Landmark For Dissection Research Articles

Laparoscopic Colorectal Surgery with Anatomical Recognition with Artificial Intelligence Assistance for Nerves and Dissection Layers

BackgroundIn digestive tract surgery, dissection of an avascular space consisting of loose connective tissue (LCT) appearing by countertraction improves oncological outcomes and reduces complications.1–3 Kumazu et al.4 described a deep learning approach that automatically segments LCT to help surgeons.4 During left colorectal surgery, lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries cause sexual dysfunction and/or urinary issues.5 As nerve preservation is critical for functional preservation, the AI model Kumazu reported is named Eureka (Anaut Inc., Tokyo, Japan) and was developed to separate nerves automatically. The educative efficacy of intraoperative nerve visualization has been described.6 Artificial intelligence (AI) assisted navigation is expected to aid in the anatomical recognition of nerves and the safe dissection layers surrounding nerves in the future.MethodsWe used Eureka as an educational tool for surgeons’ training during laparoscopic colorectal surgery. The laparoscopic system used was Olympus VISERA ELITE3 (Tokyo, Japan).ResultsTotal mesorectal excision (TME) was safely performed with nerve preservation. No postoperative complications occurred. Automatic segmentation and highlighting of LCT in the dissected layers, lumbar splanchnic, hypogastric, and pelvic visceral nerves (S3, S4), were performed in real time.ConclusionsIn colorectal cancer surgery, the nerves are vital anatomical structures serving as landmarks for dissection. Lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries (S3, S4) cause sexual dysfunction or urinary disorders.5 Nerve preservation is important for functional preservation. AI-assisted navigation methods are noninvasive, user-friendly, and expected to improve in accuracy in the future. They have the potential to develop nerve-guided TME.

7585 A Systematic Approach to Endometriosis Lesion Mapping and Radical Excision

<h3>Study Objective</h3> To illustrate a systematic approach to laparoscopic endometriosis lesion mapping and radical wide field excision. Significant variation exists regarding the optimal approach to surgical management of endometriosis with attempts for standardization being fairly recent. We hereby contribute to these efforts by presenting our approach to radical, wide-field endometriosis excision in our institution. <h3>Design</h3> Edited surgical video demonstrating laparoscopic radical wide field endometriosis excision. <h3>Setting</h3> Academically affiliated community hospital. <h3>Patients or Participants</h3> Surgical videos of multiple surgical cases from our practice <h3>Interventions</h3> Laparoscopic radical wide field excision of endometriosiss. <h3>Measurements and Main Results</h3> As illustrated in this video, important considerations are the non-contact, mm by mm dissection along the avascular planes, use of the perirectal tissue fat as an insulator and landmark for dissection, as well as the deliberate use of rectal and vaginal probes in order to delineate anatomy and optimize dissection geometry. <h3>Conclusion</h3> With a systematic approach to radical wide field excision of endometriosis, both in high and low ASRM stage disease, via a lateral to medial approach and clockwise progression from the left pelvic brim to the left pelvic sidewall and so on, virtually all cases will be completed safely and efficiently.

Intraoperative Observation during Total Extraperitoneal Repair (TEP)

We aim to observe and dissect the essential anatomical landmarks in totally extraperitoneal (TEP) procedures. Forty-six TEP procedures in 30 patients were prospectively performed in our department. During the dissection of the preperitoneal space, the following distances between landmarks were measured. D1: the distance from pubic symphysis to the arcuate line in the midline; D2: the distance from the inferior epigastric artery to the lateral border of the arcuate line (before sharp incision was performed); D3: as in D2 (but after sharp incision was performed); D4: the distance from the inferior epigastric artery to the crossing site of vas deferens and obliterated umbilical artery. Furthermore, the morphology of the posterior rectus sheath was documented. The corresponding distance between the anatomical landmarks varied greatly in each individual. D1: 8 ± 1.6 cm (range 4-10 cm). D2: 4.9 ± 0.8 cm (3.5-7 cm). D3: 6.8 ± 0.9 cm (5-9 cm). D4: 6.1 ± 1 cm (4.8-8.5 cm). Complete rectus sheath was found in 30.4 per cent (14/46) of the hernias. Anatomical variations were common in preperitoneal space. The crossing site of vas deferens and obliterated umbilical artery can serve as a landmark for dissection. Complete rectus was present in one-third of hernias, which necessitates a sharp incision for entering the correct lateral preperitoneal space.

The Endoscopic Endonasal Approach to the Hypoglossal Canal: The Role of the Eustachian Tube as a Landmark for Dissection.

Improvements in endoscopic technology and reconstructive techniques have made the endoscopic endonasal approach (EEA) a viable option to approach ventromedial lesions in the region of the hypoglossal canal. Prior to contemplating this surgical corridor, a thorough understanding of anatomic relationships and landmarks is essential to safely approach this region of the posterior skull base through an EEA. To describe the surgical technique and anatomic landmarks in the EEA to the hypoglossal canal through referencing nasopharyngeal and posterior skull base anatomy. Study of latex-injected cadaveric heads at the North Carolina Eye Bank Multidisciplinary Surgical Skills Laboratory at the University of North Carolina. An EEA to the hypoglossal canal was carried out bilaterally in 5 embalmed, latex-injected cadaver heads. Cadaveric measurements of anatomic landmarks and relationships in the approach were obtained using a 10-cm surgical ruler and were reported as mean distances. Additionally, high-quality endoscopic images demonstrating the operative technique and anatomic relationships were obtained. The distance between the lacerum segment of the internal carotid arteries, the superolateral boundary, was 23.6 mm (SD, 11.8 mm). The distance between the anterolateral edge of the occipital condyles, the inferolateral boundary, was 19 mm (SD, 0.80 mm). The supracondylar groove was identified in the same anteroposterior plane as the nasopharyngeal orifice of the eustachian tube, and the anterior-most edge of the occipital condyle was 14 mm (SD, 0.82 mm) from the posterosuperior edge of the salpingopharyngeal fold. Additionally, the transtubercular corridor was on the same plane as the superior edge of the torus tubarius in the anteroposterior axis. The distance to the hypoglossal canal from midline was 10 mm, which was found after completing drilling in the transcondylar and transtubercular corridors. Last, the hypoglossal nerve rootlets were identified entering the canal 6 mm inferiorly and 8 mm laterally from the vertebrobasilar junction. The eustachian tube and other elements of nasopharyngeal anatomy are fixed landmarks that provide important points of reference when approaching the hypoglossal canal through an EEA. A thorough understanding of these anatomic relationships is vital in safely navigating this direct, surgical corridor to the posterior fossa.

The Endoscopic Endonasal Approach to the Hypoglossal Canal: The Role of the Eustachian Tube as a Landmark for Dissection

The Endoscopic Endonasal Approach to the Hypoglossal Canal: The Role of the Eustachian Tube as a Landmark for Dissection

Anatomy of the middle temporal vein: implications for skull-base and craniofacial reconstruction using free flaps.

Finding appropriate recipient veins for free flap reconstruction in the adjacent temporal region is sometimes difficult when performing skull base or craniofacial reconstruction because there is a limited number of recipient veins in the temporal region compared with the neck. The authors used cadaver dissection to evaluate the viability of the middle temporal vein as a recipient vein in the temporal region. The authors examined the characteristics and landmarks of the middle temporal vein in 60 sides of 30 cadavers. Its existence, caliber size, distribution pattern, and landmarks for dissection were measured. The middle temporal vein was located beneath the superficial layer of the deep temporal fascia and joined the main trunk of the superficial temporal vein. The vein was identified in all specimens, and its mean caliber was 1.88 mm. It was classified into four representative distribution patterns. According to the distribution pattern, the middle temporal vein provided one recipient vein without exception, and only 13 percent of middle temporal veins could provide two recipient veins. According to landmarks, the middle temporal vein runs approximately along the line between 52 mm lateral from the bony lateral canthus and 12 mm medial from the external auditory canal. The mean distance between the middle temporal vein and the temporal branch of the facial nerve was 13 mm. The middle temporal vein can provide one recipient vein of adequate caliber in the temporal region. In addition, it can be easily localized, without damaging the facial nerve, by means of incision according to the landmarks described in this study.

A simple procedure to facilitate chin implants placement via submental approach

In order to facilitate chin implants placement by submental incision, the use of two threads is described. They are separately passed through the extremities of the implant and inserted into the previously created subperiosteal pocket using a grooved guide. Once the landmarks of dissection have been reached, the tip of the needle exits through the skin just a few centimetres laterally to the augmentation area and, only by pulling the free ends of the threads, the implant can easily be inserted into the pocket and the sutures cut and removed. This procedure was successfully performed in 79 patients of both sexes presenting with deficiencies in the sagittal dimension at the pogonion and in width, laterally to the symphysis. Therefore, in the authors' opinion, the before-described technique could be a useful tool that facial plastic surgeons can employ to facilitate alloplastic chin implants placement, by minimising the invasiveness of the procedure, reducing the operative time, and greatly improving the aesthetic result, without sacrificing the safety of the operation.

Endoscopic Anatomy of the Palatovaginal Canal (Palatosphenoidal Canal): A Landmark for Dissection of the Vidian Nerve during Endonasal Transpterygoid Approaches

Endoscopic Anatomy of the Palatovaginal Canal (Palatosphenoidal Canal): A Landmark for Dissection of the Vidian Nerve during Endonasal Transpterygoid Approaches

Extensive dissection at the porta hepatis for biliary atresia

Dissection at the porta hepatis is the crucial step in surgery for biliary atresia. The authors describe their procedure for extensively dissecting the porta hepatis. The technique is based on an anatomic cast corrosion of the human liver, and the portal vein serves as the landmark for dissection. Lateral dissection at the hepatic hilus is critical to the procedure. On the right side, the anterior portal branches are dissected to the bifurcation of the S 5 and S 7 segmental portal branches, over the bifurcation of the anterior and posterior portal branches. On the left side, the liver parenchyma, which bridges the umbilical point, is sectioned, and the left portal branch is dissected to the umbilical point over the pars transversalis and taped. The fibrous mass that lies within the confines of the portal branches, including the dorsal aspect, is transected completely. This procedure was performed in 16 infants; the jaundice cleared in 93.7%.