[Topographic study of the parietal region for the elaboration of revascularized cranium vault autograft]. / Izuchenie topografo-anatomicheskikh osobennostei temennoi oblasti pri razrabotke revaskulyariziruemogo kostno-fastsial'nogo temennogo autotransplantata.

OBJECTIVE: Topographic and blood vessel architecture study of the parietal area and distal regional pool of the superficial temporal artery (STA) to assess the possibility of revascularized cranium vault bone autograft formation. MATERIAL AND METHODS: For the topographic and anatomical study, 30 non-fixed corpses (17 male and 13 female) were selected, the average age of which was 59±5 years. In the anamnesis and catamnesis, there were no indications of trauma or other pathology of the head and neck, including vascular. STA was contrasted with a non-radiocontrast dye (brilliant green) with the introduction of the dye into the STA with preliminary ligation of the frontal branch of the STA. The area of blood supply to soft tissue and bone structures was studied. The angioarchitectonics of the parietal region was studied, the feeding vessel of the studied flap was identified. RESULTS: The obtained anatomical landmarks for the collection of CPFP flap make it possible to form a flap with high accuracy and minimize the morbidity of the donor area.

The parietal foramen anatomy: studies using dry skulls, cadaver and in vivo MRI.

OBJECTIVE: The aim of this study was to describe the anatomical features encountered in the parietal foramen in a series of 178 human bones and 123 head MRI examinations. A cadaveric specimen was also dissected to demonstrate the trajectory of a superficial scalp vein through the parietal foramen as far as the dura mater. A literature review was performed regarding prevalence of parietal foramen in different populations. METHODS: Totally, 178 paired adult bones were used to investigate the presence, shape and number of the parietal foramina. In addition, 123 brain MRI examinations were also studied. RESULTS: The parietal foramina were encountered in 75/89 (84.3%) skulls [32/38 (84.2%) in women vs. 43/51 (84.3%) in men, p > 0.05]. The parietal foramen was present bilaterally in 44.73% of females and 54.9% of males. Regarding unilaterality of the parietal foramen, a right or left laterality was observed in female 21% right versus 18% left; and 16% versus 14% (left) in males (p > 0.05). The accessory parietal foramen was present in the right parietal in 2.6% and in 7.9% on the left side of the females, while 5.9% and 3.9% of the males on the right or left sides, respectively. The parietal foramina located in the proximity of the sagittal suture (male 7.1 ± 2.5 mm vs. female, 7.4 ± 2.7 mm). There was a positive correlation between the right and left parietal foramina regarding the distance from the median line. The distance from a foramen to the contralateral one was 16 ± 4 mm in men and 18 ± 5 mm in women, respectively (p > 0.05). CONCLUSION: No major differences were encountered between sexes regarding the anatomical features of parietal foramen.

Vascularized Composite Parietal Bone Flap for Immediate Reconstruction of a Hemi-Maxillectomy Defect in an Infant.

BACKGROUND: Surgical resection of maxillary tumors can result in defects that can be difficult to reconstruct by conventional means due to the complex functional and anatomic nature of the midface and lack of regional bone flap options in the head and neck. Many reconstructive methods have been used to repair maxillary defects, but the ideal technique for the reconstruction of hemi-maxillectomy defects in growing pediatric patients has yet to be determined. METHODS: The authors present a rare pediatric patient with melanotic neuroectodermal tumor of infancy resulting in a hemi-maxillectomy defect after resection that was reconstructed using a pedicled vascularized composite flap consisting of temporalis muscle, pericranium, and parietal bone. RESULTS: The patient achieved successful long-term bony reconstruction of his right maxilla with this flap. Stable skeletal fixation with adequate orbital support was maintained over a >3-year follow-up period. CONCLUSION: A vascularized composite parietal bone flap is a reliable reconstructive option for reconstruction of large maxillectomy defects providing low donor-site morbidity, adequate globe support, excellent long-term skeletal stability, and malar symmetry in rapidly growing pediatric patients. Successful reconstruction for a rare patient with maxillary melanotic neuroectodermal tumor of infancy requiring hemi-maxillectomy was demonstrated with >3-year follow-up.

Reversible Alopecia with Localized Scalp Necrosis After Accidental Embolization of the Parietal Artery with Hyaluronic Acid.

Hyaluronic acid (HA) filler injection is widely used for soft-tissue augmentation. Complications associated with HA filling are not uncommon; however, HA-induced alopecia is a rarely reported complication that could result in severe secondary psychological trauma. The etiology, clinical traits, treatment strategies, outcomes, and possible reversibility of HA-induced alopecia have not been characterized. Here, we report a case in which bilateral temple injections of 6.5 mL of HA led to persistent pain over the left scalp for several days. Although the pain was relieved at day 9 after 600 U of hyaluronidase were injected in the left temple, the patient developed localized alopecia at the left temporoparietal region with central skin necrosis at day 15. After topical applications of recombinant bovine basic fibroblast growth factor gel and 2% minoxidil spay, the necrotic skin wound was healed at day 42. Hair regrowth and normal hair density were restored at day 74. Analyses of Doppler ultrasound examinations and histopathology of the skin biopsy suggested that mild ischemia of the left temporoparietal region led to reversible alopecia, while the permanent hair loss in the left parietal area was associated with severe skin ischemia. Therefore, the key to treatment would be to focus on the effective correction of severe ischemia-induced skin necrosis to prevent permanent hair loss. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effects of nonvascularized versus vascularized bone grafting on calvarial defect healing.

It remains unknown whether bone graft vascularity influences calvarial healing. The purposes of this study were (1) to develop a model to study nonvascularized and vascularized calvarial grafts as well as (2) to compare effects of bone graft vascularity on calvarial healing. Bilateral calvarial defects were created in 26 Wistar rats. The defects were left empty within 1 parietal region. On the contralateral side, the defects were partially closed with native parietal bone (control group, n = 6), nonvascularized (N-V, n = 10), or vascularized bone grafts (VAS, n = 10). The vascularized grafts were supplied by perforating dural arterioles. Bone mineralization and healing patterns from serial microcomputed tomographic scans were compared within and across the groups using parametric and nonparametric tests. Differences in bone mineral content across sides were significant between the groups at weeks 6 (P = 0.016) and 12 (P = 0.025). Bone formation was greater within both the control and VAS groups versus the N-V group at weeks 6 and 12 (P < 0.05). Healing patterns differed between the groups (P < 0.05), progressing through islands of new bone formation within the control and VAS groups while limited to defect margins on the N-V graft side. In conclusion, a bilateral calvarial defect model was established to study bone graft vascularity. Bone quantity and healing patterns differed in the presence of the nonvascularized versus vascularized grafts. Although the calvarial defect model is often applied within the plastic surgery literature to study bone substitutes, greater understanding of basic mechanisms influencing calvarial healing is first needed to avoid confounding results.

Endogenous cell therapy improves bone healing.

BACKGROUND: Although bone repair is often a relatively rapid and efficient process, many bone defects do not heal. Because an adequate blood supply is essential for new bone formation, we hypothesized that augmenting new blood vessel formation by increasing the number of circulating vasculogenic progenitor cells (PCs) with AMD3100 and enhancing their trafficking to the site of injury with recombinant human parathyroid hormone (rhPTH) will improve healing. METHODS: Critical-sized 3-mm cranial defects were trephined into the right parietal bone of C57BLKS/J 6 mice (N = 120). The mice were divided into 4 equal groups (n = 30 for each). The first group received daily subcutaneous injections of AMD3100 (5 mg/kg). The second group received daily subcutaneous injections of rhPTH (5 mg/kg). The third group received both AMD3100 and rhPTH. The fourth group received subcutaneous injections of saline. Circulating vasculogenic PC numbers, new blood vessel formation, and bony regeneration were assessed. Progenitor cell adhesion, migration, and tubule formation were assessed in the presence of rhPTH and AMD3100. RESULTS: Flow cytometry demonstrated that combination therapy significantly increased the number of circulating PCs compared with all other groups. In vitro, AMD3100-treated PCs had significantly increased adhesion migration, and tubule formation was assessed in the presence of rhPTH. Combination therapy significantly improved new blood vessel formation in those with cranial defect compared with all other groups. Finally, bony regeneration was significantly increased in the combination therapy group compared with all other groups. CONCLUSIONS: The combination of a PC-mobilizing and traffic-enhancing agent improved bony regeneration of calvarial defects in mice.

Micro-CT observation of angiogenesis in bone regeneration.

OBJECTIVES: Restoration of an adequate blood supply is essential for the bone healing process and is key to the success of bone augmentation procedures. In this study, we evaluated angiogenesis in rat calvarial flat bone defects using in vivo microfocus computed tomography (micro-CT). MATERIALS AND METHODS: Twenty rats were used. The calvarium was exposed and calvarial bone defects of critical (5-mm diameter) and non-critical (2.7-mm diameter) sizes were prepared. Bone regeneration and angiogenesis were evaluated by image analysis using micro-CT and histological examination. RESULTS: Critical- and non-critical-sized calvarial bone defects showed bone regeneration and angiogenesis around the midsagittal suture. Critical-sized calvarial bone defects showed approximately 1.2% reossification of the original surgical defect, whereas the non-critical-sized defects showed approximately 43.3% reossification at day 28. Furthermore, angiogenesis was observed later in the critical-sized calvarial bone defects (about 38.2%), whereas angiogenesis was observed early in the non-critical-sized calvarial bone defects (about 75.5%) at day 28. New blood vessel networks were observed around defects of both sizes. CONCLUSIONS: Angiogenesis preceded bone regeneration around critical- and non-critical-sized calvarial bone defects. Angiogenesis led to full bone formation in non-critical-sized defects.

FGF-2 angiogenesis in bone regeneration within critical-sized bone defects in rat calvaria.

OBJECTIVE: This study examined the effect of basic fibroblast growth factor (FGF)-2 with an absorbable collagen sponge on angiogenesis and bone regeneration in rat calvarial critical-sized bone defects using microcomputed tomography. METHODS: Forty 7-week-old male Fischer rats were used. The symmetrical critical-sized calvarial bone defects (5 mm diameter) were created. An absorbable collagen sponge with or without FGF-2 (0.1% or 0.3%) was implanted into each bone defect. RESULTS: Blood vessel and bone volumes were significantly higher in the 0.3% FGF-2 group compared with the control and 0.1% FGF-2 groups on day 28. Significantly more osteoblast- and osteoclast-like cells were seen in the 0.3% FGF-2 group. CONCLUSIONS: Thus, FGF-2 increased blood vessel and bone formation in rat calvarial critical-sized bone defects.

Anatomic bases of superficial temporal artery and temporal branch of facial nerve.

The superficial temporal artery (STA)-based flaps have been used for different reconstructive purposes. These operations may cause facial nerve injury. The variations of the STA and its relation to temporal branch of the facial nerve (TBFN) were evaluated in this study. Thirteen cadavers with 26 STA and TBFN have been dissected. The bifurcation of STA was found to be 60% above the superior border of the zygomatic arc and 40% below this level. The mean lengths of frontal and temporal branches (FB and TB) of STA were 11.5 and 11.4 cm, respectively. The mean numbers of perforators of FB and TB to deep plane were 1.30 and 1.34, respectively. The mean diameter of STA at the superior border of zygomatic arc was 2.5 mm. The mean diameters of TB and FB at the level of bifurcation were 1.8 mm and 2.0 mm, respectively. The mean number of TBFN at the level of zygomatic arc was 3.70. The mean distance of the first and last branching of TBFN to tragus was found to be 24 mm. The mean number of TBFN at the level of the middle orbita was found to be 2.7. The mean distance of first and last branches of TBFN to the lateral orbital rim was 12 and 24 mm, respectively. The results found in this study may increase the accuracy of flaps based on STA and decrease the risk of facial nerve paralysis during these operations.

The diploic venous system: surgical anatomy and neurosurgical implications.

OBJECT: There are few systematic investigations of the dissected surgical anatomy of the diploic venous system (DVS) in the neuroanatomical literature. The authors describe the DVS relative to different common neurosurgical approaches. Knowledge of this system can help avoid potential sources of unacceptable bleeding and may impact healing of the cranium. METHODS: Using a high-speed drill with a 2-mm bit, the authors removed the outer layer of the compact bone in the skull to expose the DVS in 12 formalin-fixed cadaver heads. Pterional, supraorbital, and modified orbitozygomatic craniotomies were performed to delineate the relationship of the DVS. RESULTS: The draining point of the frontal diploic vein (FDV) was located near the supraorbital notch. The draining point of the anterior temporal diploic vein (ATDV) was located in all pterional areas; the draining point of the posterior temporal diploic vein (PTDV) was located in all asterional areas. The PTDV was the dominant diploic vessel in all sides. The FDV and ATDV could be damaged during supraorbital, modified orbitozygomatic, and pterional craniotomies. The anterior DVS connected with the sphenoparietal and superior sagittal sinus (SSS). The posterior DVS connected with the transverse and sigmoid sinuses and was the dominant diploic vessel in all 24 sides. Of all the major diploic vessels, the location and pattern of distribution of the FDV were the most constant. The parietal bone contained the most diploic vessels. No diploic veins were found in the area delimited by the temporal squama. CONCLUSIONS: The pterional, orbitozygomatic, and supraorbital approaches place the FDV and ATDV at risk. The major anterior diploic system connects the SSS with the sphenoparietal sinus. The posterior diploic system connects the SSS with the transverse and sigmoid sinuses.

Combined surgical and endovascular treatment of a spontaneous diploic arteriovenous fistula. Case report.

The authors report on the case of a 28-year-old woman presenting with an intraosseous arteriovenous fistula (AVF) located in the left parietal bone. The fistula was formed by direct arteriovenous shunts connecting branches of the left middle meningeal and superficial temporal arteries with a parietal diploic vein. Drainage occurred through both the external and internal jugular venous systems. Therapy consisted of combined surgical and endovascular approaches. The results of a pathological examination of the resected AVF showed mild enlargement of the diploic space. The angiographic appearance, pathological anatomy, and treatment of this rare lesion are discussed, as is a possible relationship between diploic AVFs and the development of aneurysm bone cysts.

John Howship (1781-1841) and growing skull fracture: historical perspective.

In the late 18th and early 19th centuries, Dr. John Howship, a pioneering British surgeon, described the clinical features and pathophysiology of various surgical disorders of the human body. His critical contributions to pediatric neurosurgery came in 1816 when he first described the features of an important childhood condition following head trauma, what he referred to as parietal bone absorption. This condition as depicted by Dr. Howship was soon to be christened by later scholars as traumatic cephalhydrocele, traumatic meningocele, leptomeningeal cyst, meningocele spuria, fibrosing osteitis, cerebrocranial erosion, and growing skull fracture. Nevertheless, the basic features of the condition as observed by Dr. Howship were virtually identical to the characteristics of the above-mentioned disorders. This article describes the life and accomplishments of Dr. Howship and his contributions to the current understanding of growing skull fracture.

Anatomy of the superficial temporal artery.

The anatomy of the superficial temporal artery was investigated in radiographic and cadaveric studies. The superficial temporal artery divides into an anterior and posterior branch, and the diameters of these vessels are similar. The anatomy of these two vessels is described, and implications for their use in reconstructive flaps are suggested.

Bilateral diploic arteriovenous fistula causing scalp hematoma.

The authors report an unusual case of an extensive spontaneous subgaleal hematoma caused by a bilateral arteriovenous shunting lesion involving the diploic veins. The enlarged diploic canals and the existence of bilateral diploic arteriovenous shunts with no history of fracture or trauma indicate that these fistulas developed spontaneously over a long period of time. Angiographic findings in these unusual arteriovenous shunting lesions and their endovascular management are briefly illustrated. A case of a bilateral diploic fistula has not been reported before and it may contribute to the understanding of the diversity of dural arteriovenous shunting lesions.

Primarily infected cephalhematoma and osteomyelitis in a newborn.

Cephalhematomas are subperiosteal blood collections occurring in newborns secondary to trauma at birth. They develop within a few days and are subsequently resorbed. Infection of a cephalhematoma is unusual and caused most often by colonization of the hematoma during bacteremia or by direct inoculation secondary to trauma. Less than 10 patients with primary infection of the hematoma, in the absence of a positive blood culture, complicated by osteomyelitis have been described. We report a newborn with a primarily infected cephalhematoma complicated by parietal bone osteomyelitis.

Influence of particle size of autogenous bone grafts on the early stages of bone regeneration: a histologic and stereologic study in rabbit calvarium.

PURPOSE: The aim of this study was to investigate the influence of particle size of autogenous bone grafts on the early stages of bone regeneration. MATERIALS AND METHODS: Bicortical skull bone defects were prepared in 15 rabbits (4 in each rabbit). Two defects were filled at random with either small (0.5 to 2 mm3) or large (10 mm3) autogenous bone particles. In addition, 1 defect was left unfilled (control defect). All defects were covered bicortically by expanded polytetrafluoroethylene membranes. The animals were divided randomly into 3 groups and sacrificed after 1, 2, and 4 weeks, respectively. Histologic and stereologic evaluations were performed after the sections were blinded. RESULTS: No significant differences in total vessel surface area could be identified among the 3 groups. The total volume of newly formed bone in defects with small particles was larger and more mature compared to defects with large particles after 2 and 4 weeks. Furthermore, the resorption of small particles was more pronounced after 4 weeks, documenting a higher level of bone substitution compared to large particles. DISCUSSION: The early stages of bone regeneration were influenced by the particle site of autogenous bone grafts. CONCLUSION: The present study indicated that particles of 0.5 to 2 mm3 in size should be preferred to particles of 10 mm3 in size for bone grafting.

Vascularized parietal bone flaps. A new dimension in mandibular reconstruction.

The ultimate objective, when treating a mandibular defect, is to restore completely the function and cosmetic appearance of the face. The reconstruction must include bone from a similar source, good in quality and shape and living, to resist infection and the continuous stress that takes place in the mandible during mastication. Our technique for mandibular reconstruction using bone from the calvarium, of full thickness to receive implants and living because it is pedicled on the galea (from the superficial temporal artery) is reported. Our criteria for reconstruction, and the analysis of all the cases reconstructed with the technique mentioned above, is presented. Emphasis is placed on the good shape of this bone flap, its vascularization studies (compared with those in other techniques) and the high rate of success in both cosmetic and functional results.

Vascularized cranial bone grafts for mandibular and maxillary reconstruction. The parietal osteofascial flap.

The authors have performed 13 cases of vascularized cranial bone grafts for reconstruction of maxillofacial defects since 1986. Two types of flaps were used: the parietal osteofascial flap pedicled to the parieto-temporal fascia based on the superficial temporal artery and the temporalis osteomuscular flap pedicled to the temporalis muscle based on the deep temporal artery. Zygomatico-orbital complex, maxilla and mandible were reconstructed and hemifacial microsomia was also treated. The results of vascularized cranial bone grafts pedicled to fascia were as good as those of grafts pedicled to muscle. There were no major complications. Two types of vascularized cranial bone grafts seem to be useful in reconstruction of maxillofacial defects with avascular recipient beds because of their good blood supply. The parietal osteofascial flap has additional advantages including easy rotation of the flap to the defect, particularly a mandibular defect, and versatile use of fascia without bulkiness for reconstruction of soft tissue defects. This flap can be designed as a full- or partial-thickness cranial bone graft with good vascularity. In this paper, our technique for mandibular and maxillary reconstruction using the parietal osteofascial flap is introduced, and the results compared with our temporalis osteomuscular flap technique are reported.

Bone wax as a cause of a foreign body granuloma in a cranial defect: a case report.

Bone wax was used to stop bleeding of the diploic vessels after harvesting cranial bone for reconstruction of an orbital floor defect. After five months a fistula in the overlying skin of the donor site appeared and was eventually surgically explored. Remnants of bone wax and surrounding inflammatory tissue were removed and the fistula was excised. Histological examination revealed a foreign body granuloma. The use of bone wax and possible alternative local haemostatic agents and their complications are discussed.