Anatomical variations of the axilla

Anatomical variants of the intercostobrachial nerve and its preservation during surgery, a systematic review and meta-analysis

BACKGROUND

The anatomic variants of the intercostobrachial nerve (ICBN) represent a potential risk of injuries during surgical procedure such as axillary lymph node dissection and sentinel lymph node biopsy in breast cancer and melanoma patients. The aim of this systematic review and meta-analysis was to investigate the different origins and branching patterns of the intercostobrachial nerve also providing an analysis of the prevalence, through the analysis of the literature available up to September 2023.

MATERIALS AND METHODS

The protocol for this study was registered on PROSPERO (ID: CRD42023447932), an international prospective database for reviews. The PRISMA guideline was respected throughout the meta-analysis. A systematic literature search was performed using PubMed, Scopus and Web of Science. A search was performed in grey literature through google.

RESULTS

We included a total of 23 articles (1,883 patients). The prevalence of the ICBN in the axillae was 98.94%. No significant differences in prevalence were observed during the analysis of geographic subgroups or by study type (cadaveric dissections and in intraoperative dissections). Only five studies of the 23 studies reported prevalence of less than 100%. Overall, the PPE was 99.2% with 95% Cis of 98.5% and 99.7%. As expected from the near constant variance estimates, the heterogeneity was low, I2 = 44.3% (95% CI 8.9%-65.9%), Q = 39.48, p = .012. When disaggregated by evaluation type, the difference in PPEs between evaluation types was negligible. For cadaveric dissection, the PPE was 99.7% (95% CI 99.1%-100.0%) compared to 99.0% (95% CI 98.1%-99.7%).

CONCLUSIONS

The prevalence of ICBN variants was very high. The dissection of the ICBN during axillary lymph-node harvesting, increases the risk of sensory disturbance. The preservation of the ICBN does not modify the oncological radicality in axillary dissection for patients with cutaneous metastatic melanoma or breast cancer. Therefore, we recommend to operate on these patients in high volume center to reduce post-procedural pain and paresthesia associated with a lack of ICBN variants recognition.

Axillary Lymphadenectomy: Safe Dissection Through a Correct Technique

The primary treatment of breast cancer in sentinel-positive ganglia includes axillary lymphatic nodal dissection. The LAD (lymphatic axillary dissection) has decreased in overall numbers but due to the increasing incidence of breast cancer, it is practised on a daily basis, even though there is a myriad of complications such as numbness of the upper limb and chest wall, movement restriction of the upper limb, and chronic pain which appear due to trauma to the nerves which pass through the axilla. However, the utility in the overall survival or DFS (disease-free survival) of the patient is unquestionable.  In our study, through the dissection of cadavers, we exposed the vital structures and the anatomical relations of this region. We aimed to offer a map or technique for the surgeon to follow to decrease the overall morbidity of this procedure.

From Cadaveric Dissection to the Operating Room: A Unilateral Double Intercostobrachial Nerve and the Implications in Axillary Lymph Node Dissection

There are multiple treatment options for breast cancer (BC), including lumpectomy, chemo- and radiotherapy, complete mastectomy, and, when indicated, an axillary lymph node dissection. Such node dissections commonly lead the surgeon to encounter the intercostobrachial nerve (ICBN), which, if injured, leads to significant postoperative numbness of the upper arm. To assist in identifying the ICBN, we report a unilateral variation of a dual ICBN. The first ICBN (ICBN I) originates from the second intercostal space, as classically described in human anatomy. On the contrary, the second ICBN (ICBN II) originates from the second and third intercostal spaces. The anatomical knowledge of ICBN origin and its variations are crucial for axillary lymph node dissection in BC and other surgical interventions that involve the axillary region (e.g., regional nerve blocks). An iatrogenic injury of the ICBN has been associated with postoperative pain, paresthesia, and loss of upper extremity sensation in the dermatome supplied by this nerve. Therefore, maintaining the integrity of the ICBN is a worthy goal during axillary dissections in BC patients. Increasing the awareness of ICBN variants among surgeons reduces potential injuries, which would contribute to the BC patient's quality of life.

Intercostobrachial neuralgia—a case of bizzare diagnosis?

Background

Intercostobrachial neuralgia is a rare and bizarre diagnosis usually missed by many clinicians. The rare occurrence and absence of clear diagnostic criteria could be a result of this missed diagnosis. The symptoms could range from debilitating pain in the axilla, medial arm, and forearm at rest and with specific shoulder movements. The symptoms are very distinct from axillary web syndrome in which the patient could have thickening of subcutaneous tissue of axilla with affected shoulder mobility but absence of neural symptoms. The diagnostic and treatment procedure involving breast cancer may cause injury or lesion of the intercostobrachial nerve and is of particular interest to the surgeons, pain physicians, and physical therapists. The diagnosis is reached after excluding all the other possible diagnoses. The treatment of this post-surgical intercostobrachial neuralgia can range from cryoneurolysis, ultrasound-guided nerve block, steroid injection, and paravertebral nerve block. Lidocaine injection and avoiding certain positions like flexion and abduction are helpful in certain patients. Unfortunately, there is not much literature available on possible manual therapy treatments of this diagnosis. Therefore, this case report focuses on potential manual therapies to address this intricate diagnosis.

Case presentation

The patient is a 38-year-old Asian female reported to an outpatient orthopedic physical therapy clinic with left medial arm and forearm pain for the past 5 years. Medical history included left breast lump removal surgery 9 years ago and cervical laminectomy C6–C7 with little success. The quick disability arm and hand scale showed a 36% disability score of function. The manual therapy approach targeted the cervicothoracic junction, second and third costovertebral joint, thoracic spine (T1–T8), and atlantooccipital joint (C0–C1). The patient showed significant improvement in function with a DASH score falling to 0% disability with a hands-on approach.

Conclusion

The intercostobrachial neuralgia is usually undiagnosed by various practitioners, physicians, and surgeons. The clinicians must consider manual treatments to the second and third rib and soft tissue mobilizations around the axillary region. The patient demonstrated significant improvement in symptoms with this approach.

Cadaveric study identifying clinical sonoanatomy for proximal and distal approaches of ultrasound-guided intercostobrachial nerve block

Background and objectives

The intercostobrachial nerve (ICBN) has significant anatomical variation. Localization of the ICBN requires an operator’s skill. This cadaveric study aims to describe two simple ultrasound-guided plane blocks of the ICBN when it emerges at the chest wall (proximal approach) and passes through the axillary fossa (distal approach).

Methods

The anatomical relation of the ICBN and adjacent structures was investigated in six fresh cadavers. Thereafter, we described two potential techniques of the ICBN block. The proximal approach was an injection medial to the medial border of the serratus anterior muscle at the inferior border of the second rib. The distal approach was an injection on the surface of the latissimus dorsi muscle at 3–4 cm caudal to the axillary artery. The ultrasound-guided proximal and distal ICBN blocks were performed in seven hemithoraxes and axillary fossae. We recorded dye staining on the ICBN, its branches and clinically correlated structures.

Results

All ICBNs originated from the second intercostal nerve and 34.6% received a contribution from the first or third intercostal nerve. All ICBNs gave off axillary branches in the axillary fossa and ran towards the posteromedial aspect of the arm. Following the proximal ICBN block, dye stained on 90% of all ICBN’s origins. After the distal ICBN block, all terminal branches and 43% of the axillary branches of the ICBN were stained.

Conclusions

The proximal and distal ICBN blocks, using easily recognized sonoanatomical landmarks, provided consistent dye spread to the ICBN. We encourage further validation of these two techniques in clinical studies.

The effectiveness of additional thoracic paravertebral block in improving the anesthetic effects of regional anesthesia for proximal humeral fracture surgery in elderly patients: study protocol for a randomized controlled trial

BACKGROUND

The innervation of the shoulder-upper-extremity area is complicated and unclear. Regional anesthesia with a brachial plexus and cervical plexus block is probably inadequate for the proximal humeral surgery. Missing blockade of the T1-T2 nerves may be the reason. We conduct this prospective randomized controlled trial (RCT) to explore whether an additional T2 thoracic paravertebral block (TPVB) can improve the success rate of regional anesthesia for elderly patients in proximal humeral fracture surgery.

METHODS/DESIGN

The patients aged 65 years or older, referred for anterior-approach proximal humeral fracture surgery, will be enrolled. Each patient will be randomly assigned 1:1 to receive a combined interscalene brachial plexus with superficial cervical plexus block (IC) (combined interscalene brachial plexus with superficial cervical plexus block) or an IC block combined with thoracic paravertebral block (ICTP) block (combined thoracic paravertebral block with brachial plexus and superficial cervical plexus block). The primary outcome is the success rate of regional anesthesia without rescue analgesic methods. The secondary outcomes are as follows: sensory block at the surgical area, proportion of patients who need rescue anesthesia (intravenously administered remifentanil or conversion to general anesthesia), cumulative doses of intraoperative vasoactive medications and adverse events. The total sample size is estimated to be 80 patients.

DISCUSSION

This RCT aims to confirm whether an additional T2 TPVB can provide better anesthetic effects of regional anesthesia with brachial and cervical plexus block in elderly patients undergoing proximal humeral surgery.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03919422. Registered on 19 April 2019.

AAAPT Diagnostic Criteria for Acute Pain Following Breast Surgery

Acute pain after breast surgery decreases the quality of life of cancer survivors. Previous studies using a variety of definitions and methods report prevalence rates between 10% and 80%, which suggests the need for a comprehensive framework that can be used to guide assessment of acute pain and pain-related outcomes after breast surgery. A multidisciplinary task force with clinical and research expertise performed a focused review and synthesis and applied the 5 dimensional framework of the AAAPT (Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks [ACTTION], American Academy of Pain Medicine [AAPM], American Pain Society [APS] Pain Taxonomy) to acute pain after breast surgery. Application of the AAAPT taxonomy yielded the following: 1) Core Criteria: Location, timing, severity, and impact of breast surgery pain were defined; 2) Common Features: Character and expected trajectories were established in relevant surgical subgroups, and common pain assessment tools for acute breast surgery pain identified; 3) Modulating Factors: Biological, psychological, and social factors that modulate interindividual variability were delineated; 4) Impact/Functional Consequences: Domains of impact were outlined and defined; 5) Neurobiologic Mechanisms: Putative mechanisms were specified ranging from nerve injury, inflammation, peripheral and central sensitization, to affective and social processing of pain. PERSPECTIVE: The AAAPT provides a framework to define and guide improved assessment of acute pain after breast surgery, which will enhance generalizability of results across studies and facilitate meta-analyses and studies of interindividual variation, and underlying mechanism. It will allow researchers and clinicians to better compare between treatments, across institutions, and with other types of acute pain.

Anatomical variations of the subscapular pedicle and its terminal branches: an anatomical study and a reappraisal in the light of current surgical approaches

PURPOSE

While anatomical variations of the subscapular vessels are frequently encountered during axillary dissection, little is found in the literature. The aim of this cadaveric study was to define arterial and venous anatomical variations and frequencies of the subscapular vascular pedicle and its terminal/afferent vessels in women.

METHODS

We performed 80 dissections of the axillary region on forty female formalin-embalmed cadavers. Each anatomical arrangement was photographed and recorded on a scheme before analysis.

RESULTS

We propose a new classification of the subscapular pedicle variations. We observed three types of subscapular arterial variation. The type Ia was the most frequent arrangement (71% of our dissections), the type Ib was observed in 11% and the type II in 18% of cases. We observed four types of subscapular venous variation. The type Ia was observed in 63% of cases, the type Ib in 14%, the type II in 14% and the type III in 10% of cases.

CONCLUSIONS

This knowledge of the anatomical variation arrangement and frequencies of the subscapular vascular pedicle will assist the surgeon when dissecting the axillary region for malignant or reconstructive procedures.

Single institution analysis of incidence and risk factors for post-mastectomy pain syndrome

Post Mastectomy Pain Syndrome (PMPS) is a common postoperative condition for breast cancer, but has been ignored. The aim of this study was to investigate the prevalence of PMPS and the risk factors in women submitted to surgical treatment for breast cancer. The study included 532 postoperative breast cancer patients in a hospital for five consecutive years period, of whom 473 were considered eligible and included in the study. A total of 420 people completed a questionnaire survey, which revealed that 152 (36.2%) had ever suffered from PMPS and 18 (11.8%) sought treatment. Of the patients with PMPS, 34 (22.4%) had a history of chronic pain. Patients with PMPS were younger than patients without PMPS (50.5 ± 10.4 vs 53.5 ± 11.1). Univariate analysis showed that age, history of chronic pain, tumor staging, number of lymphadenectomy were significantly different between the two groups. Multivariate analysis shows that age and history of chronic pain were independent risk factors. The incidence of PMPS in postoperative breast cancer patients can reach 36.2%, and age as well as previous history of pain are independent risk factors for PMPS. The combination of prevention and treatment may be an effective way to reduce PMPS.

An improved technical trick for identification of the thoracodorsal nerve during axillary clearance surgery: a cadaveric dissection study

Background

Accurate anatomical landmarks to locate the thoracodorsal nerve are important in axillary clearance surgery.

Methods

Twenty axillary dissections were carried out on ten preserved Sri Lankan cadavers. Cadavers were positioned dorsal decubitus with upper limbs abducted to 90⁰. An incision was made in the upper part of the anterior axillary line. The lateral thoracic vein was identified and traced bi-directionally. The anatomical location of the thoracodorsal nerve was studied in relation to the lateral border of pectoralis minor and from a point along the lateral thoracic vein, 2 cm inferior to its confluence with the axillary vein.

Results

The lateral thoracic vein was invariably present in all the specimens. All the lateral thoracic veins passed lateral to the lateral border of pectoralis minor except in one specimen, where the lateral thoracic vein passed along its lateral border. The thoracodorsal nerve was consistently present posterolateral to the lateral thoracic vein. The mean distance to the lateral thoracic vein from the lateral border of pectoralis minor was 28.7 ± 12.6 mm. The mean horizontal distance, depth, and displacement, from a point along the lateral thoracic vein, 2 cm inferior to its confluence with the axillary vein to the thoracodorsal nerve were 14.5 ± 8.9 mm, 19.7 ± 7.3 mm and 25 ± 5 mm respectively. The thoracodorsal nerve was found in a posterolateral direction, at a 54⁰ ± 12⁰ angle to the horizontal plane, 95% of the time.

Conclusions

The lateral thoracic vein is an accurate guide to the thoracodorsal nerve. We recommend exploring for the thoracodorsal nerve from a point 2 cm from the confluence of the lateral thoracic vein and the axillary vein for a distance of 25 ± 5 mm in a posterolateral direction, at a 54⁰ ± 12⁰ angle to the horizontal plane.

Origin, Branching, and Communications of the Intercostobrachial Nerve: a Meta-Analysis with Implications for Mastectomy and Axillary Lymph Node Dissection in Breast Cancer

The intercostobrachial nerve (ICBN), which usually originates from the lateral cutaneous branch of the second intercostal nerve, innervates areas of the axilla, lateral chest, and medial arm. It is at risk for injury during operative procedures that are often used in the management of breast cancer and such injury has been associated with postoperative sensory loss and neuropathic pain, decreasing the quality of life. PubMed, Excerpta Medica Database (EMBASE), ScienceDirect, Google Scholar, China National Knowledge Infrastructure (CNKI), Scientific Electronic Library Online (SciELO), Biosciences Information Service (BIOSIS), and Web of Science were searched comprehensively. Data concerning the prevalence, branching, origin and communications of the ICBN were extracted and pooled into a meta-analysis. A total of 16 studies (1,567 axillas) reported data indicating that the ICBN was present in 98.4% of person. It most often (90.6%) originated from fibers at the T2 spinal level and commonly coursed in two branching patterns: as a single trunk in 47.0% of cases and as a bifurcating pattern in 42.2%. In the latter cases, the bifurcation was usually unequal (63.4%). Additionally, the ICBN presented with anastomosing communication to the brachial plexus in 41.3% of cases. The ICBN is a prevalent and variable structure at significant risk for injury during operative procedures of the axilla. In view of the postoperative pain and paresthesia experienced by patients following injury, surgeons need to exercise caution and aim to preserve the ICBN when possible. Ultimately, careful dissection and knowledge of ICBN anatomy could allow postoperative complications to be reduced and patient's quality of life increased.

Venous anomalies of the axilla: a single-institution experience

AIM

Surgical treatment is still the cornerstone in the treatment of breast cancer, a very common neoplasia, particularly affecting the female elderly population. Axillary dissection is crucial in the treatment of some tumours, but variations in axillary vessels anatomy are poorly described in standard anatomy and surgical textbook. We aimed to describe anatomical variations in axillary vessels found in our institutional experience.

PATIENTS AND METHODS

A prospective 3-year study was conducted in our institution from January 2012 to December 2014. Sixty-one consecutive axillary lymph node dissections (ALNDs) were performed in 61 patients who underwent surgery for stage II and III invasive breast cancer. Anatomical details of axillary vascular anatomy and its variations have been evaluated, described and stored in a prospective database.

RESULTS

Sixty-one ALNDs have been performed in the study period. The anatomy of lateral thoracic vein, angular vein and axillary vein was studied and compared with standard anatomical description. Eighteen percentage of venous variations were found out of the 61 dissection performed.

CONCLUSIONS

Vascular anatomy of axilla is complex and variable. A better knowledge of all possible variations might be helpful in preventing injuries during ALND.

Ultrasound imaging accurately identifies the intercostobrachial nerve

Objectives:

To test the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN) can be achieved under ultrasound (US) guidance using a small volume of local anesthetic.

Methods:

Twenty-eight adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using one ml of 2% lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head.

Results:

The ICBN appears as a hyper-echoic structure. The nerve diameter was 2.3±0.28 mm, and the depth was 9±0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3±1.6 cm anteriorly; 6.2±2.9 cm posteriorly; 9.4±2.9 cm proximally; and 9.2±4.4 cm distally. Intercostobrachial nerve blockade using one ml of local anesthetic was successful in all cases.

Conclusion:

The present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade.

Lymph nodes behind the axillary neurovascular bundle: case report and cadaveric study of frequency and distribution

Axillary clearance was undertaken in a 58-year-old male with massive lymph node enlargement caused by melanoma from an unknown primary site. We discovered a group of metastatic lymph nodes behind the axillary neurovascular bundle. This group of nodes (retro-axillary lymph nodes) could represent an extension of the subscapular group, or the seventh group of axillary lymphoid nodes. They were successfully removed using an ad hoc surgical technique, and the subsequent findings are presented herein. To check the frequency of these lymph nodes in this area, we conducted a study on 15 cadavers (30 armpits). The technique of cadaveric sampling is described. Retro-axillary tissue was histologically processed to determine the number of lymph nodes present. It was found that lymph nodes were present in the defined area in 18 of the 30 (60 %) armpits explored. We recommend assessment of the retro-axillary space during surgery entailing massive axillary lymph node involvement.