Endovascular management of massive venous bleeding in anterior lumbar spine surgery: a narrative review

Abstract

Background and Objective

Anterior lumbar spine surgery provides a viable efficacious alternative to traditional posterior approaches. Vascular complications are usually managed with simple open surgical techniques. Rarely, massive venous haemorrhage transpires after a venous injury which may be life-threatening. Advanced endovascular devices and techniques provide alternatives to open surgery for the management of massive venous injury (MVI). The majority of descriptions utilise covered stents which often need to be adapted to the emergent situation and the venous anatomy. We aimed to review the venous anatomy, available endovascular devices, and describe techniques used to manage an MVI encountered during anterior lumbar spine surgery, and propose a staged, systematic approach for its endovascular management. These techniques can be used instead of, or combined with open techniques.

Methods

A review of national databases (PubMed, Ovid Medline and Google Scholar) was performed using literature from 2000 to 2024 in English. Keywords included terms “anterior” and “lumbar” and “spine” and “haemorrhage” and “venous injury” and “vascular injury” and “damage control” and “endovascular” and “venous thromboembolism”. Studies that described the anatomy, incidence, endovascular surgical techniques, complications, clinical and radiological outcomes of anterior lumbar spine surgery were included.

Key Content and Findings

We reviewed the relevant anatomy, patient work-up, lists of useful available endovascular equipment and devices, the stages of management, specific endovascular strategies and techniques, and the post-operative management of the patient.

Conclusions

Endovascular surgery can deliver control and definitive management with lower blood loss, reduced physiological insult while preserving venous patency. It is more likely to permit the completion of the spinal procedure than open surgical repair. Expertise in endovascular techniques is mandatory for their deployment. The best outcome is only achieved with a team approach to the situation, with the recruitment of appropriately skilled personnel and equipment. Endovascular techniques should be included in contingency planning for MVI.

Introduction

Schoeff et al. stated “rescuing patients from ilio-caval injuries is the most challenging technical aspect associated with treating spinal patients” (1). It is fortunately rare but confronting when it occurs (2). We define and discuss the pathophysiology of massive venous injury (MVI) in anterior lumbar spine surgery (ALSS) and its open management in our companion article in this issue “Open management of massive venous bleeding in anterior lumbar spine surgery”.

The ‘endovascular revolution’ has progressed apace in the last decade allowing endovascular techniques to tackle these confronting injuries (3). In particular, the devices for endovascular aneurysm repair (EVAR) of aortic and iliac arterial aneurysms have aided in the treatment of MVI in ALSS.

We aimed to review the venous anatomy, available endovascular devices, and describe techniques to manage MVI encountered during ALSS, and propose a staged, systematic approach for its endovascular management. We present this article in accordance with the Narrative Review reporting checklist (available at https://jss.amegroups.com/article/view/10.21037/jss-25-8/rc).

Methods

A review of national databases (PubMed, Ovid Medline and Google Scholar) was performed using literature from 2000 to 2024 in English. Keywords included terms “anterior” and “lumbar” and “spine” and “haemorrhage” and “venous injury” and “vascular injury” and “damage control” and “endovascular” and “venous thromboembolism”. Studies that described the anatomy, incidence, endovascular surgical techniques, complications, clinical and radiological outcomes of ALSS were included (Table 1).

Table 1. The search strategy summary.

Items	Specification
Date of search	29/11/2024
Databases and other sources searched	PubMed, Ovid Medline and Google Scholar
Search terms used	“Anterior” and “lumbar” and “spine” and “haemorrhage” and “venous injury” and “vascular injury” and “damage control” and “endovascular” and “venous thromboembolism”
Timeframe	2000 to 2024
Inclusion criteria	Studies that aimed to describe the anatomy, incidence, endovascular surgical techniques, complications, clinical and radiological outcomes of anterior lumbar spine surgery were included
Selection process	One independent reviewer conducted title and abstract screening using an inclusion criteria. The full-text of all selected articles were screened for eligibility. The reference lists of included studies were also reviewed to identify additional articles. If agreement could not be reached between two writers, a third writer was consulted

We have undertaken a narrative review of the use of these endovascular techniques in massive venous haemorrhage. We discuss the pre-operative and contingency planning, anatomy, workup, timing, high risk cases, basics of endovascular devices, stages of management, disadvantages of endovascular treatment, and post-operative management. Spinal surgeons’ areas of expertise traditionally do not encompass endoluminal techniques, and as such we aimed to provide a description of the broad types of endovascular devices available including their main properties to facilitate understanding of the described techniques.

Preoperative and contingency planning

If an MVI occurs, ideally all modalities should be available for its management. The surgeons, operative staff and hospital need to be appropriately equipped and capable of employing endovascular techniques. Contingency plans for the event of an MVI should have been formulated to ensure that requisite staff and equipment are available. A vascular surgeon (or interventional radiologist) is usually required to deploy endovascular devices and would be urgently consulted in the event of an MVI, if not already present.

Endovascular treatment is reliant on imaging technology—at least an image intensifier (I.I.) with digital subtraction angiography (DSA) capabilities (not all are equipped with this). Ideally the spinal procedures are performed in a hybrid operating theatre with angiography capabilities. An ultrasound machine with a 7 MHz probe and sterile cover should be available. A cache of the minimum required basic equipment should be maintained for the eventuality of an MVI (4) (Table 2).

Table 2. Endovascular equipment—suggested list to be maintained in case of MVI.

Insufflator [e.g., Sphere® Cook (Cook Medical), Encore 26® Boston (Boston Scientific)]

Sheaths [Micro kit: e.g., Micropuncture® Vascular Access Sheath Cook® (Cook Medical), 8–14 Fr (12 and 30 cm long) & 20 Fr Sheath (30 cm long)]

Guidewires [standard, stiff and extra stiff: 180 cm and 240 cm lengths; e.g., Glidewire®, Stiff Glidewire® 180 and 240 mm long (Terumo), Amplatz® 180 cm long (Boston Scientific), Lunderquist® (Cook Medical)]

Catheters [angled and straight end hole catheter; side hole imaging catheter—e.g., Omniflush® (Angiodynamicsm Latham)]

Balloons

• Compliant balloon [e.g., CODA® 32 and 46 mm Cook ® (Cook Medical)]

• Non-compliant balloon (diameter range, 10–18 mm, length range, 2–8 cm; multiple manufacturers cover some of the range)

Uncovered stents

• Balloon-expandable (diameter range, 7–16 mm, length range, 2–8 cm; multiple manufacturers cover some of the range)

• Self expanding (diameter: 10–20 mm, length: 40–120 mm long), e.g., Venovo® (DB International), Vici®, (Boston Scientific), Zilver Vena Venous® (Cook Medical), Abre® (Medtronic), Sinus Venous® (optimed Medizinische Instrumente GmbH)

Balloon expandable covered stents [diameter: 10–20 mm, length: 40–120 mm long. n.b. may be dilated beyond nominal diameter to variable degree (consult manufacturer)], e.g., BeGraft®/Be Graft Aortic® (Bentley), Viabahn ® VBX (Gore Medical) ↑ 11 mm; Lifestream® BD (Franklin Lakes) ↑12 mm, Advanta V12® Getinge, (Gothenburg) ↑12 mm

Self-expanding covered stents (diameter range, 12–20 mm, length range, 4.0–10.0 cm). Multiple manufacturers cover smaller diameters, e.g., Gore Viabahn® (Gore Medical) 5–13 mm diameter, 2.5–25 cm, 6–10 Fr sheath; BD Fluency® (BD International) 6–13.5 mm, 4.0–12.0 cm long

EVAR self-expanding stent-graft components

• Thoracic components (distal diameter range, 20–30 mm, length range, 8–15 cm), e.g., TAG® (Gore Medical) 21–31 mm diameter, 10 and 15 cm long; Zenith Alpha® (Cook Medical) 24–32 mm diameter 10 & 15 cm length

• Iliac stent-graft limbs with 16 mm proximal diameter (distal diameter range, 10–20 mm, length range, 8–15 cm), e.g., Excluder® iliac limb endograft (Gore Medical) 12–20 mm distal diameter, 10 and 14 cm lengths

• Medtronic Endurant II® limb (Medtronic) 10–20 mm distal diameter, 8.2, 12.4, and 14.6 cm lengths

↑, increases from. MVI, massive venous injury.

A vascular surgeon would be called in the event of an MVI, but the spinal surgeon, scrub and scout nurses and radiographer should have an understanding of the endovascular equipment and their possible roles in deploying it.

The possibility of an MVI should be accommodated when the patient is positioned, prepped and draped by ensuring that bilateral groins are included in the prepped field to allow prompt access. This is particularly true in cases at higher risk for venous injury. The operating table should be configured so that the I.I. is not impeded, and able to transition between anteroposterior and lateral views, and the intervening angles.

Anatomy and vein diameters

The anatomy, including abdominal and pelvic venous variations, has also been discussed in our companion open article.

When deploying balloons and stents in the veins, circumferential contact with the wall is required to achieve a seal and subsequent haemostasis. Oversizing of the stent by 10–20% is usual to ensure a seal with the vein wall and prevent stent migration. Under-sizing of a balloon or stent may not achieve haemostasis due to failure to seal, and risks stent migration. However, substantial oversizing can rupture the vein. Unfortunately, the sizing of veins with venography, particularly in the setting of injury and bleeding, is inaccurate and difficult. A rough guide to the size of the vein is therefore helpful.

The iliac veins are larger than their arterial counterparts. The common iliac artery and veins commonly have a diameter of 7–10 and 14–16 mm, respectively (5). Several authors report that the average diameter of the abdominal inferior vena cava (IVC) is 20–24 mm (average 22 mm), the common iliac veins (CIV) are 14–16 mm in diameter and the external iliac vein (EIV) is 12–14 mm (5-7). Venography is a relatively poor tool for sizing the vein diameter, but it will demonstrate a markedly dilated or stenotic vein allowing device sizing adjustment. If necessary, start with a smaller balloon diameter and sequentially increase it for more accurate sizing before definitive balloon and stent deployment.

Workup

The workup required for ALSS is covered in our companion open article. The presence of arterial and venous anomalies (e.g., dual IVC, left sided IVC, multiple renal vessels, atresia of the major veins, other pelvic venous variations) which would affect the endovascular management of an MVI should be noted (4,8).

Timing of utilization of endovascular techniques

Several authors now advocate using endovascular techniques as first line in the event of an MVI rather than attempting an open repair first (1,3,5,9,10). This is particularly true when unexpected scarring or radiotherapy change is encountered. After the initial manual pressure and resuscitation, if endovascular management is chosen, the appropriate staff and equipment should be assembled promptly.

High risk cases

In cases deemed to be at high risk of significant venous injury, a vascular surgeon should be recruited to the surgical team. They should consider the pre-emptive placement of small unilateral or bilateral common femoral vein access sheaths (e.g., 4 Fr) (4,5). These can be placed under ultrasound guidance without the pressure inherent in an emergent complication. This would allow for rapid upsizing to a larger sheath before endovascular control and management of a venous injury. If not required, there is little morbidity from pre-emptively placing small femoral venous sheaths, especially under ultrasound guidance.

Basic information about endovascular devices

Tables 3,4 provide basic information on some of the types of endovascular devices available. Balloons are available in various diameters and lengths, and are either complaint or non-compliant (Table 3). Stents are either self-expanding or balloon-expandable and can be either bare metal or covered (Table 4) (5).

Table 3. Endovascular devices: balloons.

Compliant	Non-compliant	Considerations
• Inflation is volume dependent • Continues to expand as inflated (until balloon rupture)· • Changes shape and size as inflated, conforming to vessel anatomy, allowing occlusion of the vessel • Inflated manually with 10–30 mL syringe (depending on balloon size) allowing tactile feedback to help avoid excessive pressure exertion	• Inflation is pressure dependent • Fixed maximum diameter—minimal increase in size beyond this with further inflation (until balloon rupture) • More commonly available • Inflation with insufflator to ensure excessive pressure (e.g., >4 atm) is avoided	• Balloons should be inflated under I.I. vision, ideally with a ‘road map’ of the vessel • Dilute contrast is used as the balloon inflation fluid • Non-compliant balloons should be inflated with an insufflator for accurate pressure control • The minimum pressure required for adequate inflation should be used in the venous system

I.I., image intensifier.

Table 4. Endovascular devices: stents.

Self-expanding	Balloon-expandable	Bare metal stents	Covered stents	Considerations
• Manufactured in a set diameter cylindrical forms from alloys with spring-like properties • Restrained inside a sheath • Sheath withdrawn to deploy once stent positioned • Less radial force but more flexible than balloon-expandable stents • If compressed by an external force, will deform but return to predetermined shape after force removed • They may require a larger sheath size	• Manufactured in a range of sizes • Crimped onto an appropriately sized balloon • Deployed as the balloon inflated • Sized to ensure contact with the vessel wall • Higher outward radial force but less flexible than self-expanding stents • If compressed by an external force, will deform and NOT return to previous shape after force removed (i.e., can be crushed) • Can often be over-dilated to some degree unlike self-expanding stents [e.g., from 10 to 14 mm for the Aortic BeGraft® (Bentley)]	• No covering over the stent struts • Blood can pass between the stent struts—the stent cannot directly exclude an injury from the circulation. If there is a deficit in the vein wall the stent alone will not seal the vessel • Haemostasis mechanisms: - Correction of a more proximal stenosis - Provides a scaffold for packing and balloon deployment	• Stent struts are covered by an impervious outer covering layer [e.g., polytetrafluoroethylene (PTFE)] • Blood is contained by the impervious outer covering • If the stent is sealed in an intact vein proximal and distal to an injury, the injury is excluded from the circulation arresting haemorrhage • Usually require a larger deployment sheath than bare metal stents	• Compared to veins, arteries have smaller diameter and higher intra-luminal pressure • Many of the commonly available stents are of an insufficient diameter for venous applications • Stents designed for the more proximal arterial tree may be required in emergency deployment in the abdominal and pelvic veins

An inflation device (insufflator) allows accurate control of the inflation pressure and volume.

Stents are commonly used to treat stenotic arterial lesions. Arteries have a smaller diameter but higher intra-luminal pressure than veins. Venous stent deployment is relatively uncommon, and as such the diameters of the stents kept in a hospital’s inventory are often insufficient for the venous system.

There are reports of successful haemostasis achieved using bare metal stents, including after venous injury in ALSS cases (1,11). Bare metal stents achieve haemostasis through two mechanisms: (I) the stent corrects a more proximal stenosis, relieving venous hypertension and providing a ‘path of least resistance’ into the IVC allowing the blood to remain intravascularly in the venous system; and (II) the stent provides a scaffold against which packing and haemostatic agents can be applied, and within which a balloon may be inflated to allow coagulation to occur (5). Shoeff et al. caution against using bare metal stents when there has been greater than 500 mL of blood loss due to risk of associated coagulopathy and failure (1,5). Balloon-expandable bare metal stents may also be deployed to correct a stenosis within covered self-expanding stents placed after an MVI, to prevent thrombosis.

Covered stents have been successfully used for MVI during ALSS (1). There are few dedicated venous covered stents, and the covered stent diameters immediately available are often too small for MVI cases. If there is a covered stent of the necessary diameter available, this can be used to address a venous injury. However, as available covered stents are often undersized, the reports in the literature are predominantly of self-expanding covered stent-graft components from aortic endovascular systems.

Stent post deployment dilation

Stents deployed in the arterial system are routinely post-dilated after deployment to ensure a good seal with the arterial wall. Authors caution against this practice in the venous system, both because of the risk of tearing the vein wall, and because the low venous pressure means it is not necessary (9).

EVAR stent-graft components

Aortic endograft components have proven invaluable in the management of MVI because they are the required diameter for the iliac veins and/or IVC (10,12). There are reports of the ‘off-label’ use of single and multiple iliac and thoracic aortic components from EVAR endovascular systems to treat MVI in spinal surgery (1,9,10). The exact details of the EVAR components used are not always specified in the reports, however, aortic endograft iliac limbs and thoracic components should be in the ‘emergency kit’ if an endovascular fix is to be contemplated (see Table 2).

The EVAR endovascular systems for aortic and iliac artery aneurysms are covered self-expanding stents (often referred to as stent-grafts), comprised of several components. They seal in the native vessel above and below the aneurysmal disease excluding it from the circulation. They are commonly not of a uniform diameter and have a more complicated configuration and deployment. If covered stents (self-expanding or balloon-expanding) of the correct dimensions are not available, EVAR stent-graft components can be used.

The EVAR systems usually have multiple components which dock and seal with each other as well as the native vessels. The devices for the thoracic aorta may be single or multiple cylindrical stent grafts (range, 22–44 mm diameter). The system for the abdominal aorta and iliac artery aneurysms is multi-component. This is comprised of a bifurcated main body for deployment in the infrarenal aorta, into which iliac stent-grafts limbs are docked and sealed, extending to and sealing in the iliac arteries below. The iliac limb components have a fixed proximal diameter determined by the manufacturer (e.g., 12 or 16 mm) to seal with the aortic main body component, but a range of distal diameters (10–27 mm) to seal in the iliac arteries.

It is important to understand the configuration of the component being used. They are designed to be introduced from femoral access. Some aortic components have an uncovered bare metal stent above the covered stent for fixation and stability. If the uncovered stent is deployed at the vein injury site, it will fail to seal the injury. Some stent-graft components have trigger wires which need to be released to completely deploy the stent-graft and allow removal of the introducer system. The labelled length of the iliac limb components does not commonly include the overlap length designed for docking with the abdominal stent graft component (e.g., Cook^®). The length and configuration of the entire stent graft component needs to be known to avoid maldeployment.

The proximal diameter of the iliac component is a fixed size designed to dock and seal into its bifurcated aortic main body counterpart. The proximal iliac limb diameter varies between manufacturers. Some iliac limb components have a proximal diameter of 16 mm [e.g., Gore Medical (Newark, DE, USA)], but others have a smaller proximal diameter of 12 mm [e.g., Cook Medical (Bloomington, IN, USA)]. The proximal stent graft diameter is important when used ‘off label’ to address a CIV injury. A 12-mm proximal diameter iliac limb deployed from ipsilateral femoral access will usually not seal the proximal CIV which typically has a diameter greater than this.

If the covered stent graft component extends from the CIV to the EIV it may be excessively oversized for the EIV and become crimped. This may be necessary due to a distal CIV injury, or due to limited lengths of available iliac limbs. This oversizing can cause a stenosis which may be severe enough to necessitate correction with a balloon-expandable bare metal stent of the appropriate diameter.

We recommend contacting the company representative for support if using an EVAR stent graft system to manage an MVI.

Stages of action in event of MVI and ALSS

The stages of management in the event of MVI have been previously discussed in our companion open article on open management. The progress through the stages is the same when endovascular management of MVI is used (see Figure 1). These broad stages are: initial manoeuvres, establish access and identify, control, and management.

Figure 1.

Endovascular management of a massive venous injury. CFV, common femoral vein; DSA, digital subtraction angiography; ICU, intensive care unit; IJV, internal jugular vein; IV, intravenous.

Initial manoeuvres

The initial manoeuvres employed when an MVI occurs are the same whether open or endovascular techniques are ultimately used and are covered in our companion open article.

Establish access and identify

After the patient has been resuscitated, the injury is inspected with a brief release of pressure which has been applied to the injured vessel during the initial manoeuvres. Attempts at open exposure, control and repair may result in further haemorrhage. A hostile environment due to radiotherapy or previous infection may have been encountered and pivotal in the causation of the injury. Open exposure and repair are more perilous in a hostile environment.

An endovascular approach can achieve haemostasis with less dissection and blood loss, and its resultant haemodynamic instability and sequelae. One of the benefits of the endovascular approach is that extensive exposure of the injured vessel is not required. If it is apparent that the site of the venous injury is not readily accessible or controllable using open techniques, an endovascular solution can be employed. This also applies if an open repair has proved futile.

Access

Establishing endovascular access is the crucial first step for an endovascular solution. Most authors advocate dual venous sheath access, usually bilateral common femoral venous sheaths. Occasionally, a common femoral vein (usually left) combined with an internal jugular venous sheath is necessary (1,9,10). An internal jugular venous access is not in the usual sterile field, and disturbing the anaesthetic field during a resuscitation should be avoided whenever possible. However some devices, due to their configuration, require deployment from a jugular access in order to achieve a seal and haemostasis (e.g., proximal stent diameter of only 12 mm) (1,9,10).

We advocate the use of a sterile ultrasound probe, initially with small sheaths [e.g., Micropuncture^® Vascular Access Sheath (Cook Medical)]. Care must be taken not to inadvertently injure a common femoral artery while establishing the venous sheaths, especially in a hypotensive patient. Inadvertent cannulation or injury of the femoral artery is the principal concern.

Once established, the access sheaths should be protected against inadvertent dislodgement by securing them to the skin with a suture to ensure venous access is not lost. Upsizing of the initial venous sheath may be required and is best performed over robust wires [e.g., Stiff Glidewire^® (Terumo, Tokyo, Japan) or Amplatz^® (Boston Scientific, Marlborough, MA, USA) under direct I.I. guidance (1).

We recommend advancing bilateral guidewires (e.g., Glidewire^®) beyond the lesion, well into the IVC, under I.I. guidance after the sheaths are established (10). This guards against inadvertent displacement or dislocation. The wires should be covered when not in use (e.g., with a drape). The early placement of bilateral iliac venous guidewires speeds the introduction and deployment of devices for control and management of the venous injury and provides more options to rescue the situation. The wires can be exchanged for stiffer wires [e.g., Stiff Glidewire^®, Amplatz^® or Lundequist (Cook Medical)] through a catheter as required (e.g., before the introduction of larger balloons, stents or stent-graft components). Brief relaxation of the manual compression may be required to allow the initial passage of the guidewire.

Identification of the injury

Identification of the venous injury site with venography can be challenging, even with DSA (9). The retractor blades and prosthesis may obscure the view, the bleeding may be slowed/hidden by manual compression, packing, or venospasm of the injured vein. The venography runs should be coordinated with the anaesthetic team and synchronized with a momentary cessation of breathing. Relaxation of the pressure over the injury site may be required unless torrential bleeding precludes this. Vasospasm may indicate the area of injury (11).

There are several manoeuvres which may help identify the site of venous injury (Table 5) (10).

Table 5. Manoeuvres to help identify the site of venous injury.

• Simultaneous bilateral femoral sheath injection rather than unilateral

• The placement of a side hole imaging catheter [over a wire, e.g., Omniflush® (B. Braun)] at the approximate level of the injury combined with a contrast pump

• Images acquired using different angles

Even so, the site of injury may be indicated only by an irregularity in the luminal outline of the vein. Bonasso et al. counsel against excessive efforts to precisely identify the bleeding site and rather recommend acting on the most likely source of bleeding (9). This is particularly true when the injured vessel has already been identified after direct inspection in the operative field.

Confirmation of successful treatment can be achieved with repeat DSA venography and direct inspection.

Control

Control of massive venous haemorrhage can be achieved with the deployment of a balloon under I.I. visualisation above, or across the lesion (1,9). It is preferable to deploy a balloon which is too small and upsize than to start with an oversized balloon and cause extension of the injury. Control can be confirmed by venography and/or direct inspection through the wound.

In cases where the exact location of the lesion is initially unknown, balloon inflation combined with packing and pressure can achieve haemostasis. Schoeff et al. reported using a 25-mm compliant balloon [e.g., CODA^® (Cook Medical)] in the distal IVC above the lesion to slow the haemorrhage (1). For smaller injuries, balloon inflation across the injury combined with topical agents and compression alone may be sufficient to achieve haemostasis although this is unlikely to be sufficient in larger injuries. Larger balloons may require upsizing of the sheath to allow passage of the balloon (e.g., a 32-mm CODA^® balloon requires a 10-Fr sheath).

The initial use of a balloon to achieve control is not mandatory. Some reports in the literature utilized balloon control either across the CIV lesion, or in the IVC above the lesion. In others, when adequate control is achieved by packing and pressure, the authors progressed immediately to the deployment of a stent or stent-graft (9,10). If the required devices are available, and the haemorrhage is controlled with pressure, the deployment of a stent may be the initial endovascular intervention.

Management

Definitive endovascular control of an MVI in ALSS usually involves the deployment of a stent. Several authors report definitively managing an MVI by deploying an appropriately sized covered stent so that it seals in the vein above and below the injury, isolating the injury from the circulation. This can be combined with the application of topical haemostatic agents (1,9,10).

Different endovascular strategies are required depending on the location of the injury due to the venous anatomy, and the configuration of the devices. The required management is different for injuries involving: the CIV separate from the IVC; the confluence of the IVC; and the IVC above the confluence (Table 6).

Table 6. Endovascular management of venous injury by injury site.

Mid to distal CIV injury

• Bare metal stent, haemostatic agents and temporary pressure (smaller injuries, <500 mL bleed)

• Covered stent—balloon- or self-expanding (if appropriate diameter available)

• Aortic stent-graft iliac limb deployed over a stiff wire

- 16 mm proximal diameter—can be deployed from the femoral access

- 12 mm proximal diameter (e.g., Cook®)—requires internal jugular vein access deployment unless CIV small

• Stent may extend into the EIV if more distal CIV injury, or shorter device not available

Proximal CIV/confluence of the IVC

• Kissing iliac stents

• Exclusion of contralateral CIV

IVC injury separate to the confluence

• Kissing iliac stents

• Covered stent to IVC—risk of stent migration

• Open repair

CIV, common iliac vein; EIV, external iliac vein; IVC, inferior vena cava.

Injuries involving the CIV separate from the IVC confluence

There are several options for an injury of the CIV which has sufficient intact vein (>1 cm) between the injury and the IVC confluence. Balloon-expandable bare metal stents, balloon-expandable covered stents and self-expanding covered stents have all been described to treat these injuries (1,9,10).

Schoeff et al. treated 3 cases with bare metal stents, either alone or combined with prolonged balloon inflation (1). However, in one case a covered stent was also required to achieve haemostasis. If the total blood loss is less than 500 mL, a trial of an uncovered stent may be reasonable but Schoeff et al. caution against it with a more substantial haemorrhage due to the escalating risk of failure (1).

If an appropriately sized self- or balloon-expanding covered stent is available, this can be deployed across the injury. However, stents with the required diameter are often not immediately available.

The self-expanding iliac stent-graft limbs of EVAR systems are often more readily available and effective. An important consideration is the proximal diameter of the stent graft limb which varies between manufacturers. Iliac stent graft limbs with a 16-mm proximal diameter (e.g., Gore^®) are usually adequate to seal in the CIV. Bonasso et al. deployed a 16 mm iliac EVAR stent-graft limb from femoral access to successfully exclude a CIV injury (9).

Schoeff et al. deployed a Cook Zenith EVAR iliac stent-graft limb with a 13-mm proximal and 20 mm distal stent diameter to effectively treat a CIV injury (1). The proximal diameter of 13 mm would usually be inadequate to seal in the CIV. This required internal jugular vein (IJV) access to allow the graft to be deployed in an inverted fashion from its usual orientation allowing the 20 mm diameter section to be deployed and seal in the CIV, and the 13 mm diameter section in the EIV (1). If this iliac limb had been deployed from femoral access, it is unlikely to have sealed in the CIV due to its smaller 13 mm proximal diameter.

If there is a seal zone in the proximal CIV, but the injury extends to close to the CIV confluence, the covered stent will need to be extended into the EIV. This is also the case when there is no available stent/stent-graft short enough to allow its deployment to be confined to the CIV. The configuration of the EVAR stent-graft iliac limb components is an advantage when the distal seal needs to be in the EIV. In some patients, 16 mm is adequate to seal in the CIV, but a smaller diameter is required in the EIV. In this scenario, iliac limbs with a proximal diameter of 16 mm, and a range of distal diameters are helpful (e.g., Gore^® Excluder).

Ilio-caval confluence injuries

The commonly instrumented disc levels (L4/5 and L5/S1) are near the confluence of the IVC, and commonly reported MVI injuries occur in this area (9,10,13). Injuries at or near the ilio-caval confluence are some of the most difficult to treat, open or endovascularly. The haemorrhage from an injury in this area can come from either of the iliac veins and the IVC. A single tube graft cannot be deployed without excluding the outflow of one CIV. In addition, at the confluence of the IVC, there is a substantial calibre change between the IVC and CIVs.

Two broad techniques have been described in the literature to address ilio-caval confluence injuries: (I) kissing covered iliac stents; and (II) a covered stent deployed from the IVC into one CIV, excluding the contralateral CIV (9).

In reports of MVI in ALSS, kissing iliac vein stents have been the chosen management strategy, while extending a covered stent from the IVC to one CIV has been used as a bail-out procedure after the failure of an initial intervention (e.g., deployment of a covered stent confined to the CIV). In these reports, both described strategies utilised covered stents including the self-expanding EVAR stent-graft components (4,5,9,10,14,15).

The kissing iliac stent technique involves simultaneously deploying bilateral CIV EVAR iliac stent-graft components (of the appropriate lengths and diameters), with both extending equally 2–3 cm into the IVC proximally, and into their respective CIV distally.

Each iliac limb is introduced from femoral access. Proximally, they are contact with each other in the IVC (‘kissing’), conforming and sealing with the IVC wall and each other. This configuration preserves the outflow from both CIVs, while sealing the IVC above and the CIVs below. This excludes the injury from the circulation and achieves haemostasis (10,14). It is a more complex procedure, requiring secure bilateral femoral access, more resources, and two proceduralists to simultaneously deploy the iliac limbs.

The second strategy described is to deploy a stent-graft extending from the IVC to the injured CIV beyond the injury, sealing the injury from the circulation. It comes at the expense of excluding the uninjured contralateral CIV from the IVC and impairing its venous drainage. This can be an effective treatment for an IVC or CIV injury near the confluence. However, if the injury is at the confluence and communicates with the excluded contralateral CIV, the injury will not be excluded allowing haemorrhage to continue.

There are no covered stents of an adequate and appropriate diameter for both the IVC and the CIV. The reported cases of endovascular treatment of MVI during ALSS using this technique employed a smaller thoracic aortic EVAR component (e.g., 26 mm) to bridge between the IVC and the iliac vein. A thoracic endograft is a reasonable diameter for the IVC but is significantly oversized for the CIV, which can cause bunching of the stent within the iliac vein and a stenosis. A significant stenosis will need to be corrected with a balloon-expandable stent to prevent sudden venous thrombosis.

Bonasso et al. described two cases treated endovascularly with this latter technique. Initially, a unilateral EVAR iliac stent-graft limb was deployed in the CIV but failed to arrest the haemorrhage due to the proximal location of the CIV injury (9). A thoracic aortic EVAR endograft stent-graft (26 mm diameter) was subsequently deployed extending from the IVC into a CIV as a ‘rescue’ procedure to arrest the haemorrhage at the expense of unilateral CIV exclusion. In one case, the thoracic endograft was deployed from the IVC into the previously placed EVAR iliac limb which had been deployed in the injured ipsilateral CIV. In the second case, an EVAR iliac limb had been deployed in the CIV for an injury which extended to confluence and continued to bleed, necessitating the deployment of an EVAR thoracic aortic component from the IVC to the contra-lateral CIV to exclude the injury (9).

We would caution against treating proximal iliac and IVC confluence injuries with bare metal stents due to the complexity of interventions required, and the likely volume of haemorrhage. These are ‘high stakes’ injuries and if the bare stents fail to achieve haemostasis, further interventions will be limited by the presence of the bare stents, and even more complex.

IVC injury separate to the confluence

An injury to the IVC more than 2–3 cm proximal to the bifurcation could be treated with a covered stent, provided it is sufficiently short and will not occlude the renal vein/s. To our knowledge, there are no reports of this strategy being used for MVI in ALSS. Most of the thoracic EVAR components are 7 cm or longer and are likely to be too long for this indication. There are balloon-expandable covered stent grafts available which are shorter with the required diameter [e.g., BeGraft Aortic^® (Bentley, Bentley InnoMed GmbH, Hechingen)]. However, the authors have no experience using these shorter covered stents emergently for an IVC injury. We feel that their use would carry a risk of migration of the stent proximally across the renal or hepatic veins, or more centrally. Therefore, we would recommend the ‘kissing’ EVAR iliac stent-graft component technique extending further into the IVC, or open repair in this rare circumstance.

Access sheath management

The venous sheaths can usually be removed with a period (5–15 minutes) of direct manual compression of the puncture site. Large sheaths (e.g., 22 Fr) may need formal repair of the common femoral vein. In patients who are markedly coagulopathic, moderately sized sheaths (e.g., 10 Fr) should be left in situ until the coagulopathy has been corrected.

Hybrid management

The management of MVI in ALSS does not need to be purely open or endovascular. The open surgical techniques are discussed in our companion open article. A combination of open and endovascular surgery may provide a successful resolution with less haemorrhage and resultant physiological impact. For example, endovascular venous control and management may be accompanied by open distal aortic cross clamping. A stent deployed across the lesion can be accompanied by the application of topical agents and temporary pressure to achieve haemostasis. An initial attempt at open surgery may be met with excessive bleeding, and a change to endovascular techniques may be made (Figure 2).

Figure 2.

Open and endovascular management of massive venous injury. CFV, common femoral vein; DSA, digital subtraction angiography; ICU, intensive care unit; IJV, internal jugular vein; IV, intravenous.

Significant haemorrhage after MVI with its sequelae may still warrant a damage control surgery even after successful endovascular management, and this has been described in several reports (1,9).

Abandonment of the spine procedure

In cases of MVI in ALSS, the injury to the vein often occurs during exposure or preparation of the disc space, before implantation of the prosthesis. Completion of the spinal procedure after MVI is not mandatory, and future surgery through an alternative approach (e.g., lateral or posterior) is usually possible. Even after successful endovascular management of the venous injury, the patient may be haemodynamically unstable, physiologically impaired and coagulopathic, in which case continuing with the spinal surgery is contra-indicated (1,9,16).

Cases of successful completion of the spinal procedure after endovascular management of a venous injury have been reported (1,10). However, continuing with the spinal procedure may entail manipulation of the veins and the endovascular device, risking deformation of the endovascular devices, disturbance of the seal and recurrence of the bleeding. Further endovascular interventions are often limited in this scenario.

Disadvantages of endovascular management of MVI in ALSS

Vascular surgeons are well acquainted with the devices and techniques described but spinal surgeons have limited knowledge. This may also be true of the spinal operating room staff and surgical assistant. If a vascular surgeon (or similarly skilled proceduralist) is not available, then an endovascular solution is not possible.

Endovascular techniques require a substantial range of devices to be rapidly available. This may not always be the case, even in larger institutions. Ideally a range of endovascular equipment would be kept specifically to allow endovascular management of MVI in ALSS. The I.I. should be capable of DSA, but this is not always the case.

The reports in the literature commonly utilize devices outside of their instructions for use due to the emergency nature of MVI. As such these devices are being used ‘off-label’, and some aspects of their configuration require compromise from the ideal, and adjustments to their deployment.

Post operative management

Injured veins have an increased propensity for thrombosis post operatively, irrespective of the repair method used (5,17). This is higher if there is prosthetic material placed in the vein (18). Chemoprophylaxis post operatively was also discussed in our companion open article.

Compression hosiery and sequential mechanical compression devices should be employed post-operatively unless contra-indicated (19). The evidence is limited regarding chemoprophylaxis after anterior spinal surgery, especially non-elective surgery (19). We recommend chemoprophylaxis after endovascular treatment of MVI as soon as it is safe to use. It should continue at least until the patient is fully ambulant. Schoeff et al. fully anticoagulated 3/4 of their patients long-term including one after an episode of stent thrombosis (1). Frank et al. reported that the incidence of deep vein thrombosis (DVT) after open repair rises by 28% for each day without chemoprophylaxis (17). We recommend transitioning to full anticoagulation for 6 months if safe after venous stent implantation.

Conclusions

MVI in ALSS is a rare but a potentially lethal complication.

The evolution of advanced endovascular technology provides a potent treatment alternative to traditional open repair for the management of an MVI. There are scant devices of the necessary size specifically designed for use in the venous system. Most of the devices described in the literature used in cases of MVI are EVAR stent-graft system components originally designed for the treatment of aorto-iliac arterial aneurysms. Their configuration and deployment are more complicated.

The best outcome after an MVI during ALSS may be achieved using endovascular over open techniques. Endovascular surgery can deliver control and definitive management with less blood loss, reduced physiological insult and maintenance of venous patency. They are more likely to permit the completion of the spinal procedure than open surgical repair in select cases. The endovascular devices often need to be adapted from their principal purpose, and expertise is mandatory for their deployment. The spine and access surgeon should be aware of the devices and endovascular techniques, and these should be included in contingency planning for an MVI. Endovascular and open surgical techniques may be combined.

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Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.