Cesare Tiengo

Histotopographic study of the fibroadipose connective cheek system.

The purpose of this study was to investigate the morphology of the superficial musculoaponeurotic system (SMAS). Eight embalmed cadavers were analyzed: one side of the face was macroscopically dissected; on the other side, full-thickness samples of the parotid, zygomatic, nasolabial fold and buccal regions were taken. In all specimens, a laminar connective tissue layer (SMAS) bounding two different fibroadipose connective layers was identified. The superficial fibroadipose layer presented vertically oriented fibrous septa, connecting the dermis with the superficial aspect of the SMAS. In the deep fibroadipose connective layer, the fibrous septa were obliquely oriented, connecting the deep aspect of the SMAS to the parotid-masseteric fascia. This basic arrangement shows progressive thinning of the SMAS from the preauricular district to the nasolabial fold (p < 0.05). In the parotid region, the mean thicknesses of the superficial and deep fibroadipose connective tissues were 1.63 and 0.8 mm, respectively, whereas in the region of the nasolabial fold the superficial layer is not recognizable and the mean thickness of the deep fibroadipose connective layer was 2.9 mm. The connective subcutaneous tissue of the face forms a three-dimensional network connecting the SMAS to the dermis and deep muscles. These connective laminae connect adipose lobules of various sizes within the superficial and deep fibroadipose tissues, creating a three-dimensional network which modulates transmission of muscle contractions to the skin. Changes in the quantitative and qualitative characteristics of the fibroadipose connective system, reducing its viscoelastic properties, may contribute to ptosis of facial soft tissues during aging.

Pectoral and femoral fasciae: common aspects and regional specializations

The aim of this study was to analyse the organization of the deep fascia of the pectoral region and of the thigh. Six unembalmed cadavers (four men, two women, age range 48–93 years old) were studied by dissection and by histological (HE, van Gieson and azan-Mallory) and immunohistochemical (anti S-100) stains; morphometric studies were also performed in order to evaluate the thickness of the deep fascia in the different regions. The pectoral fascia is a thin lamina (mean thickness ± SD: 297 ± 37 μm), adherent to the pectoralis major muscle via numerous intramuscular fibrous septa that detach from its inner surface. Many muscular fibres are inserted into both sides of the septa and into the fascia. The histological study demonstrates that the pectoral fascia is formed by a single layer of undulated collagen fibres, intermixed with many elastic fibres. In the thigh, the deep fascia (fascia lata) is independent from the underlying muscle, separated by the epimysium and a layer of loose connective tissue. The fascia lata presents a mean thickness of 944 μm (±102 μm) and it is formed by bundles of collagen fibres, arranged in two to three layers. In each layer, the fibres are parallel to each other, whereas the orientation of the fibres varies from one layer to the adjacent one. The van Gieson elastic fibres stain highlights the presence of elastic fibres only in the more external layer of the fascia lata. In the thigh the epimysium is easily recognizable under the deep fascia and presents a mean thickness of 48 μm. Both the fascia lata and pectoral fascia result innerved, no specific differences in density or type of innervations is highlighted. The deep fascia of the pectoral region is morphologically and functionally different from that of the thigh: the fascia lata is a relatively autonomous structure with respect to the underlying muscular plane, while the pectoralis fascia acts as an additional insertion for the pectoralis major muscle. Different portions of the pectoralis major muscle are activated according to the glenohumeral joint movements and, consequently, selective portions of the pectoral fascia are stretched, activating specific patterns of proprioceptors. So, the pectoralis muscle has to be considered together with its fascia, and so as a myofascial unit, acting as an integrated control motor system.

Comparison of Transverse Carpal Ligament and Flexor Retinaculum Terminology for the Wrist

PURPOSE To investigate the macroscopic anatomy and histological characteristics of the transverse carpal ligament and the flexor retinaculum of the wrist and to investigate their anatomical relationships and define appropriate terminology. METHODS The volar regions of the wrists of 30 unembalmed subjects were examined by dissection and by histological and immunohistochemical staining. In vivo magnetic resonance imaging studies were also carried out on 10 subjects. RESULTS The dissection study showed that the antebrachial fascia at the volar aspect of the wrist presents a reinforcement. From a histological point of view, it is composed of 3 layers of undulated collagen fiber bundles. Adjacent layers show different orientations of the collagen fibers. Many nerve fibers and Pacini and Ruffini corpuscles were found in all specimens. Under this fibrous plane is another fibrous structure, placed transversely between the ulnar-sided hamate and pisiform bones, and the radial-sided scaphoid and trapezium bones. The deeper fibrous structure shows completely different histological characteristics, having parallel, thicker collagen fiber bundles and few nerve fibers. Magnetic resonance images confirm the presence of 2 clearly distinguished fibrous structures in the wrist, the first in continuity with the antebrachial fascia and the second located in a deeper plane between the hamate and scaphoid. CONCLUSIONS Two different fibrous structures with different histological characteristics are present in the volar wrist: the more superficial one is in continuity with the antebrachial fascia and could be considered its reinforcement; the deeper one is composed of strong lamina, with histological features similar to those of a ligament. For these reasons, we suggest that the term transverse carpal ligament should be used to indicate the fibrous lamina connecting the hamate and pisiform to the scaphoid and trapezium and that the term flexor retinaculum of the wrist should be abandoned because it does not correspond to any specific, autonomous structure.

The gracilis muscle and its use in clinical reconstruction: an anatomical, embryological, and radiological study.

The gracilis muscle is used widely in reconstructive surgery, as a pedicled or as a free microsurgical flap, for soft tissue coverage or as a functioning muscle transfer. Many studies, based on cadaver dissections, have focused on the vascular anatomy of the gracilis muscle and provided different data about the number, origin, and caliber of its vascular pedicles. Computed tomographic (CT) angiography of both thighs of 40 patients (35 males and 5 females, mean age: 63 years) have been analyzed to provide a detailed anatomical description of the arterial supply of the gracilis muscle. The gracilis muscle had a mean length of 41 ± 2.1 cm. The principal pedicle enters the gracilis muscle at a mean distance (±SD) of 10 ± 1 cm from the ischiopubic attachment of the muscle. Its caliber shows a mean value of 2.5 ± 0.5 mm, and it is statistically larger when originating directly from the deep femoral artery (45%) than from its muscular branch supplying the adductors, i.e., the “artery to the adductors” (46%) (P < 0.01). A significant correlation between the caliber of the artery of the main pedicle and the volume of the gracilis muscle was found (P < 0.01). The mean number of distal accessory pedicles is 1.8 (range, 1–4,) and the artery of the first of these pedicles shows a mean caliber of 2.0 mm. There is no correlation between either the number or the caliber of the artery of the accessory pedicles and the volume of the gracilis muscle. CT angiography, providing detailed images of the muscular and vascular structures of the thigh of each patient, could be a useful preoperative study for the reconstructive surgeon. It would allow a personalized planning of a gracilis flap, reducing the risk of iatrogenic damage. Clin. Anat. 21:696–704, 2008.

Fascia redefined: anatomical features and technical relevance in fascial flap surgery.

Fascia has traditionally been thought of as a passive structure that envelops muscles, and the term “fascia” was misused and confusing. However, it is now evident that fascia is a dynamic tissue with complex vasculature and innervation. A definition of fascia as an integral tissue has been provided here, highlighting the main features of the superficial and deep fasciae. Wide anatomic variations and site-specific differences in fascial structure are described, coupled with results of our extensive investigations of fascial anatomy. This will enable surgeons to make better decisions on selecting the appropriate fascia in the construction of fascial flaps. The use of the superficial or deep fasciae in the creation of a fascial flap cannot be selected at random, but must be guided by the anatomical features of the different types of fasciae. In particular, we suggest the use of the superficial fascia, such as the parascapular fascio-cutaneous free flap or any cutaneous flap, when a well-vascularized elastic flap, with the capacity to adhere to underlying tissues, is required, and a fascio-cutaneous flap formed by aponeurotic fascia to resurface any tendon or joints exposures. Moreover, the aponeurotic fascia, such as the fascia lata, can be used as a surgical patch if the plastic surgeon requires strong resistance to stress and/or the capacity to glide freely. Finally, the epimysial fascia, such as in the latissimus dorsi flap, can be used with success when used together with the underlying muscles. Clearly, extensive clinical experience and judgment are necessary for assessment of their potential use.

Histological evolution of chronic wounds under negative pressure therapy

BACKGROUND Negative pressure wound therapy (NPT) has achieved widespread success in the treatment of difficult wounds. However, its effects are but partially explored, and investigations mostly concentrated at the wound-dressing interface; a detailed histological description of the evolution of wounds under NPT is still lacking. MATERIALS AND METHODS Subsequent punch biopsies of NPT-treated chronic wounds of human patients were analysed. Phenomena occurring in wounds were quantified by analysis of proliferating cells nuclear antigen (PCNA) (proliferating nuclei), CD31 (blood vessels), CD68p (macrophages) and CD45 (lymphocytes) stained slides. RESULTS Three layers were identified in day-0 wounds. Over time, under NPT, the layers behaved differently: the most superficial (1.5 mm) developed granulation tissue, constant in thickness, with high proliferation index, increased in blood vessels density and developed acute inflammation. Instead, the two deeper layers decreased in proliferation rate, maintained vessels density unchanged, were cleared of chronic inflammation and oedema and underwent progression towards stable tissue. DISCUSSION Indeed, while most research has focused on induction of superficial granulation tissue by NPT, deeper layers appear to be also affected, with relieving of chronic inflammation and tissue stabilisation. This may be an important and under-appreciated effect, playing a role in the known positive outcomes of NPT, such as better graft-taking rates.

The palmaris longus muscle and its relations with the antebrachial fascia and the palmar aponeurosis.

The palmaris longus (PL) is a muscle of the forearm with a long distal tendon that is continuous with the palmar aponeurosis (PA). It is generally assumed that the muscle lies deep to the antebrachial fascia from origin to termination, but a detailed description is lacking. The relationship of the PL tendon with the antebrachial fascia was studied in 30 dissections. The PL was completely absent in six specimens (20%), whereas the PA was identified in all. Average length of the forearm was 25.5 cm (SD: 2.1 cm, range 22–29 cm), overall length of the PL muscle 26.9 cm (SD: 2.6 cm, range 22.5–31.5 cm), muscular belly 13.8 cm (SD: 3.4 cm, range 9.5–23 cm), tendon 13.1 cm (SD: 3.3 cm, range 8–15.5 cm). Proximally, the PL was situated deep to the antebrachial fascia, then in the lower third of the forearm its tendon perforated the antebrachial fascia (at 4.7 ± 1.7 cm from the bistyloid line) moving to a suprafascial plane, inserting in the PA. The PA could be divided into two layers: the superficial one formed by longitudinal fibers and adherent to the skin, the deep one formed by transverse fibers continuous laterally with the deep fascia of the hand. The PL tendon was found to be in continuity only with the longitudinal fibers of the PA. Based on the anatomical findings, it may be suggested that the superficial part of the PA is situated in the subcutaneous planes of the palm, and that the muscle should be considered as a tensor of the superficial fascial system of the subcutaneous tissue. Clin. Anat. 22:221–229, 2009.

Reversed gracilis pedicle flap for coverage of a total knee prosthesis.

BACKGROUND Poor wound-healing and skin necrosis are potentially devastating complications after total knee arthroplasty. Primary soft-tissue coverage with a medial or lateral gastrocnemius transposition flap is typically the first choice for reconstruction. The aim of this study was to evaluate the use of a distally based secondary-pedicle flap of the gracilis muscle for reconstruction of a soft-tissue defect. METHODS The characteristics of the distally based (secondary) pedicles of the gracilis muscle were studied with use of dissection (ten cadavers) and computed tomographic angiograms (fifty patients). On the basis of the anatomical features, an extended reversed gracilis flap based on the secondary pedicles was used in three patients with severe soft-tissue complications of total knee arthroplasty. RESULTS The mean number of secondary pedicles was 1.8 (range, one to four). The pedicles originated from the superficial femoral or popliteal artery. The most proximal pedicle was often the largest (mean caliber, 2.0 mm), and its point of entry into the gracilis muscle was an average (and standard deviation) of 21 +/- 3.6 cm (range, 16 to 28 cm) from the ischiopubic branch. A significant positive association (p = 0.001; r(2) = 0.49) was found between the caliber of the proximal secondary pedicle and the number of other secondary pedicles. In all three patients, the adequate caliber of the secondary pedicles (as shown on preoperative computed tomographic angiograms) and good muscle vascularization confirmed the utility of the gracilis as a distally based pedicle flap. CONCLUSIONS For the treatment of large soft-tissue defects of the patella or the proximal part of the knee, or for soft-tissue reconstruction over an exposed total knee prosthesis, the reversed gracilis pedicle flap may be an alternative to, or may be integrated with, a lateral or medial gastrocnemius flap.

Surgical anatomy of the radial nerve at the elbow.

An anatomical study of the brachial portion of the radial nerve with surgical implications is proposed. Thirty specimens of arm from 20 fresh cadavers (11 male, 9 female) were used to examine the topographical relations of the radial nerve with reference to the following anatomical landmarks: acromion angle, medial and lateral epicondyles, point of division between the lateral and long heads of the triceps brachii, lateral intermuscular septum, site of division of the radial nerve into its superficial and posterior interosseous branches and entry and exit point of the posterior interosseous branch into the supinator muscle. The mean distances between the acromion angle and the medial and lateral levels of crossing the posterior aspect of the humerus were 109 (±11) and 157 (±11) mm, respectively. The mean length and calibre of the nerve in the groove were 59 (±4) and 6 (±1) mm, respectively. The division of the lateral and long heads of the triceps was found at a mean distance of 126 (±13) mm from the acromion angle. The mean distances between the lateral point of crossing the posterior aspect of the humerus and the medial and lateral epicondyles were 125 (±13) and 121 (±13) mm, respectively. The mean distance between the lateral point of crossing the posterior aspect of the humerus and the entry point in the lateral intermuscular septum (LIS) was 29 (±6) mm. The mean distances between the entry point of the nerve in the LIS and the medial and lateral epicondyles were 133 (±14) and 110 (±23) mm, respectively. Our study provides reliable and objective data of surgical anatomy of the radial nerve which should be always kept in mind by surgeons approaching to the surgery of the arm, in order to avoid iatrogenic injuries.

The cubital tunnel: a radiologic and histotopographic study

Entrapment of the ulnar nerve at the elbow is the second most common compression neuropathy in the upper limb. The present study evaluates the anatomy of the cubital tunnel. Eighteen upper limbs were analysed in unembalmed cadavers using ultrasound examination in all cases, dissection in nine cases, and microscopic study in nine cases. In all cases, thickening of the fascia at the level of the tunnel was found at dissection. From the microscopic point of view, the ulnar nerve is a multifascicular trunk (mean area of 6.0 ± 1.5 mm2). The roof of the cubital tunnel showed the presence of superimposed layers, corresponding to fascial, tendineous and muscular layers, giving rise to a tri‐laminar structure (mean thickness 523 ± 235 μm). This multilayered tissue was hyperechoic (mean thickness 0.9 ± 0.3 mm) on ultrasound imaging. The roof of the cubital tunnel is elastic, formed by a myofascial trilaminar retinaculum. The pathological fusion of these three layers reduces gliding of the ulnar nerve during movements of the elbow joint. This may play a role in producing the symptoms typical of cubital tunnel syndrome. Independent from the surgical technique, decompression should span the ulnar nerve from the triceps brachii muscle to the flexor carpi ulnaris fascia.