques of transforaminal endoscopic lumbar discectomy (TELD), is related to the deterioration of the postoperative biomechanical environment and poor prognosis. Facetectomy may be avoided in TELD with large annuloplasty, but iatrogenic injury of the annulus and a high grade of nucleotomy have been reported as risk factors influencing poor prognosis. These risk factors may be alleviated in TELD with limited foraminoplasty, and the grade of facetectomy in this surgery can be reduced by using an endoscopic dynamic drill. Methods An intact lumbo-sacral finite element (FE) model and the corresponding model with adjacent segment degeneration were constructed and validated to evaluate the risk of biomechanical deterioration and related postoperative complications of TELD with large annuloplasty and TELD with limited foraminoplasty. Changes in various biomechanical indicators were then computed to evaluate the risk of postoperative complications in the surgical segment. Results Compared with the intact FE models, the model of TELD with limited foraminoplasty demonstrated slight biomechanical deterioration, whereas the model of TELD with large annuloplasty revealed obvious biomechanical deterioration. Degenerative changes in adjacent segments magnified, rather than altered, the overall trends of biomechanical change. Conclusions TELD with limited foraminoplasty presents potential biomechanical advantages over TELD with large annuloplasty. Iatrogenic injury of the annulus and a high grade of nucleotomy are risk factors for postoperative biomechanical deterioration and complications of the surgical segment.

Accurate prenatal discrimination of placenta accreta spectrum from uterine dehiscence is necessary to ensure optimal management

Uterine scar dehiscence with underlying placenta is often misdiagnosed as placenta accreta spectrum both prenatally and intraoperatively due to the absence of myometrial tissue in the area. Misdiagnosis generates obstetric anxiety and results in overtreatment which carries a risk of iatrogenic injury. We present a case of the antenatal diagnosis of uterine dehiscence in a 36-year-old woman with a history of two caesarean deliveries and a low-lying placenta. We further describe the sonographic features useful for differentiating this condition from placenta accreta spectrum in instances where the placenta lies under an area of full thickness uterine scar dehiscence.