Endovascular Aortic Balloon Occlusion in Obstetrics
Karin A. Fox
Laura J. Moore
Postpartum hemorrhage is a leading preventable cause of maternal morbidity and mortality worldwide.
In cases of massive extremity trauma, compression with tourniquets is possible to limit and control bleeding.
The major vessels of the abdomen and pelvis, including the common femoral arteries, iliac arteries, and aorta, are generally noncompressible using external maneuvers.
Traditionally, hemorrhage owing to catastrophic abdominopelvic trauma required immediate laparotomy and open surgical vascular control.
Advances in trauma care have led to the development of endovascular techniques to control hemorrhage within the abdomen and pelvis, specifically endovascular balloon occlusion of the aorta, to temporize bleeding while maintaining perfusion of the heart and brain while achieving surgical hemostasis.
The goal of endovascular balloon occlusion of the aorta is to temporize hemorrhage as a bridge to definitive surgical management not to replace open surgery.
Early vascular (i.e., common femoral arterial) access and early multidisciplinary care are recommended when using this technique.
The multidisciplinary team and trained endovascular trauma team may consist of general or trauma surgeons, vascular surgeons, interventional radiologists, and emergency medicine physicians.
Between 500 and 700 mL of blood flows through the uterus at term; therefore, rapid exsanguination is possible if hemostatic control cannot be obtained with usual measures.
Management of obstetrical hemorrhage has borrowed heavily from battlefield and trauma resuscitation techniques, with regard to the adoption of use of massive transfusion protocols, balanced blood product ratios, and the use of tranexamic acid.
Traditional vascular surgical techniques that have been employed in extremis in cases of obstetrical and gynecologic hemorrhage include sequential vascular ligation (including hypogastric artery ligation) and aortic cross-clamping cephalad to the level of the bifurcation of the aorta and caudal to the renal arteries (1).
Occlusion of the iliac arteries has proven to be less effective than originally reported in reducing blood loss in the setting of massive hemorrhage (as with placenta percreta). This is most likely owing to the massive collateral flow to the uterus from vessels that originate from vessels even more cephalad than the uterine arteries (2,3,4).
Resuscitative endovascular balloon occlusion of the aorta is a technique that is being increasingly used and investigated in the setting of obstetrical hemorrhage, especially in the most difficult to manage cases such as in the management of the placenta accreta spectrum or catastrophic disseminated intravascular coagulopathy.
In most cases in obstetrics to date, use has been limited to preplanned placement of the femoral artery sheath and/or balloon catheter for anticipated complex surgical cases such as placenta accreta spectrum.
Different brands and sizes of catheters are available for use. Surgeons planning to employ aortic balloon occlusion should be familiar with the technical details of use specific to the catheter and equipment they employ.
The aortic balloon catheter is placed in zone 1 (thoracic aorta at the level of diaphragm) for major intra-abdominal or retroperitoneal hemorrhage, but for pelvic bleeding (and obstetrical hemorrhage), placement in zone 3 below the renal arteries and above the bifurcation of the aorta is most appropriate (Figure 6.7.1).
Use in overt, massive hemorrhage is considered an emergent, salvage technique and may both be more technically difficult when the patient is hemodynamically unstable.
Ongoing research is needed to further understand the full range of benefits, risks, complications, and patient selection for use of aortic balloon occlusion in obstetrics; however, in experienced hands, early studies indicate the potential for a significant reduction in bleeding and transfusion requirements (5,6,7).
Methods to control bleeding may prove useful especially in patients who refuse transfusion or for whom sufficient type and cross-matched blood for transfusion is otherwise unavailable.
Team and individual training is available and recommended through courses such as the Basic Endovascular Skills in Trauma (BESTTM) Course (8).
Aortic balloon occlusion is contraindicated in patients with an allergy to contrast media, who do not have femoral artery access that can accommodate the arterial sheath required (range 4F-12F sheath depending upon the device used), minors (under age 18), or in patients with an aortic diameter >32 mm.
The aortic balloon can be deflated and reinflated (provided the positioning remains stable). Total inflation time should be minimized and should not exceed 60 minutes in zone 3 (Figure 6.7.1).
Identify appropriate external anatomical landmarks to access the femoral artery. The femoral artery is located in the femoral triangle, which is bordered superiorly by the inguinal ligament, medially by the adductor longus muscle, and laterally by the sartorius muscle.
Inguinal ligament (which runs from the anterior superior iliac spine to superolateral pubic tubercle): The common femoral artery (CFA) is 2 cm below the inguinal ligament (Figure 6.7.2).
In obese patients, consider cephalad retraction of the pannus by an assistant to facilitate the identification of external landmarks. It is important to identify the bony landmarks to properly locate the inguinal ligament, as the inguinal skin folds will not provide accurate localization of the CFA.
Some balloon catheters designed specifically for aortic occlusion have centimeter marks, and on average, placement of the catheter is around 28 cm for zone 3 placement (tip of the catheter to the xyphoid process or balloon placed at the level of the umbilicus).
Ultrasound guidance for identification and verification of access within the femoral artery is the standard of care. Caution should be used in arteries that have extensive plaque formation or calcifications.
IMAGING AND OTHER DIAGNOSTICS
Ultrasound guidance is the standard during access to the femoral artery.
Once the approximate location of the CFA is identified, ultrasound can be used to confirm the location and visualize needle-guided access and catheter placement.
Ultrasound may also be used post removal of the catheter and sheath to assess the integrity of the arterial wall or for signs of thrombus formation. A routine vascular ultrasound of the access site in the CFA is recommended 48 hours after sheath removal to evaluate for pseudoaneurysm formation.
Balloon placement may be confirmed by direct palpation of the balloon, using an x-ray or a portable C-arm and fluoroscopy.
Ensure appropriate team members and protocol available, including vascular/trauma surgeons or interventional radiologists.
Assemble and prepare equipment including:
Ultrasound machine with linear or curvilinear transducer
Appropriately sized arterial sheath (for the type of balloon used) with introducer needle
Aortic balloon catheter of choice
Arterial line tubing and transducer for monitoring
Crystalloid for intravenous infusion
Intravenous normal saline
Local anesthetic (1% lidocaine) and needle
Scalpel (11-blade recommended)
Suture to secure the vascular sheath
Clear surgical film dressing (i.e., OPSITE or TegadermTM)
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