Ilioinguinal Neuropathy

Pulsed Radiofrequency in the Management of Postsurgical Abdominal Wall Chronic Pain: A Report From a Single Oncological Center

Chronic postsurgical pain (CPSP) is defined as pain that develops or increases in intensity after a surgical procedure or tissue injury and persists beyond the healing process, lasting at least three months after the precipitating event. Often neuropathic in nature, CPSP can be challenging to manage. CPSP is a common complication, with data suggesting an incidence ranging from 5% to 85%, depending on the type of procedure. Meralgia paresthetica (MP) and ilioinguinal/iliohypogastric neuralgias (IH/IL N) are two possible clinical scenarios of CPSP following lower abdominal procedures. Pulsed radiofrequency (PRF) is a minimally invasive technique of peripheral neuromodulation effective in various pain etiologies; however, evidence is scarce regarding its use in MP and IH/IL N. This case series aims to assess the potential role of PRF in the management of CPSP following abdominal wall procedures. This case series was set in a single oncological center between January 2017 and February 2022 and included adult patients (>18 years old) referred to our unit with a high suspicion of postsurgical MP or IH/IL N refractory to conservative treatment. PRF was performed after a positive diagnostic block in patients whose pain could not be controlled despite optimal medical treatment. The efficacy of PRF was assessed regarding pain intensity using the verbal numeric scale (VNS) and the duration of pain relief in weeks. The follow-up period was from the initial PRF procedure to the end of data collection. Parametric data were presented as mean and standard deviation (SD), and non-parametric data as median (minimum-maximum). Seventeen patients were included: 82.35% (n=14) were female, and the mean age was 58.0 ± 11.35 years. MP was present in 47.1% (n=8) and IH/IL N in 52.9% (n=9). Transverse rectus abdominis muscle flap reconstruction (TRAM) was the most common procedure (n=5, 29.41%). Diagnostic blocks were performed in 88.24% (n=15) of the patients. Initial VNS scores were 7.59 ± 2.62; 2.82 ± 2.62 at 24 hours; and 2.47 ± 1.58 at 15 days. During follow-up, 70.59% (n=12) of patients had no recurrence of initial symptoms. A second PRF was performed in 29.41% (n=5) cases based on the recurrence of symptoms, following a mean period of pain relief of 112 (8-238) weeks. No major or minor complications were identified during early or late follow-up. PRF can be a useful tool to improve the multimodal management of postsurgical abdominal wall chronic pain.

[Rare nerve compression neuropathies]

UNCOMMON NERVE COMPRESSION SYNDROMES

In regard to the complex anatomical relationship of peripheral nerves and muscles, tendons, fasciae as well as their long course within those anatomical structures and additional close contact to bony structures, they are prone to suffer from local compression syndromes. Hence creating a vast majority of entrapment syndromes - well described in literature for almost every single nerve. The purpose of this article is to give an overview of symptoms, signs, diagnostic studies and treatment options, addressing especially the less known syndromes. Compression syndromes of the upper arm and shoulder region include the suprascapular nerve syndrome the compression of the axillary nerve within the spatium quadrilaterale and the compression of the long thoracic nerve at the chest wall. The upper extremity offers a variety of infrequent entrapment syndromes, as the pronator teres syndrome and anterior interosseus syndrome, both resulting from pressure to the median nerve in the forearm. Compression neuropathy in the course of the radial nerve in the distal upper extremity is also known as supinator syndrome. Guyon's canal syndrome is the ulnar side equivalent to the well-known carpal tunnel syndrome. In the case of a Cheiralgia paresthetica, a compression of a sensory branch of the superficial radial nerve can be seen. In the lower extremities, a variety of nerves especially in the groin and thigh area can be compressed as they pass through the narrow spaces between the abdominal muscles or underneath the inguinal ligament. Compression of the lateral femoral cutaneous nerve is the most common syndrome. Compression syndromes of the femoral and obturator nerves are most often iatrogenic. Pain around the knee, especially the lateral part and following orthopedic procedures of the knee, can arise from a compression or a lesion of a small infrapatellar branch of the saphenous nerve. Another probably underdiagnosed syndrome is piriformis syndrome, resulting from an entrapment of the sciatic nerve as it passes through certain muscular structures. In the distal lower extremity, the peroneal and tibial nerves can be compressed at multple sites, clinically known as peroneal nerve paralysis resulting from nerve compression around the fibular head, the anterior and posterior tarsal tunnel syndrome, and Morton's metatarsalgia.

Is There Enough Knowledge to Standardize a Cannabis sativa L. Medicinal Oil Preparation with a High Content of Cannabinoids?

Introduction: Cannabis sativa L. medicinal oils are good therapeutic options due to their wide spectrum of pharmacological applications and the easy adjustment of individual doses. The lack of standardization of methodology in the preparation of medicinal oil using the Cannabis crude extract results in elevated variability of cannabinoid concentration in the final product. The elevated variability impairs the understanding of beneficial and adverse effects related to dose-response pharmacological activities. Objective: This study aimed to conduct a review on the current methods of Cannabis oil preparation present in the literature, to demonstrate the most appropriate methodologies to ensure a product with high content of cannabinoids and terpenes. Results: The decarboxylation stage is essential for the conversion of acid cannabinoids into neutral cannabinoids, which are substances with the highest bioavailability. Lower temperatures for longer periods of time instead of high temperatures in less time are highly recommended to ensure that all the acidic cannabinoids have passed through decarboxylation. For the guarantee of a high terpene content, the separate addition of essential oil to the fixed oil prepared from the crude extract should be considered. Ultrasound-assisted extraction is one of the best performing methodologies because it is cheaper than other techniques, such as supercritical fluid extraction, besides that, ultrasound extraction is effective in short extraction times and uses small amounts of solvent when compared with other techniques. Conclusion: Although the literature about the methods of preparation of Cannabis medicinal oil is scarce, it is possible to standardize an optimized, low-cost, and effective Cannabis extractive methodology from the results found in the literature; however, this will depend on new research for methodological validation.

Ultrasound-guided injections in pelvic entrapment neuropathies

Pelvic entrapment neuropathies represent a group of chronic pain syndromes that significantly impede the quality of life. Peripheral nerve entrapment occurs at specific anatomic locations. There are several causes of pelvic entrapment neuropathies, such as intrinsic nerve abnormality or inflammation with scarring of surrounding tissues, and surgical interventions in the abdomen, pelvis and the lower limbs. Entrapment neuropathies in the pelvic region are not widely recognized, and still tend to be underdiagnosed due to numerous differential diagnoses with overlapping symptoms. However, it is important that entrapment neuropathies are correctly diagnosed, as they can be successfully treated. The lateral femoral cutaneous nerve, ischiadic nerve, genitofemoral nerve, pudendal nerve, ilioinguinal nerve and obturator nerve are the nerves most frequently causing entrapment neuropathies in the pelvic region. Understanding the anatomy as well as nerve motor and sensory functions is essential in recognizing and locating nerve entrapment. The cornerstone of the diagnostic work-up is careful physical examination. Different imaging modalities play an important role in the diagnostic process. Ultrasound is a key modality in the diagnostic work-up of pelvic entraptment neuropathies, and its use has become increasingly widespread in therapeutic procedures. In the article, the authors describe the background of pelvic entrapment neuropathies with special focus on ultrasound-guided injections.

Ilioinguinal Nerve Neurectomy is better than Preservation in Lichtenstein Hernia Repair: A Systematic Literature Review and Meta-analysis

OBJECTIVE

This study aimed to evaluate the incidence of chronic groin pain (primary outcome) and alterations of sensitivity (secondary outcome) after Lichtenstein inguinal hernia repair, comparing neurectomy with ilioinguinal nerve preservation surgery. The exact cause of chronic groin postoperative pain after mesh inguinal hernia repair is usually unclear. Section of the ilioinguinal nerve (neurectomy) may reduce postoperative chronic pain.

METHODS

We followed PRISMA guidelines to identify randomized studies reporting comparative outcomes of neurectomy versus ilioinguinal nerve preservation surgery during Lichtenstein hernia repairs. Studies were identified by searching in PubMed, Scopus, and Web of Science from April 2020. The protocol for this systematic review and meta-analysis was submitted and accepted from PROSPERO: CRD420201610.

RESULTS

In this systematic review and meta-analysis, 16 RCTs were included and 1550 patients were evaluated: 756 patients underwent neurectomy (neurectomy group) vs 794 patients underwent ilioinguinal nerve preservation surgery (nerve preservation group). All included studies analyzed Lichtenstein hernia repair. The majority of the new studies and data comes from a relatively narrow geographic region; other bias of this meta-analysis is the suitability of pooling data for many of these studies. A statistically significant percentage of patients with prosthetic inguinal hernia repair had reduced groin pain at 6 months after surgery at 8.94% (38/425) in the neurectomy group versus 25.11% (113/450) in the nerve preservation group [relative risk (RR) 0.39, 95% confidence interval (CI) 0.28-0.54; Z = 5.60 (P < 0.00001)]. Neurectomy did not significantly increase the groin paresthesia 6 months after surgery at 8.5% (30/353) in the neurectomy group versus 4.5% (17/373) in the nerve preservation group [RR 1.62, 95% CI 0.94-2.80; Z = 1.74 (P = 0.08)]. At 12 months after surgery, there is no advantage of neurectomy over chronic groin pain; no significant differences were found in the 12-month postoperative groin pain rate at 9% (9/100) in the neurectomy group versus 17.85% (20/112) in the inguinal nerve preservation group [RR 0.50, 95% CI 0.24-1.05; Z = 1.83 (P = 0.07)]. One study (115 patients) reported data about paresthesia at 12 months after surgery (7.27%, 4/55 in neurectomy group vs. 5%, 3/60 in nerve preservation group) and results were not significantly different between the two groups [RR 1.45, 95% CI 0.34, 6.21;Z = 0.51 (P = 0.61)]. The subgroup analysis of the studies that identified the IIN showed a significant reduction of the 6th month evaluation of pain in both groups and confirmed the same trend in favor of neurectomy reported in the previous overall analysis: statistically significant reduction of pain 6 months after surgery at 3.79% (6/158) in the neurectomy group versus 14.6% (26/178) in the nerve preservation group [RR 0.28, 95% CI 0.13-0.63; Z = 3.10 (P = 0.002)].

CONCLUSION

Ilioinguinal nerve identification in Lichtenstein inguinal hernia repair is the fundamental step to reduce or avoid postoperative pain. Prophylactic ilioinguinal nerve neurectomy seems to offer some advantages concerning pain in the first 6th month postoperative period, although it might be possible that the small number of cases contributed to the insignificancy regarding paresthesia and hypoesthesia. Nowadays, prudent surgeons should discuss with patients and their families the uncertain benefits and the potential risks of neurectomy before performing the hernioplasty.