The Lone Star Retractor System in Neurosurgery

3-Dimensional Printed Model of the Temporal Bone for Neurosurgical Training

BACKGROUND AND OBJECTIVES

The development of neurosurgical skills stands out as a paramount objective for neurosurgery residents during their formative years. Mastery of intricate and complex procedures is a time-intensive process marked by a gradually ascending learning curve. Consequently, the study and simulation on surgical models assume significant importance. One of the most intricate neuroanatomical regions includes the petrous and mastoid portions of the temporal bone. These regions host critical, highly functional, and vital neurovascular structures, including the facial nerve, cochlea, semicircular canals, internal carotid artery, and middle ear. This fully open-source 3-dimensional (3D) model of the temporal bone, created for educational purposes, should be easily and economically reproducible using a 3D printer, offering all residents the opportunity to understand the spatial location, three-dimensional anatomical structures, and fundamental intricacies of mastoidectomy.

METHODS

A 3D model of the temporal bone was fabricated using a computed tomography (CT) scan derived from an actual human body. The CT scan of the model was meticulously juxtaposed with the reference sample CT scan. Neurosurgical residents were recruited as participants for this study. Each participant was tasked with executing a mastoidectomy on 2 separate occasions, with a 2-week interval between attempts. Throughout these sessions, various parameters, including the time taken for task completion, the volume of bone removal, and any potential complications, were systematically registered.

RESULTS

The mean volume of bone removed increased by 34.5%, and the mean task time and the mean number of complications decreased by 10.3% and 25%, respectively, during the training.

CONCLUSION

Engaging in training with cost-effective anatomical models constitutes a valuable tool for refining technical skills during residency. We posit that this type of model training should be incorporated as part of the trainee's curriculum during the residency program because of the myriad advantages evidenced by the findings of this study.

Lone-Star retractor perineal exposure method for laparoscopic abdominal perineal resection of rectal cancer

BACKGROUND

The abdominal perineal resection (APR), historically referred to as Mile's procedure, stands as a time-honored surgical intervention for rectal cancer management. Advancements in surgical techniques and the advent of neoadjuvant therapies have significantly improved the rate of sphincter preservation among patients afflicted with rectal cancer, including those with ultralow rectal cancer. Despite these improvements, APR maintains its irreplaceable role in the clinical landscape, particularly for cases involving low rectal cancer with encroachment on the external anal sphincter or levator ani muscles. Optimal perineal exposure stands as a pivotal phase in APR, given that the precision of this maneuver is directly correlated with both the safety of the surgery and the patient's subsequent long-term prognosis.

AIM

To evaluate the value of Lone-Star retractor (LSR) perineal exposure method in the treatment for laparoscopic APR of rectal cancer.

METHODS

We reviewed the records of 38 patients with rectal cancer at Anqing Municipal Hospital from January 2020 to December 2023, including 20 patients who underwent the APR procedure with a LSR perineal exposure method (LSR group) and 18 patients who underwent the APR procedure with a conventional perineal exposure method (control group). In the LSR group, following incision of the skin and subcutaneous tissue, the LSR was placed and dynamically adjusted according to the surgical plane to fully expose the perineal operative field.

RESULTS

A total of 38 patients underwent laparoscopic APR, none of whom were found to have distant metastasis upon intraoperative exploration. Perineal blood loss, the postoperative hospital stays and the wound pain scores in the LSR group were significantly lower than those in the control group. A single surgeon completed the perineal operation significantly more often in the LSR group than in the control group (P < 0.05). The incidence of infection via the perineal incision in the LSR group was significantly lower than that in the control group (P < 0.05). No cases of distant metastasis or local recurrence were found among the patients at the postoperative follow-up.

CONCLUSION

The application of the LSR technique might be helpful for performing perineal exposure during APR for rectal cancer and could reduce the incidence of perineal complications, shorten the postoperative hospital stay, improve postoperative pain, and allow one surgeon to perform the perineal operation.

The Course of the Trochlear Nerve Presented via a 3-Dimensional Photorealistic Anatomic Model

OBJECTIVES

Several factors contribute to the anatomical complexity of the trochlear nerve, including small diameter, complex and longest intracranial course, deep location, and numerous neurovascular relationships. A 3-dimensional (3D) photorealistic model of the cranial nerves provides a detailed and immersive representation of the anatomy, enabling one to improve surgical planning, advanced surgical research, and training. The purpose of this work is to present a 3D photogrammetric study for a more intuitive and interactive way to explore and describe the entire course of trochlear nerve.

METHODS

Two injected-fixed head human specimens (4 sides) were examined. The dissection protocol was divided into the following steps: 1) brain hemisphere exposure; 2) hemispherectomy dissecting all cranial nerves and partial removal of the free edge of the tentorium; 3) middle fossa and lateral wall of cavernous sinus exposure; and 4) orbital exposure. A detailed 3D photogrammetric model was generated for each dissection step.

RESULTS

Four main volumetric models were generated during a step-by-step layered dissection of the entire nerve pathway highlighting its different segments. Finally, a full and integrated model of the entire course of the nerve was created. The models are available for visualization on monoscopic display, virtual, and augmented reality environment.

CONCLUSIONS

The present photogrammetric model provides a more comprehensive understanding of the nerve's anatomy in its different segments, allows for customizable views thus simulating different perspectives, and can be a valuable alternative to traditional dissections. It is an advanced tool for surgical planning and surgical simulation as well as virtual reality representation of the anatomy.

A novel perineal exposure method in laparoscopic abdominal perineal resection of rectal cancer: a case series study

BACKGROUND

Abdominal perineal resection (APR) of rectal cancer, also known as Mile's procedure, is a classic procedure for the treatment of rectal cancer. Through the improvement of surgical skills and neoadjuvant therapy, the sphincter-preserving rate in rectal cancer patients has improved, even in patients with ultralow rectal cancer who underwent APR in the past. However, APR cannot be completely replaced by low anterior resection (LAR) in reality. APR still has its indications, when the tumor affects the external sphincter, etc. Good perineal exposure in APR is difficult and can seriously affect surgical safety and the long-term prognosis.

METHODS

We reviewed the records of 16 consecutive patients with rectal cancer who underwent APR at Anqing Municipal Hospital from January 2022 to April 2023, including 11 males and 5 females, with an average age of 64.8 ± 10.3 years. The perineal operation was completed with the Lone-Star® retractor-assisted (LSRA) exposure method. After incising the skin and subcutaneous tissue, a Lone-Star® retractor was placed, and the incision was retracted in surrounding directions with 8 small retractors, which facilitated the freeing of deep tissues. We dynamically adjusted the retractor according to the plane to fully expose the surgical field.

RESULTS

All 16 patients underwent laparoscopic-assisted APR successfully. Thirteen procedures were performed independently by a single person, and the others were completed by two persons due to intraoperative arterial hemostasis. All specimens were free of perforation and had a negative circumferential resection margin (CRM). Postoperative complications occurred in 4 patients, including urinary retention in 1 patient, pulmonary infection in 1 patient, intestinal adhesion in 1 patient and peristomal dermatitis in 1 patient, and were graded as ClavienDindo grade 3 or lower and cured. No distant metastasis or local recurrence was found for any of the patients in the postoperative follow-up.

CONCLUSIONS

The application of the LSRA exposure method might be helpful for perineal exposure during APR for rectal cancer, which could improve intraoperative safety and surgical efficiency, achieve one-person operation, and increase the comfort of operators.