Revisiting the genital and femoral branches of the genitofemoral nerve: Suggestion for a more accurate terminology

Variations of the extrapsoas course of the lumbar plexus with implications for the lateral transpsoas approach to the lumbar spine: a cadaveric study

BACKGROUND

Together with an increased interest in minimally invasive lateral transpsoas approach to the lumbar spine goes a demand for detailed anatomical descriptions of the lumbar plexus. Although definitions of safe zones and essential descriptions of topographical anatomy have been presented in several studies, the existing literature expects standard appearance of the neural structures. Therefore, the aim of this study was to investigate the variability of the extrapsoas portion of the lumbar plexus in regard to the lateral transpsoas approach.

METHODS

A total of 260 lumbar regions from embalmed cadavers were utilized in this study. The specimens were dissected as per protocol and all nerves from the lumbar plexus were morphologically evaluated.

RESULTS

The most common variation of the iliohypogastric and ilioinguinal nerves was fusion of these two nerves (9.6%). Nearly in the half of the cases (48.1%) the genitofemoral nerve left the psoas major muscle already divided into the femoral and genital branches. The lateral femoral cutaneous nerve was the least variable one as it resembled its normal morphology in 95.0% of cases. Regarding the variant origins of the femoral nerve, there was a low formation outside the psoas major muscle in 3.8% of cases. The obturator nerve was not variable at its emergence point but frequently branched (40.4%) before entering the obturator canal. In addition to the proper femoral and obturator nerves, accessory nerves were present in 12.3% and 9.2% of cases, respectively.

CONCLUSION

Nerves of the lumbar plexus frequently show atypical anatomy outside the psoas major muscle. The presented study provides a compendious information source of the possibly encountered neural variations during retroperitoneal access to different segments of the lumbar spine.

Genitofemoral Nerve Variation: An Attempt to Explain the Embryological Basis via a Case Report

The genitofemoral nerve (GFN) presents with a variable course in nearly half of the population. This variation can be seen in its availability, course, and branching. Here, a notable case during a cadaveric dissection revealed an unusually high bifurcation of the GFN on the left side, contrasting with the typical bifurcation observed on the right. This divergence was highlighted using colored markers to aid educational visualization, facilitating a comprehensive learning experience about the nerve's variability and its functional implications, such as the cremasteric reflex. Embryologically, these variations stem from the migratory paths of myotomes during development, influenced by extrinsic signals and growth factors. Despite the high incidence of anatomical variability, the muscular structure remains consistent, suggesting that the nerve's formation is more susceptible to developmental shifts than the muscles it innervates. Clinically, understanding GFN variations is crucial due to the nerve's involvement in conditions like genitofemoral neuropathy, which can arise from surgical procedures. Accurate knowledge of these variations aids in precise diagnostic and therapeutic interventions, reducing complications, and enhancing patient outcomes in lower abdominal and groin surgeries. However, further research is needed to elucidate the exact embryological and genetic underpinnings of these variations.

Anatomy and terminology of groin pain: Current concepts

Groin pain is a common symptom in athletes. The complex anatomy of the area and the various terms used to describe the etiology behind groin pain have led to a confusing nomenclature. To solve this problem, three consensus statements have been already published in the literature: the Manchester Position Statement in 2014, the Doha agreement in 2015, and the Italian Consensus in 2016. However, when revisiting recent literature, it is evident that the use of non-anatomic terms remains common, and the diagnoses sports hernia, sportsman's hernia, sportsman's groin, Gilmore's groin, athletic pubalgia, and core muscle injury are still used by many authors. Why are they still in use although rejected? Are they considered synonyms, or they are used to describe different pathology? This current concepts review article aims to clarify the confusing terminology by examining to which anatomical structures authors refer when using each term, revisit the complex anatomy of the area, including the adductors, the flat and vertical abdominal muscles, the inguinal canal, and the adjacent nerve branches, and propose an anatomical approach, which will provide the basis for improved communication between healthcare professionals and evidence-based treatment decisions.

Sensibility, Sensation, and Nerve Regeneration after Reconstructive Genital Surgery: Evolving Concepts in Neurobiology

BACKGROUND

Sensory recovery following phalloplasty and vaginoplasty for gender dysphoria is essential to the overall success of gender-confirming surgery. Anecdotal evidence suggests that superior reinnervation results are seen in genitoplasty compared to other peripheral nerve repair scenarios. Despite these observed differences, the quality of available literature is poor.

METHODS

The authors reviewed the body of English language literature regarding sensory outcomes following genitoplasty for gender confirmation.

RESULTS

The available body of literature discussing the basic science and clinical science aspects of sensory recovery following gender-confirming genitoplasty is small. Available data show that sensory recovery following vaginoplasty produces high rates of reported orgasmic ability, largely through the neoclitoris, and a neovagina with vibratory and pressure sensation similar to that of the native vagina. Phalloplasty sensory outcomes are variable, with the largest series reporting return of sensation in the neophallus that is slightly less than what is measured in control men. Erogenous sensation, including the ability to orgasm, is present in nearly all patients after several months.

CONCLUSIONS

Existing series indicate that genitoplasty patients experience faster and more complete recovery than any other peripheral nerve regeneration scenarios. However, there are many potential confounding factors in assessment and reporting, and more consistent and reproducible measure endpoints measures are needed. Further research is needed to better understand both the basic science and clinical science of peripheral nerve regeneration in genitoplasty, which may change fundamental aspects of current paradigms of peripheral nerve regeneration.

Review: Pelvic nerves - from anatomy and physiology to clinical applications

A prerequisite for nerve-sparing pelvic surgery is a thorough understanding of the topographic anatomy of the fine and intricate pelvic nerve networks, and their connections to the central nervous system. Insights into the functions of pelvic nerves will help to interpret disease symptoms correctly and improve treatment. In this article, we review the anatomy and physiology of autonomic pelvic nerves, including their topography and putative functions. The aim is to achieve a better understanding of the mechanisms of pelvic pain and functional disorders, as well as improve their diagnosis and treatment. The information will also serve as a basis for counseling patients with chronic illnesses. A profound understanding of pelvic neuroanatomy will permit complex surgery in the pelvis without relevant nerve injury.

Lateral Lumbar Interbody Fusion: Review of Surgical Technique and Postoperative Multimodality Imaging Findings

The lateral lumbar interbody fusion (LLIF) approach is a minimally invasive surgery that can be used as an alternative to traditional lumbar interbody fusion techniques. LLIF accesses the intervertebral disk through the retroperitoneum and psoas muscle to avoid major vessels and visceral organs. The exposure of retroperitoneal structures during LLIF leads to unique complications compared with other surgical approaches. An understanding of the surgical technique and its associated potential complications is necessary for radiologists who interpret imaging before and after LLIF. Preoperative imaging must carefully assess the location of anatomic structures, including major retroperitoneal vasculature, lumbar nerve roots, lumbosacral plexus, and the genitofemoral nerve, relative to the psoas muscle. Multiple imaging modalities can be used in postoperative assessment including radiographs, CT, CT myelography, and MRI. Of these, CT is the preferred modality, because it can assess a range of complications relating to both the retroperitoneal exposure and the spinal instrumentation, as well as bone integrity and fusion status. This article describes surgical approaches for lumbar interbody fusion, comparing the approaches' indications, contraindications, advantages, and disadvantages; reviews the surgical technique of LLIF and relevant anatomic considerations; and illustrates for interpreting radiologists the normal postoperative findings and potential postsurgical complications of LLIF.

A study to improve identification of the retroperitoneal course of iliohypogastric, ilioinguinal, femorocutaneous and genitofemoral nerves during laparoscopic triple neurectomy

BACKGROUND

Laparoscopic triple neurectomy is an available treatment option for chronic groin pain, but a poor working knowledge of the retroperitoneal neuroanatomy makes it an unsafe technique.

OBJECT

Describe the retroperitoneal course of iliohypogastric, ilioinguinal, lateral femoral cutaneous and genitofemoral nerves, to guide the surgeon who operates in this region.

METHODS

Fifty adult cadavers were dissected resulting in 100 anatomic specimens. Additionally, 30 patients were operated for refractory chronic inguinal pain, using laparoscopic triple neurectomy. All operations and dissections were photographed. Measurements were made between the nerves of the lumbar plexus and various landmarks: interneural distances in a vertical midline plane, posterior or anterior iliac spine and branch presentation model.

RESULTS

The ilioinguinal and iliohypogastric nerves were independent in 78% (Type II) and separated by an average of 2.5 ± 0.8 cm. In surgery study, only 38% were recognized as Type II and at a significantly greater distance (3.5 ± 1.2 cm, p < 0.001). The distance between ilioinguinal and lateral femoral cutaneous nerves was also greater during surgery, with statistical significance (5.1 ± 1.5 versus 4.2 ± 1.5, p < 0.005). The distance of the nerves to their bone references were not statistically different. The genitofemoral nerve emerged from the psoas major muscle in 20% as two separate branches (Type II), regardless of the study. The lateral femoral cutaneous nerve had a mean distance of 0.98 ± 1.6 cm medial to the anterior superior iliac spine.

CONCLUSION

The identification of the IH, II, FC and GF nerves is essential to reduce the rate of failures in the treatment of CGP. The frequent anatomical variations of the lumbar plexus nerves make knowledge of their courses in the retroperitoneal space essential to ensure safe surgery. The location of the nerves in the LTN is distorted by up to 1 cm. regarding references in the cadavers.