Periorbital and Temporal Anatomy, "Targeted Fat Grafting," and How a Novel Circulatory System in Human Peripheral Nerves and Brain May Help Avoid Nerve Injury and Blindness During Routine Facial Augmentation

Cerebrospinal Fluid Flow Extends to Peripheral Nerves

Cerebrospinal fluid (CSF) is an aqueous solution responsible for nutrient delivery and waste removal for the central nervous system (CNS). The three-layer meningeal coverings of the CNS support CSF flow. Peripheral nerves have an analogous three-layer covering consisting of the epineurium, perineurium, and endoneurium. Peripheral axons, located in the inner endoneurium, are bathed in "endoneurial fluid" similar to CSF but of undefined origin. CSF flow in the peripheral nervous system has not been demonstrated. Here we show CSF flow extends beyond the CNS to peripheral nerves in a contiguous flowing system. Utilizing gold nanoparticles, we identified that CSF is continuous with the endoneurial fluid and reveal the endoneurial space as the likely site of CSF flow in the periphery. Nanogold distribution along entire peripheral nerves and within their axoplasm suggests CSF plays a role in nutrient delivery and waste clearance, fundamental aspects of peripheral nerve health and disease.

One Sentence Summary

Cerebrospinal fluid unites the nervous system by extending beyond the central nervous system into peripheral nerves.

Identification of a novel path for cerebrospinal fluid (CSF) drainage of the human brain

How cerebrospinal fluid (CSF) drains from the human brain is of paramount importance to cerebral health and physiology. Obstructed CSF drainage results in increased intra-cranial pressure and a predictable cascade of events including dilated cerebral ventricles and ultimately cell death. The current and accepted model of CSF drainage in humans suggests CSF drains from the subarachnoid space into the sagittal sinus vein. Here we identify a new structure in the sagittal sinus of the human brain by anatomic cadaver dissection. The CSF canalicular system is a series of channels on either side of the sagittal sinus vein that communicate with subarachnoid cerebrospinal fluid via Virchow-Robin spaces. Fluorescent injection confirms that these channels are patent and that flow occurs independent of the venous system. Fluoroscopy identified flow from the sagittal sinus to the cranial base. We verify our previous identification of CSF channels in the neck that travel from the cranial base to the subclavian vein. Together, this information suggests a novel path for CSF drainage of the human brain that may represent the primary route for CSF recirculation. These findings have implications for basic anatomy, surgery, and neuroscience, and highlight the continued importance of gross anatomy to medical research and discovery.

Clinical Application of Stromal Vascular Fraction Gel in Temple Augmentation Using Deep Injection and Shallow Pave Filling

BACKGROUND

Temporal hollowing is an early sign of aging, and many techniques comprising the injection of fillers into the temporal fossa to correct this hollowing have been described.

OBJECTIVE

To assess the safety of a new technique in which stromal vascular fraction gel is used for temporal hollowing.

METHODS

Thirty-three patients with temporal hollowing were corrected with the aforementioned gel using deep injection and shallow pave filling at the Department of Plastic and Reconstructive Surgery, Guangdong Women and Children Hospital, China, between January 2017 and April 2021. This gel was injected into the double plane via a needle and cannula by the same cutaneous access points to prevent severe vascular injury. Improvement was evaluated by self-assessment, the Hollowness Severity Rating Scale (grade range, 0-3; lower grades represent minimal hollowness), and a satisfaction survey.

RESULTS

Self-assessment questionnaire (6 questions) results were satisfactory; 44 temples (67%) demonstrated more than 2 grades of magnitude of clinical improvement. Thirty-one patients (94%) were satisfied with their outcomes; the complaint ratio was low.

CONCLUSION

The high satisfaction rate of patients treated using the stromal vascular fraction gel by deep injection and shallow pave filling suggests that this technique is simple, effective, and safe.

LEVEL OF EVIDENCE IV

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Ventricular Infusion and Nanoprobes Identify Cerebrospinal Fluid and Glymphatic Circulation in Human Nerves

Growing evidence suggests that cerebrospinal fluid circulates in human nerves. Several conditions encountered by the plastic surgeon may be related to dysregulation of this system, including nerve transection, stretch injuries, and peripheral neuropathy. The purpose of this study was to show how ventricular infusion and nanoprobes identify CSF and glymphatic circulation in neural sheaths of human nerves.

METHODS

The technique of ventricular infusion using buffered saline was developed in 2017. The technique was used in a series of eight fresh cadavers before dissection of the median nerve, and combined with fluorescent imaging and nanoprobe injections in selected specimens.

RESULTS

Eight cadaver specimens underwent ventricular infusion. There were six female and two male specimens, ages 46-97 (mean 76.6). Ventricular cannulation was performed successfully using coordinates 2 cm anterior to coronal suture and 2.5 cm lateral to sagittal suture. Depth of cannulation ranged from 44 to 56 mm (mean 49.7). Ventricular saline infusion complemented by nanoprobe injection suggests CSF flows in neural sheaths, including pia meninges, epineurial channels, perineurium, and myelin sheaths (neurolemma).

CONCLUSIONS

Ventricular infusion and nanoprobes identify CSF flow in neural sheaths of human nerves. CSF flow in nerves is an open circulatory system that occurs via channels, intracellular flow, and cell-to-cell transport associated with glial cells. Neural sheaths, including neurolemma, may participate in glucose and solute transport to axons. These techniques may be used in anatomic dissection and live animal models, and have been extended to the central nervous system to identify direct ventricle-to-pia meninges CSF pathways.

The Value of Integrating Fluorescent Imaging and Immunohistochemistry for Future Anatomical Studies in Aesthetic Surgery: Lessons From the Cerebrospinal Fluid Circulatory System of Human Nerves and Brain

BACKGROUND

During their work on the cerebrospinal fluid (CSF) circulatory system of human nerves and brain, the authors applied imaging and tissue techniques that complemented basic anatomical dissection.

OBJECTIVES

The authors sought to show how integrating fluorescent imaging and basic immunohistochemistry (IHC) with facial anatomy can address current problems in aesthetic surgery.

METHODS

The authors developed an algorithm and a set of principles from their work on the CSF circulatory system and applied these to 3 problems in aesthetic surgery: the functional anatomy of the vermilion-cutaneous junction; chemosis; and the functional anatomy of periosteal fixation.

RESULTS

Integrating fluorescent imaging and IHC with anatomical dissection characterizes structural and functional anatomy. Fluorescent imaging helps to identify and locate easily missed structures. IHC defines cell type and function. The vermilion-cutaneous junction is defined by a major lymphatic vessel. Lymphatic flow from the medial limbus to the lateral canthus suggests the etiology of chemosis. Periosteal sites of fixation prevent shear where dural CSF vessels drain directly to subcutaneous lymphatics.

CONCLUSIONS

Integrating anatomical dissection with fluorescent imaging and basic IHC characterizes structural and functional anatomy and helps to better understand many problems encountered in aesthetic surgery.

The Superficial Temporal Artery: Anatomical Map for Facial Reconstruction and Aesthetic Procedures

BACKGROUND

The superficial temporal artery (STA), a terminal branch of the external carotid artery, supplies multiple regions of the scalp and face. Knowledge of the STA is important for reconstructive and aesthetic procedures of the head and face.

OBJECTIVES

The aim of this study was to map the STA in relation to anatomical landmarks.

METHODS

Computed tomographic head angiographies of 215 patients were included in this study; the final analysis comprised 419 STAs. The STA's main branches and variants were identified. The diameters of the STA and its frontal and occipital branches were measured, and the distance between the STA tree and anatomical landmarks was delineated.

RESULTS

Frontal and parietal branches were recorded in 98.1% and 90.7% of patients, respectively. The mean diameters, measured 1 and 7 cm from the STA bifurcation for the frontal branch, were 0.97 ± 0.32 and 0.81 ± 0.26 mm, respectively, and for the parietal branch, the diameters were 0.96 ± 0.28 and 0.76 ± 0.23 mm, respectively. The STA bifurcation point was located above the zygomatic arch (ZA) in 75.6%, below in 14.7%, and on the ZA in 9.7% of patients. The mean distance from the ZA center to the STA bifurcation was 16.8 ± 16.0 mm.

CONCLUSIONS

The STA artery and its main branches follow a conservative course, and serious anatomical variations are relatively rare. The STA and its main branches may be localized using simple anatomical landmarks. An anatomical map showing artery-free zones in the lateral forehead region was presented, which may prove useful for plastic, reconstructive, and aesthetic surgeons.

Level of Evidence: 4.

Anatomical Fat Grafting for Reconstruction of Frontotemporal Contour Deformities After Neurosurgical and Craniofacial Surgical Interventions: A Symmetry Outcome Study

BACKGROUND

Fat grafting has been described as an option to repair frontotemporal contour deformities (volumetric deficiency of bone and/or soft tissues) after neurosurgical/craniofacial surgical interventions. However, technical surgical descriptions have varied, with reports describing the bolus fat injection or the classical multilayer injection, but with no detailed descriptions concerning how and where the fat should be grafted. The purpose of this study was to assess the frontotemporal symmetry outcomes after a single fat-grafting procedure for postoperative frontotemporal contour deformity reconstructions using the anatomical fat-grafting approach.

METHODS

A prospective analysis was conducted of consecutive patients (n = 106) who underwent anatomical fat grafting (Coleman's structural fat grafting technique using anatomical facial subunit and fat compartment principles) to reconstruct frontotemporal contour deformities after neurosurgical/craniofacial surgical interventions. A subjective assessment by a panel of external surgical professionals and laypersons was obtained to grade the frontotemporal symmetry. Objective ultrasound symmetry assessment was blindly performed preoperatively and at 3- and 12-month follow-up.

RESULTS

There were significant (all P  <  0.05) postoperative subjective and objective frontotemporal symmetry enhancements (preoperative < postoperative) after anatomical fat grafting, with no differences (all P > 0.05) between the 3- and 12-month postoperative comparisons. Thirty-seven percent of patients required an additional fat grafting session for residual asymmetry after 12 months of follow-up.

CONCLUSIONS

Patients with frontotemporal contour deformities presented improved subjective and objective frontotemporal symmetry after an anatomical fat grafting session.

Anatomy of the Superficial Fascia System of the Breast: A Comprehensive Theory of Breast Fascial Anatomy

Supplemental Digital Content is available in the text.

Background:

It has been two centuries since Petrus Camper identified superficial fascia and over 175 years since Sir Astley Cooper wrote his book on the anatomy of the breast. In the 1990s, Ted Lockwood taught us the importance of the superficial fascia layers in body contouring procedures he pioneered. These descriptions, however, fail to explain the three-dimensional fascial system in the breast. The authors set out to discover and describe a theory of superficial fascia structures responsible for breast shape.

Methods:

The nature of the superficial fascia system that surrounds the breast and its attachments to the chest were studied in 12 cadaver breast dissections and in clinical cases of both cosmetic and reconstructive breast procedures.

Results:

The authors found a three-dimensional, closed system of fascia and fat surrounding the corpus mammae, which attaches to the skin by means of specialized vertical cutaneous ligaments, or Cooper ligaments, and which attaches to the chest wall by means of a three-dimensional zone of adherence at the breast’s periphery.

Conclusions:

The breast is shaped by a three-dimensional, fibrofatty fascial system. Two layers of this system surround the corpus mammae and fuse together around it, and anchor it to the chest wall in a structure we have called the circummammary ligament.