Vascular tumors of the mouth and jaws

Oral and maxillofacial tumours in children and adolescents: Clinicopathologic audit of 75 cases in an academic medical centre, Sokoto, Northwest Nigeria

BACKGROUND

Maxillofacial tumours in children and adolescents have been documented worldwide; however, few studies were reported from Africa, especially sub-Saharan Africa. In Nigeria, most of the studies emanated from the Southwest region.

AIM

To present an audit of clinicopathologic features and treatment of orofacial tumours in children and adolescents in Sokoto, Northwest Nigeria.

PATIENTS AND METHODS

Clinicopathologic records of the Departments of Dental and Maxillofacial Surgery, Paediatrics and Histopathology, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria, were reviewed for all the oral and maxillofacial tumours managed in children <19 years from January 2011 to December 2015.

RESULTS

Two hundred and twenty-two tumours were noted in all age groups during the study duration and 75 (33.8%) of these occurred in children and adolescents. A total of 45 (60%) males and thirty (40%) females constitute the patient population with a male to female ratio of 1.5:1. There are 32 (42.7%) benign tumours and 43 (57.3%) malignant tumours. Burkitt's lymphoma was the most common malignant tumour in 24 cases (55.8%), whereas pleomorphic adenoma was the most common benign soft tissue tumour in 4 cases (30.8%) and fibro-osseous lesions were the most common benign jaw tumours in 10 cases (52.6%). Chemotherapy alone was the treatment modality in 24 cases of malignant tumour whereas 13 cases had combination chemotherapy and irradiation.

CONCLUSIONS

Our findings established that oral and maxillofacial tumours in children and adolescents are quite common in Sokoto, Northwest region of Nigeria, particularly the malignant types. There is a need for improved universal healthcare insurance for all citizens to adequately manage these children effectively.

Capillary haemangioma on the palate: a diagnostic conundrum

Haemangiomas are benign tumours of blood vessel origin and are classified as capillary, cavernous or central. They appear as flat or raised reddish-blue lesions and are generally solitary, affecting women in younger age groups. The tumour may be slowly progressive, involving extensive portions of the superficial and deep blood vessels, and affect function, depending on location. They are common in the head and neck region but rarely in the oral cavity. Oral lesions generally appear on the lips, buccal mucosa and tongue, but rarely on the palate. As the lesion can be confused with pyogenic granuloma, histopathological examination is important for a final diagnosis. The case presented here signifies a rare location of a capillary haemangioma on the palate in a middle aged man. The lesion was diagnosed by histopathology after surgical excision.

Surgical and Laser Treatment of Hemangiomas of the Lips

INTRODUCTION

Single or multiple cavernous hemangiomas involving the lips can be disfiguring and are subject to traumatic hemorrhage and ulceration. Furthermore, the cavernous hemangiomas may increase in size over time. The lip is a unique body tissue because of the vermilion color. Thus, surgical removal of lesions involving the vermilion borders present esthetic concerns.

CASE PRESENTATION

A 51-year-old male presented with a chief complaint of a "red-blue puffy" and protruding lower lip of several years duration. Clinical examination revealed four raised soft tissue lesions ranging from 0.4 to 1 cm in diameter. Similar lesions were noted on the dorsal tongue surface. All lesions blanched on palpation but were not pulsatile. The preliminary diagnosis was cavernous hemangioma. Given the range in size, distribution, and esthetic concerns, the two largest lip lesions were surgically excised and the smallest was ablated by carbon dioxide laser irradiation. A small lesion involving both lips at the commissure was not treated because of lack of esthetic and functional concerns.

CONCLUSIONS

Treatment was successful in that no complications were incurred and the esthetic result was pleasing to the patient. This case demonstrates that laser ablation of a cavernous hemangioma with good hemostasis is possible and should be considered a viable treatment option.

Intraosseous hemangiomas

Intraosseous hemangiomas are classified as benign tumors of vascular nature. Some authors describe them as hamartomas. They originate and expand inside bone structures. They are usually congenital, rarely of posttraumatic origin. In the Maxillo-Facial Surgery departments of the Universities of Rome "La Sapienza" and "Tor Vergata," from 1990 to 2004, 11 cases of intraosseous hemangioma have been diagnosed. In 6 cases, the neoplasm localized in the zygomatic region; in 3 cases, at the mandible level; in 1 patient, in the maxillary site; and in 1 patient, in the frontal bone. Literature review and the case of a male patient affected by left orbitozygomatic hemangioma are described.

Hemangiopericytoma of thoracic spine: a rare bony tumor

CASE REPORT

We report the case of a 16-year-old girl who developed hemangiopericytoma of the thoracic spine; the main clinical symptoms were of spastic paraparesis with sensory involvement and uro-fecal incontinence. She was initially put on antitubercular treatment keeping in mind the endemicity of tuberculosis in the region. When she deteriorated on conservative management, she was operated upon, and the histopathological report was suggestive of hemangiopericytoma.

MATERIALS AND METHODS

Additional immunocytochemistry was performed in the paraffin-embedded tumor sections.

CONCLUSIONS

An extremely rare case of primary epidural malignant hemangiopericytoma of the thoracic spinal column is described. It is a rare tumor, which is locally aggressive, and a potentially malignant tumor. The tumor is more commonly found in the cranium, and spinal involvement is rare, and only few case reports could be retrieved from the literature. We discuss the clinical profile, management, and outcome of spinal hemangiopericytomas along with pertinent review of the literature.

Orofacial tumours in suburban Nigerian children and adolescents

We report the type and distribution of orofacial tumours in south-western Nigerian children and adolescents. The 512 records of patients with oral and maxillofacial tumours in the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, from 1991 to 2001, were searched and the 146 records (28%) of patients aged 19 years and less were reviewed. Their mean age was 10 years (female:male ratio 1:1.4). Of the 146 tumours 74 (51%) were malignant and 72 (49%) were benign. Of the latter 31 were from soft tissue and 41 were from the jaw (20 odontogenic and 21 non-odontogenic). The most common benign soft tissue and jaw tumours were gingival epulis and ameloblastoma respectively. Of the malignant tumours 67 were lymphomas, 5 sarcomas and 2 carcinomas.

Oral and maxillofacial tumours in north Jordanian children and adolescents: a retrospective analysis over 10 years

This study evaluates the types and distribution of oral and maxillofacial tumours in north Jordanian children and adolescents. The records of the Department of Pathology at Jordan University of Science & Technology, during the period 1991-2000, were reviewed for patients younger than 19 years with oral and maxillofacial tumours. The tumours were analysed for age, sex, site and type. Out of all maxillofacial tumours, 23% occurred in children and adolescents, of these 10% were malignant and 90% were benign. 73% of the latter were soft tissue tumours and 17% were jaw tumours (58% odontogenic and 42% non-odontogenic). The most common benign soft tissue and jaw tumours were haemangioma and odontoma, respectively. 58% of malignant tumours were sarcomas and 42% were carcinomas. The mean age was 11 years with a female to male ratio of 1:1.2. The intraoral and extraoral sites most commonly affected by benign soft tissue tumours were the lower lip and face, respectively. While the total number of benign jaw tumours was slightly larger in the maxilla than the mandible, odontogenic tumours were more in the maxilla, and nonodontogenic tumours were more in the mandible. Differences found in this study between Jordanian children and adolescents and those from other countries may be attributable to genetic and geographic differences. The majority of benign tumours in the young are probably developmental rather than true neoplasms.

Hereditary intraosseous vascular malformation of the craniofacial region: an apparently novel disorder

Primary intraosseous vascular anomaly, previously called intraosseous hemangioma, is a very rare malformation that is usually seen in the vertebral column and in the skull. It is exclusively described in sporadic cases and no hereditary component has yet been reported. The most commonly affected bones in the skull are the mandible and the maxilla, and life-threatening bleeding after a simple tooth extraction is frequently observed. Here, we report two consanguineous families containing a total of four affected patients manifesting primary intraosseous vascular malformation (VMOS (vascular malformation osseous)) of the craniofacial region. The phenotypic expression is remarkably similar in both families. The characteristic findings include severe blood vessel expansions within the craniofacial bones and midline abnormalities such as diastasis recti, supraumbilical raphe, and hiatus hernia. Malformation is restricted to the mandibular and maxillary area in the prepubertal age, and rapid expansion starts after age 12 or 13. A 15-year follow-up of one of the patients demonstrated that the vascular malformation did not extend beyond the craniofacial region despite severe involvement of almost all bones in the skull. Detailed clinical and radiological evaluation provided neither evidence of soft-tissue involvement nor any sign of gross arterial, venous, or combined malformations, indicating that bone changes are a primary rather than a secondary effect due to any other vascular anomaly in the craniofacial region. An antibody against a universal proliferation marker, Ki-67, detected nonproliferative, single-layered endothelial cells, suggesting that this abnormality is a vascular malformation rather than a hemangioma. alpha-actin staining (antibody against perivascular tissue such as smooth muscle cells (SMCs) and/or pericytes) demonstrated that pathologic vessels lost their surrounding supportive tissues, as was previously seen in other types of vascular anomaly. Homozygosity mapping excluded the following loci and/or genes: multiple cutaneous venous malformation (VMCM1; gene, TIE2) on chromosome 9p21; venous malformation with glomus cells (VMGLOM) on chromosome 1p22-p21; hereditary hemorrhagic telangiectasia type 1 (HHT1; gene, endoglin) and type 2 (HHT2; gene, activin) on chromosomes 9q34.1 and 12q11-q14, respectively; and cerebral cavernous malformation type 1 (CCM1; gene, KRIT1), type 2 (CCM2), and type 3 (CCM3) on chromosomes 7q11.2-q21, 7p15-p13, and 3q35.2-q27, respectively. To the best of our knowledge, this is a new disorder, which we call hereditary intraosseous vascular malformation of the craniofacial region.

Oral and maxillofacial tumours in children: a review

This retrospective review presents our experience of oral and maxillofacial tumours in children. The subjects were 250 children under the age of 15 years (out of a total of 2747 patients with oral and maxillofacial tumours), who were treated after histopathological confirmation of their diagnoses during the 28 years 1965-92. Diagnosis, incidence, and age at presentation were the main outcome measures and the results showed that 232 patients (93%) had benign tumours and 18 (7%) were malignant. The most common benign tumour was haemangioma (n = 69) and the most common malignant tumour sarcoma (n = 14). The most common odontogenic tumour was odontoma (n = 47) and non-odontogenic tumour ossifying fibroma (n = 5). The most common site of soft tissue tumours was the tongue (n = 65) and of bony tumours the mandible (n = 62). About a third of the tumours developed in patients between the ages of 6 and 11 years. Most of the angiomas developed in patients less than 6 years old, and most of the ameloblastomas in those over 12 years of age. Children accounted for 55% of patients with lymphangoma, 41% of those with odontoma, and 22% of those with haemangioma. It is concluded that most of these lesions were probably developmental malformations rather than neoplasms, and that the definition of oral and maxillofacial tumours in children should be reconsidered.

Transpalatine excision of a cavernous hemangioma of the infratemporal fossa

Hemangiomas of the head and neck region can represent a therapeutic challenge depending on their size, location and symptoms. We report a case of a 40-year-old woman who presented with a 2-cm encapsulated cavernous hemangioma in the infratemporal fossa (ITF). Extensive workup included CT, MRI and angiography. A transoral/transpalatine approach avoiding osteotomy was used for surgical excision. After an unremarkable postoperative course the patient has remained disease-free after a 2-year follow-up period. We suggest this surgical approach as an alternative in carefully selected cases of circumscribed small, benign lesions of the ITF.

An unusual vascular hamartoma on the gingiva of an 11-year-old boy

A case is reported of an unusual vascular lesion on the gingiva of an 11-year-old boy which clinically and histopathologically did not fit well into any current classification of vascular lesions. The lesion presented as a firm nodular swelling of the buccal and lingual gingiva which had been present for 9 years. The term endovascular papillary haemangioma is suggested. Histopathologically it had features in common with a number of benign vascular lesions, as well as with some more sinister locally-aggressive vascular tumours and angiosarcomas. It is stressed that, although some of these lesions may display features suggestive of malignancy, care should be exercised when making this diagnosis, as in recent years there has been an increase in the recognition and characterization of benign vascular lesions which exhibit unusual features.

Pedunculated cavernous hemangioma. A case report

A rare case of pedunculated hemangioma of the oral mucosa has been reported. Clinically, it was diagnosed as a fibroma induced by irritation, but histologic examination followed to excisional biopsy demonstrated that it was a cavernous hemangioma.

Central hemangioma of the mandible

Central hemangioma of the mandible is a relatively rare condition; when it occurs, the clinical and radiographic presentation are often nonspecific. A proper diagnosis can be made with a high level of clinical suspicion, and imaging studies such as angiography can confirm the suspicion that a vascular lesion exists and can contribute valuable information to the preoperative data base. We report three cases of central hemangioma of the mandible demonstrating the variability of signs and symptoms and review the various treatment alternatives in the literature. We suggest that the treatment of choice for this entity is surgery, including reconstruction as necessary.

Intraosseous hemangioma of the zygomatic bone. A case report

Intraosseous hemangiomas of the facial skeleton are infrequently seen, with most cases occurring in the mandible and maxilla. Hemangioma of the zygomatic bone, however, is extremely rare. A case is presented in which selective embolization, resection of the tumor, and immediate reconstruction were carried out.

Haemangioma of the Zygoma. Report of two cases with a review of the literature

Zygomatic haemangioma is a rare benign neoplasm occurring most frequently in adult females. The authors, after reviewing the available literature, report two cases which presented with a swelling of the zygoma. Resection of the neoplasm, immediate reconstruction with cranial bone grafts and internal rigid fixation was the treatment of choice. Results two years after surgery are presented.

Intramuscular hemangioma in the oral region: report of three cases

The occurrence of intramuscular hemangioma in an intraoral or perioral localization is rare, and a thorough knowledge of these tumors is necessary for adequate diagnosis and treatment. Three cases are presented with discussion, and their histopathology and differential diagnosis are discussed. An adequate primary excision is necessary to avoid recurrence.

Capillary hemangioma of the maxilla. A report of two cases in which angiography and embolization were used

This article presents two clinical cases of capillary hemangiomas of the maxilla. Such lesions are rare, as demonstrated by the review of the literature included in this article. The presentation, differential diagnosis, histopathology, management, and follow-up for each case are discussed. Our rationale for approaching these types of lesions, as well as our opinion that microembolization should be considered as a first line approach to treatment, is presented.

Cavernous hemangioma of the zygoma: report of cases

Osseous hemangiomas of the facial bones are rare lesions, with most cases occurring in the maxilla and mandible. Reported cases in the zygoma are sparse. Two cases of zygomatic hemangiomas with widely differing presentations are reported. One case in a neonate required surgery to prevent fatal hemorrhage, and the other in an adult required correction of a cosmetic deformity. Each patient presented with a second congenital anomaly. Therapeutic problems associated with these lesions and their management are discussed.

Arteriovenous malformation of the maxillary sinus: an unusual clinical presentation

Arteriovenous (AV) malformation is a rare vascular lesion of the jaws with a benign clinical presentation. As a result, AV malformation may be excluded from a presurgical differential diagnosis, with catastrophic results. Review of the pertinent literature showed no documentation of AV malformation in the maxillary sinus, and therefore we present the case of a 43-year-old white man with a history of blunt trauma to the paranasal region, whose differential diagnosis included a vascular lesion.

Treatment of a central arteriovenous malformation of the mandible with cyanoacrylate: a 4-year follow-up

Large arteriovenous malformations of the jaws are relatively rare, potentially life-threatening lesions. When the lesion is not suspected, extraction of teeth can be fatal. The occurrence and treatment of arteriovenous vascular communications in the head and neck region have traditionally presented most perplexing problems. Traditional treatment has usually involved the obtaining of proximal and distal vascular control and surgical removal of the lesions, when feasible. This article presents a case that is of particular interest because it illustrates the successful use of cyanoacrylate as the only treatment for a large arteriovenous malformation of the left side of the mandible. A 4-year follow-up shows no evidence of the lesion and demonstrates complete regeneration of bone in the same area.

Pyogenic granuloma: evaluation of oral conditions

A consecutive series of 43 pyogenic granulomata in the oral cavity is presented. Most were located to the marginal vestibular gingivae and only a minority (12%) of these had a history of trauma whereas 70% in extragingival locations had a previous history of injury. On the basis of an evaluation of oral conditions the aetiology and the pathogenesis of the pyogenic granuloma are discussed. Trauma, microtrauma due to toothbrushing and gingival inflammation seem to be pathogenetic elements. It is suggested that the granuloma is a localised tissue response to a non-specific irritant.

Metastatic hemangioendotheliosarcoma of the mandible: report of case

Hemangioendotheliosarcoma rarely involves the oral region; 53 cases have been reported since 1980. This report presents a case of metastatic hemangioendotheliosarcoma of the mandible diagnosed in a 16-year-old boy, with a discussion of the clinical, morphologic, and histochemical findings.

Oral exophytic lesions in 23,616 white Americans over 35 years of age

This study provides the first detailed epidemiologic analysis of benign oral soft tissue masses and bony prominences. Of 1,453 such lesions found in 23,616 white persons over 35 years of age, the most common were palatal and mandibular tori, with a combined prevalence rate of 27.1 lesions/1,000 persons. Other lesions commonly found were irritation fibromas (12.0 lesions/1,000 population); hemangiomas (5.5/1,000); papillomas (4.6/1,000); epulides fissurata (4.1/1,000); mucoceles (2.5/1,000); and others. The prevalence of all oral masses was 61.4/1,000 (33.5 if bony lesions are excluded). Sex-specific and site-specific clinical information is offered and is contrasted with the literature.

Oral presentation of disseminated angiosarcoma

Angiosarcoma is a rare tumour of vascular endothelium seen most commonly on the skin. particularly the scalp. Only 4% occur in the pharynx, oral cavity or paranasal sinuses, either as primary or metastatic disease. As a mode of presentation, oral bleeding is also very rare, but is a grave sign and usually indicates widespread disease. A rapidly fatal case is presented, including post-mortem material, which illustrates many of the features of this rare oral tumour.

Haemangioma of the zygoma presenting as a tumour in the maxillary sinus

A case of haemangioma of the zygomatic bone is presented. The presenting symptoms and signs of this case, unlike those of the other five cases described in the English literature, were of an antral tumour. The treatment comprised surgical removal through a Caldwell-Luc approach. Clinical and histopathological considerations are discussed.

Maxillary angiosarcoma

A malignant tumor of mesenchymal origin, angiosarcoma, is a rare entity deriving from the endothelium of the blood vessels, that very infrequently is encountered in the jaws. 46 such cases have only been reported.

Arterial embolisation in the treatment of central haemangiomas of the maxilla. Report of two cases

The recent refinement of super-selective angiography and subsequent embolisation offer new promising possibilities in the treatment of central haemangiomas in the maxillo-facial area, either as a pre-operative measure allowing safer surgical removal, or as definitive therapy. Two cases of central haemangiomas of the maxilla are presented, both treated successfully by embolisation.

Hemangioendothelioma of the gingiva. Histopathologic and therapeutic considerations

The hemangioendothelioma is a benign neoplasm, rarely observed in the mouth. In the literature, reports on the treatment and on the therapeutic results are lacking. This type of gingival neoplasm was observed in a young adult male. It was located in the attached gingiva in the upper and in the lower jaw, covering almost the entire coronal part of the anterior teeth. An exhaustive internal and neurological examination revealed no associated general disease. The gingival biopsies displayed the typical characteristics of a hemangioendothelioma: proliferation of the blood vessels, with a reduced lumen surrounded by swollen endothelial cells. The treatment consisted of a meticulous mechanical plaque control, chlorhexidine rinses, gingivectomy procedures and a monthly professional prophylaxis. 3 years after the periodontal treatment, the gingival structures remained clinically healthy. In the biopsies, only a small amount of inflammatory cells could be detected. This report shows a case of benign gingival neoplasms of unknown etiology in which meticulous plaque control, combined with extensive gingivectomies and repeated professional prophylaxis may have prevented or, at least, retarded the recurrence of the lesion.

Hemangioma of the maxillary sinus

Hemangiomas of the maxillary sinus are rare. Hemangiomas of the maxillary sinus with an associated phlebolith have not been previously reported. Severe bleeding can occur upon surgical removal of hemangiomas.

Intratumoral ligation in the management of orofacial cavernous haemangiomas

After a short comment on the essential data concerning the pathology, clinical aspects and treatment of orofacial haemangiomas, the author presents his own method of treatment by intratumoral ligation. He describes the technical details by which interception of the blood supply to the haemangioma is achieved and also breakdown of the angiomatous mass into segments by the occlusion of vascular channels, thus completely interrupting the intratumoral blood flow. Obstruction of vascular lumina, endothelial atrophy, blood clot organization in the small diverticula between them and also subsequent fibrous hyperplasia which take the place of the vascular hyperplasia ensue. The method was used in 31 cases of cavernous haemangioma in different sites; the results, with follow-up periods of 1-8 years prove its efficacy.

Vascular malformation: report of a case with eight-year follow up

An interesting example of a vascular malformation of the mandible has been presented. Early diagnosis made conservative treatment possible. Although the lesion was small, a considerable amount of hemorrhage was encountered during surgery. Adequate treatment was provided with ligation of external carotid arteries bilaterally in conjunction with curettage and packing. After an eight-year follow up, there has been no clinical or radiographic evidence of recurrence.

Intramuscular hemangioma of the tongue

A case of intramuscular hemangioma of the tongue originally suspected to be an epidermoid or dermoid cyst was presented. The correct diagnosis was discovered during surgery, when uncontrollable bleeding and the results from a frozen section revealed the true nature of the lesion.

Kaposi's sarcoma in a 2-year-old child

A rare case of Kaposi's Sarcoma primarily originating in the oral cavity of a 2-year-old male child with subsequent metastatic spread to the lymph node is presented and the literature reviewed.

Cryosurgical removal of a large oral hemangioma

Hemangiomas can present difficult management problems to the oral and maxillofacial surgeon when their removal is indicated. This article outlines total resolution of a large hemangioma with cryosurgery. The technique is simple to use, requiring a single treatment with minimal morbidity and patient discomfort.

Benign lingual lesions of intrinsic origin. Differential diagnosis

The tongue is the site of origin of a variety of reactive, neoplastic, and developmental swellings that all share a benign pattern of growth. They are significant because they can interfere with function, they can be mistaken for malignancy, or they can represent part of a syndrome. Distinctive clinicopathologic features of each are useful in differential diagnosis.

Arteriovenous fistula of the mandible: a review of the literature and report of a case

The authors, after a careful review of the literature during the last 15 years concerning arteriovenous malformation (AVM) of the jaws, report a case of congenital arteriovenous fistula of the mandible characterized by several episodes of spontaneous hemorrhage requiring emergency hemimandibulectomy. Radiologic, arteriographic and pathologic aspects of this lesion are discussed. Even though nomenclature concerning AVM of the jaws is confusing the authors draw attention to the embryologic features which are responsible for these lesions. They also point out the main diagnostic and therapeutic aspects emphasizing the small effect that ligation of the external carotid artery has on bleeding and the importance of choosing case by case the best treatment considering the great variety of clinical and pathologic aspects that characterize these lesions.

Mandibulo-facial aspects of the cervical cystic lymphangioma (cystic hygroma)

Sixteen cases of cervical cystic lymphangioma are reported; all but two were present at birth. Intra-oral extensions were detected in five and three of these caused macroglossia resulting in partial respiratory obstruction. Mal-development of the jaws and consequent dental malocclusion is a possible complication of the condition. In planning the treatment of such patients, maxillo-facial surgeons and orthodontists should be consulted at an early stage. The treatment of choice is complete excision, but where vital structures are involved repeated sub-total excisions are advocated.

Adult invasive subcutaneous hemangioma

Hemangiomas consist of a spectrum of benign vascular tumors with variable clinical behavior and microscopic morphology, which usually occur in infancy. A rare variant of these tumors is the invasive subcutaneous hemangioma, which shows an aggressive growth pattern by invading subcutaneous structures and recurring after apparent excision. The authors describe an adult patient with a large submandibular invasive hemangioma who was treated by preoperative embolization and surgical excision.

Arteriovenous malformation of the mandible

A recent case of a vascular malvormation involving the mandible prompted the review of this subject. There are less than 80 cases of this rare but serious disease reported in the literature. There is no accepted standard treatment, but recent contributions have improved the safety and effectiveness of therapy.

Central hemangioma of the maxilla

A case of central maxillary hemangioma is reported in which the only clinical symptom was spontaneous, recurrent, gingival papillary bleeding between the maxillary left premolars. The radiographic findings were inconclusive. It is strongly recommended that in cases where this diagnosis is suspected, surgical intervention be carried out under optimal conditions in an operating theater under hypotensive general anesthesia and with an ample supply of whole blood available.