Fig. 3.1
Lateral skull radiograph in an infant
Figure 3.1 represents an example of a/an
- (a)
Cephalohematoma
- (b)
Subgaleal hematoma
- (c)
Epidural hematoma
- (d)
Caput succedaneum
Answer: (b) Subgaleal hematoma
Introduction
Scalp and skull injuries account for nearly two-thirds of all birth traumas [1]. Most of these minor injuries can be treated conservatively; however, early identification of those complications that may require surgical intervention is critical. When evaluating patients during visits in the first week or while still in the nursery, it is important to remember that the greatest risk factor for skull or scalp trauma is instrumented delivery with forceps or vacuum devices. Macrosomia and primiparous mothers are other risk factors for injury to the newborn skull during delivery. These injuries can be grouped into three categories: extracranial hematoma, intracranial hematomas, and skull fractures without hemorrhage. Surgical intervention is predicated on the severity of the trauma and potential for worsening or neurologic injury.
Extracranial (Scalp) Hematoma
To understand extracranial hematomas , it is important to review the layers of the scalp. From superficial to deep, the layers of the scalp include the skin, dense subcutaneous tissue, galea aponeurosis, loose subaponeurotic (connective) tissue, and the pericranium (also referred to as periosteum) (Fig. 3.2). Venous drainage from the scalp is primarily through emissary veins that traverse the skull and drain into the intracranial dural venous sinuses. Likewise, diploic veins drain the diploic space, which is the area of cancellous bone between the outer and inner tables of the skull.
Fig. 3.2
Anatomic layers between the brain and the skull define specific injury planes
Infants with scalp hemorrhages typically present with focal swelling, abnormally enlarging head circumference, anemia, indirect hyperbilirubinemia, and in severe cases, hypotension secondary to severe intravascular volume loss. A 50 cc hematoma can represent a significant portion of the intravascular volume of a normal 3.5 kg newborn. Plain films or noncontrast computed tomography (CT) scans of the skull can be obtained to exclude an underlying skull fracture and intracranial hematoma. Certainly in the hospital setting, signs such as a full fontanel or lethargic behavior such as failure to feed will prompt an urgent imaging evaluation; however, in the office setting, a well-appearing baby with a scalp swelling might very justifiably be managed with observation alone. Extracranial hematomas are generally treated conservatively with volume resuscitation, blood transfusions, phototherapy, and observation.
Caput Succedaneum
Caput succedaneum refers to a hematoma that forms beneath the subcutaneous tissue and above the galea (Fig. 3.2). These collections are not considered pathologic in all cases, as most occur spontaneously to a mild degree during normal vaginal delivery. During birth, pressure around the presenting part of the scalp against the cervix prevents venous drainage from that area. In this regard, prolonged vaginal and vacuum-assisted deliveries are the biggest risk factors for developing caput succedaneum. They are present immediately following birth and can have varying degrees of ecchymosis and associated skin color changes. The swelling usually has ill-defined margins, which cross cranial sutures. Management consists primarily of observation, as caput succedaneum often resolves within a few days [1] without any long-term neurologic or cosmetic sequelae following resolution .
Subgaleal Hemamtoma
The subgaleal space extends anteriorly from the orbital ridge to the nape of the neck posteriorly, and laterally to the ears (Fig. 3.2) [2]. Subgaleal hematoma s form in the potential space between the galea and the periosteum, therefore can cross suture lines. Rupture of the emissary veins caused by vacuum-assisted delivery is the most common cause, although they can also be seen with head trauma in young children beyond the infancy. Skin bruising and a boggy fluid collection can be noted on physical exam. The time frame for development is typically between 6 and 72 h after delivery. In addition to anemia and hyperbilirubinemia, hypovolemic shock can ensue as 50 % of a newborn’s blood volume can fill up this potential space [3]. These children should be screened for coagulopathies that need rapid and prompt correction. Management is primarily conservative, with observation, blood transfusion, and phototherapy as needed.
Cephalohematoma
Cephalohematomas, also referred to as subperiosteal hematomas, are scalp masses seen in infants following delivery, and are most commonly associated with vacuum-assisted deliveries [4]. The blood sources of these hematomas are the diploic veins of the skull which communicate superficially with veins in the periosteum. In this regard, hematomas form in the space between the periosteum and the outer table of the skull (Fig. 3.2). Given that the bleeding source is from the respective skull bone, these hematomas do not cross the cranial suture lines, distinguishing them from caput succedaneum and subgaleal hematoma s. Plain films and CT imaging may be obtained to rule out an underlying fracture. Aspiration of these collections is not advised due to the risk of infection, which has the potential to spread and result in osteomyelitis. As with other scalp hematomas, these collections are primarily observed clinically while correcting anemia and lab abnormalities. Imaging of these resolving collections (not routinely recommended) will reveal a calcification pattern that forms from the periphery to the center .
Intracranial Hematomas
Intracranial hematomas are exceedingly rare complications of birth trauma. However, such hematomas have the potential to cause rapid deterioration due to the small intravascular reserve of the newborn baby and fairly expansile intracranial space within which blood can asymptomatically collect, before presentation with hemodynamic collapse. While intracranial hemotomas can also present with scalp swelling or enlarging head circumference, they are more likely to present with acute neurologic deterioration or alteration in consciousness. Failure to recognize these hematomas early may lead to significant brain damage and ensuing herniation that can be fatal. It is paramount for neurosurgeons to be alerted early for the proper management of these hematomas and for them to assess the need for any intervention that may include drainage through a burr hole or a craniotomy for evacuation of hematoma.
Epidural hematomas (EDH ) (Fig. 3.3) occur between the inner table of the skull and the dura. They usually result from injury to the middle meningeal artery secondary to an overlying skull fracture. Given the pliability of the skull in infants, EDH can simulate the presentation of scalp swelling. While these hemorrhages are true emergencies, not all require surgical decompression. Spontaneous resolution of infant EDH has been seen as the blood products escape extracranially through the fracture, rather than compressing the underlying brain. These can still result in significant and rapid hemodynamic compromise.
