A simplified extracorporeal shunt configuration for temporary selective renal blood perfusion during open aortic surgery

Abstract

Acute kidney injury remains a relevant complication of open aortic surgery requiring suprarenal cross-clamping. We describe a simplified extracorporeal shunt configuration for temporary selective renal blood perfusion using devices routinely available in vascular operating rooms. Brachial arterial inflow is connected to a 9F Pruitt-Inahara shunt, whose limbs are positioned within the renal artery ostia. In our initial experience of five consecutive patients, technical success was achieved in all patients, with no postoperative deterioration in renal function or need for renal replacement therapy. This technique provides a practical and reproducible adjunct for select open aortic procedures.

Acute kidney injury is one of the most relevant complications after open aortic surgery requiring suprarenal or supravisceral aortic cross-clamping. Even transient postoperative renal dysfunction may prolong the hospital stay, increase morbidity, and negatively affect both early and late survival. The risk is particularly relevant in patients undergoing open repair for juxtarenal and pararenal abdominal aortic aneurysms and complex aortoiliac occlusive disease or receiving redo aortic reconstruction, in whom renal ischemia may be unavoidable during proximal control and anastomosis.^1,2

The renal ischemia duration is a key determinant of postoperative renal dysfunction. Although several studies have suggested that suprarenal clamping for up to 30 to 50 minutes may be well-tolerated in patients with normal baseline renal function, postoperative renal outcomes depend on multiple factors, including pre-existing chronic kidney disease, duration of ischemia, intraoperative hypotension, embolization, and technical complexity of proximal reconstruction. Therefore, renal protection strategies should be considered selectively rather than routinely, particularly in patients at increased risk of postoperative acute kidney injury.

Therefore, simple methods that can reduce the duration or severity of warm renal ischemia remain attractive adjuncts in select open aortic procedures.¹

Several renal protection strategies have been described. These include no adjunctive perfusion with the minimization of clamp time, cold crystalloid perfusion, cold renal perfusion with histidine-tryptophan-ketoglutarate or similar solutions, selective blood perfusion, temporary bypasses, and passive shunting techniques. Despite extensive clinical experience, no universally accepted strategy exists. Cold crystalloid perfusion is technically simple and widely used in many centers, but it requires renal ostial cannulation, preparation of perfusion fluid, and repeated administration during longer clamp intervals. Continuous blood perfusion may offer sustained oxygen delivery, but it generally requires a prepared inflow source, a dedicated circuit, or additional anastomoses.^1,2

Temporary extracorporeal shunting for visceral or renal perfusion is not a new concept. Historical reports have described radial renal artery shunting during complex aortic reconstruction, and more recent research has used passive temporary visceral shunts or endovascular shunting concepts during thoracoabdominal and complex aortic surgery. These techniques are physiologically appealing but may be limited by the need for specific devices, larger access sheaths, graft anastomoses, or additional operative preparation. In unexpected scenarios, a rapidly available solution assembled from standard operating room devices may be useful.^3,4

We describe a simplified extracorporeal shunt configuration for temporary selective renal blood perfusion during suprarenal aortic cross-clamping. This technique uses brachial arterial inflow, a 9F introducer sheath, a sterile extension line, and a 9F Pruitt-Inahara shunt. The purpose of this report is to present a practical and reproducible configuration of a type of extracorporeal renal shunt, to describe the operative steps, and to provide the results for the first five consecutive patients treated within an institutional prospective registry.

Technique description

The technique is intended for select open aortic procedures in which suprarenal cross-clamping is planned or becomes necessary and the surgeon anticipates a clamp duration long enough to justify temporary renal blood perfusion. Standard exposure of the abdominal and pararenal aorta is performed according to the underlying disease and operative plan. Before aortic cross-clamping, systemic heparinization is administered at 100 IU/kg, with a target activated clotting time between 200 and 300 seconds.

Arterial inflow is obtained through the surgical exposure of the right brachial artery, with the patient’s right arm maintained alongside the body, allowing simultaneous brachial access without interfering with the abdominal operative field. Clinical examination confirms palpable brachial, radial, and ulnar arteries pulses before brachial cannulation. Routine preoperative Allen testing or duplex assessment of the forearm arteries is not considered necessary because the cannulation is temporary without any clinical evidence of upper-extremity arterial disease.

After vessel control, a 9F introducer sheath is inserted retrogradely into the brachial artery and secured. The sheath is connected to a sterile extension line, approximately 20 cm in length and 4 mm in diameter; the sterile extension line is flushed with heparinized saline to eliminate air and reduce the risk of thrombosis.

The extension line is then connected to the T-port of a 9F Pruitt-Inahara carotid shunt (Pruitt F3 Carotid Shunt, LeMaitre Vascular, Inc.).

The Pruitt-Inahara shunt connected to a 20-cm extension line generally provides sufficient length in all patients, regardless of body habitus. If required, the extension line may be adjusted, although excessive tubing length should be avoided to minimize resistance and reduce the risk of kinking. The extension tubing should be kept as short as possible and positioned to avoid inadvertent traction that may result in shunt displacement during graft manipulation.

The extracorporeal circuit is therefore composed of a brachial arterial inflow sheath, a short sterile extension line, and a Pruitt-Inahara shunt used as the renal perfusion catheter, Fig 1, Fig 2, Fig 3.

Fig 1.

Schematic of the extracorporeal renal perfusion circuit. Brachial arterial inflow is connected to the Pruitt-Inahara shunt through a sterile extension line, facilitating temporary selective renal perfusion during suprarenal aortic clamping.

Fig 2.

Assembly of the extracorporeal renal perfusion circuit. A, Surgical exposure of the brachial artery with insertion of a 9F introducer sheath used for arterial inflow. B, Connection of the brachial sheath to the Pruitt-Inahara shunt through a sterile extension line.

Fig 3.

Configuration and intraoperative use of the Pruitt-Inahara shunt for selective renal perfusion. A, Components of the shunt, including the T-port, perfusion lumen, balloon inflation lumens, and independently inflatable balloons. B, Intraoperative selective renal perfusion with the shunt extremities positioned within the renal artery ostia.

The Pruitt-Inahara shunt is a multilumen device equipped with two independently inflatable balloons. In its conventional use, these balloons stabilize the shunt within arterial lumens. In the present configuration, the two terminal limbs are used for selective renal ostial cannulation. Before deployment, the circuit is flushed, and the balloon inflation lumens are tested. The entire circuit can be assembled in approximately 2 minutes once all components are available on the sterile field.

After suprarenal aortic cross-clamping and aortotomy, the renal artery ostia are identified. The two extremities of the Pruitt-Inahara shunt are inserted directly into the renal artery ostia. The white and blue balloons are then gently inflated with saline to obtain stable intraluminal fixation. Balloon inflation should be sufficient to secure the shunt and limit back-bleeding, but excessive inflation should be avoided to reduce the risk of ostial trauma. When stable positioning is confirmed, clamps on the circuit are released, and pulsatile blood flow from the brachial artery is allowed to perfuse both kidneys.

The system is passive and driven by the patient’s native arterial pressure. No external pump, dedicated perfusion console, or additional vascular anastomosis is required. In the initial cases, the estimated flow ranged between 100 and 200 mL/min per kidney, as also reported by Millinger et al⁵ with a similar bench condition with a 9F Pruitt-Inahara shunt and 30-cm tube line. This is lower than physiological renal blood flow. The technique should therefore be interpreted as partial continuous perfusion rather than providing the complete replacement of native renal circulation. Nevertheless, even low-flow oxygenated blood perfusion may provide metabolic support during kidney exposure to complete warm ischemia.⁴

With the shunt in place anterior and upper to the site of suture, aortic neck preparation and proximal anastomosis can be performed (Fig 3, B). The circuit should be kept visible and free of kinking throughout the period of perfusion. After completion of the proximal suture line, the aortic clamp is repositioned onto the graft, restoring antegrade renal perfusion. The brachial sheath is removed at the end of the procedure, and the brachial artery is repaired in standard manner.

Potential technical hazards include insufficient inflow through the sheath, kinking of the extension line, dislodgement of one shunt limb, excessive balloon inflation, and interference with the proximal aortic suture line. Although no shunt migration occurred in our initial experience, accidental displacement remains a potential risk. Continuous visual control of the renal ostia and supervision of the extracorporeal circuit by the assistant are recommended throughout the proximal reconstruction.

The present technique requires direct cannulation of the renal artery ostia, which carries a potential risk of renal artery dissection or ostial injury. Therefore, careful and atraumatic cannulation is essential.

These issues can usually be anticipated by preparing the circuit before clamping, keeping the extension line short, positioning the shunt under direct vision, and maintaining communication between the surgeon performing the aortic reconstruction and the assistant controlling the circuit.

Initial clinical experience

Between January and May 2026, five consecutive patients underwent open aortic reconstruction requiring suprarenal cross-clamping and temporary selective renal blood perfusion using the described configuration; their data were prospectively collected for this prospective observational study. All patients provided consent for the procedure and for the study. Patient characteristics and operative details are summarized in Table. Technical success was achieved in all patients. The median suprarenal warm ischemia duration before shunt deployment was 12 minutes, and the median renal perfusion duration was 35 minutes. No shunt-related complications occurred. Postoperatively, no patient developed clinically significant deterioration of renal function or required renal replacement therapy. No patient had clinical evidence of hand ischemia, brachial artery thrombosis, pseudoaneurysm, or neurologic deficit following sheath removal.

Table.

Initial clinical experience with the extracorporeal renal perfusion shunt

Variable	Patient 1	Patient 2	Patient 3	Patient 4	Patient 5
Age, years	72	78	80	73	75
Sex	Male	Male	Male	Male	Male
Body mass index, kg/m2	21	25	23	25	24
Preoperative CKD, eGFR < 60 mL/min/1.73 m2	No	Yes	Yes	Yes	No
Aortic pathology	J-AAA	J-AAA	J-AAA	EVAR explant	Aortoiliac occlusive disease
Procedure performed	Aorto bisiliac bypass	Aorto bisiliac bypass	Aorto-aorto bypass	Aorto bisiliac bypass	Aorto bifemoral bypass
Suprarenal clamp time, minutes	10	15	12	16	11
Renal perfusion time, minutes	30	35	35	40	35
Unilateral/bilateral renal perfusion	Bilateral	Unilateral—monorenal patient	Bilateral	Bilateral	Bilateral
Technical success	Yes	Yes	Yes	Yes	Yes
Preoperative creatinine, mg/dL	1.1	1.7	1.4	1.5	1.0
POD1 creatinine, mg/dL	1.1	1.6	1.5	1.5	1.0
Peak postoperative creatinine, mg/dL	1.2	1.8	1.6	1.5	1.0
Preoperative eGFR, mL/min/1.73 m2	80	58	49	55	70
Discharge eGFR, mL/min/1.73 m2	78	55	50	43	72
KDIGO AKI stage	0	0	0	0	0
Renal replacement therapy	No	No	No	No	No
Shunt-related complication	No	No	No	No	No
Length of stay, days	5	16	7	8	11
30-day mortality	No	Yes	No	No	No

AKI, Acute kidney injury; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; EVAR, endovascular aneurysm repair; J-AAA, juxtarenal abdominal aortic aneurysm; KDIGO, Kidney Disease Improving Global Outcomes; POD1, postoperative day 1.

Video presentation

The Supplementary Video (online only) provides a step-by-step demonstration of the technique and is intended to facilitate reproducibility. The first part shows the operative exposure and preparation of the inflow source, including the brachial artery cut-down and the insertion of the 9F introducer sheath. The second part illustrates the assembly of the extracorporeal circuit, including connection of the brachial sheath to the sterile extension line and to the T-port of the Pruitt-Inahara shunt.

The video then demonstrates the intra-abdominal phase. After suprarenal clamping and opening of the aorta, the renal artery ostia are identified, and the two distal limbs of the shunt are inserted directly into the renal arteries. Inflation of the independently controlled balloons secures the shunt within the ostia and facilitates continuous selective renal blood perfusion while the proximal aortic reconstruction is completed. The final part of the video shows the removal of the shunt before completion of the proximal suture line and repositioning of the clamp onto the graft, with the restoration of direct renal perfusion.

The key educational messages are the preparation of the circuit before clamping, gentle handling of the renal ostia, avoidance of excessive balloon inflation, maintenance of a short and unkinked inflow line, and coordinated removal of the shunt at the end of the proximal anastomosis.

Discussion

The present report describes a simplified extracorporeal shunt configuration for temporary selective renal blood perfusion during open aortic surgery requiring suprarenal cross-clamping. The main value of the technique is not conceptual novelty, because temporary passive shunting and selective renal perfusion have been described previously, but practical reproducibility. The configuration uses devices that are commonly available in vascular operating rooms and can be assembled rapidly without any pump, perfusion console, graft anastomosis, or dedicated visceral perfusion platform.

Renal protection during suprarenal clamping remains controversial^1,2 because not all patients require adjunctive perfusion. Several clinical studies have demonstrated acceptable renal outcomes with suprarenal clamp durations approaching 30 to 50 minutes in patients with preserved baseline renal function.

However, in complex aortic surgery, the clamp duration may be difficult to predict. Dense calcification, inflammatory aneurysms, hostile proximal necks, redo surgery, or bleeding may transform an expected short clamp interval into a longer period of renal ischemia. In these circumstances, a readily available perfusion adjunct may be valuable, particularly when it can be deployed without substantially increasing operative complexity.

Cold crystalloid perfusion remains a preferred strategy in many centers because it is inexpensive, technically straightforward, and supported by extensive clinical experience. The technique described in this report should not be interpreted as a replacement for cold renal perfusion. Rather, it represents an adjunctive option for select situations in which continuous oxygenated blood perfusion is desirable or when cold perfusion has not been prepared. Compared with intermittent crystalloid administration, passive blood perfusion provides continuous inflow and avoids repeated cannulation or infusion cycles. Conversely, it does not provide hypothermic metabolic suppression, and the delivered flow is lower than physiological renal blood flow. These differences should be considered when selecting the appropriate strategy for each patient.^1,2

Similar to cold crystalloid perfusion, the present technique requires direct renal ostial cannulation. Therefore, this step of the procedure is not simplified in this technique. Its principal advantage is the rapid assembly of a continuous blood perfusion circuit using readily available operating-room devices once the renal arteries have been exposed. Previous reports of extracorporeal or passive shunting have demonstrated that temporary arterial inflow can be used to maintain visceral or renal perfusion during complex aortic surgery. Some techniques rely on sutured grafts, axillary inflow, larger sheaths, dialysis access sheaths, or specifically designed distal perfusion catheters. These approaches may achieve higher flow rates and may be preferable when prolonged visceral perfusion is anticipated, such as in extensive thoracoabdominal aortic repair. The present configuration is more limited in flow but simpler in logistics. Its potential role is therefore different: it may serve as a rapid, off-the-shelf, selective renal blood perfusion method during abdominal open aortic repair when suprarenal clamping is required and a dedicated perfusion system is not available or not justified.^3,5,6

The technique is not intended for routine use during every suprarenal cross-clamp. Instead, it may be most appropriate when prolonged renal ischemia is anticipated or becomes unexpectedly necessary because of difficult proximal reconstruction, hostile anatomy, inflammatory disease, redo surgery, or bleeding. Patients with pre-existing chronic kidney disease or a solitary functioning kidney may theoretically derive greater benefit from continuous renal blood perfusion, although this hypothesis requires confirmation in larger clinical studies.

The use of a 9F brachial sheath is a deliberate compromise between invasiveness and flow. Larger access devices may improve inflow but may also increase access-related morbidity and preparation time. The Pruitt-Inahara shunt offers two features that are useful in this setting: a central T-port for arterial inflow and two independently controlled balloons that stabilize the limbs within the renal artery ostia. This configuration facilitates bilateral renal perfusion through a single inflow source. Careful balloon inflation is essential because the renal ostia may be fragile, calcified, or atherosclerotic. Direct visual control throughout the procedure is therefore mandatory.

The initial experience presented here is limited and should be interpreted cautiously. Five patients are insufficient to establish the efficacy of the technique or to demonstrate its superiority over other renal protection strategies. In addition, the technique does not provide the direct measurement of renal parenchymal perfusion, oxygen delivery, or renal venous outflow. The estimated flow in the circuit is lower than normal renal blood flow, and the relationship between low-flow warm blood perfusion and clinically meaningful renal protection remains uncertain. These limitations are precisely why prospective data collection is necessary.

Despite these limitations, the feasibility of the technique is clinically relevant. A technique that can be assembled quickly and used safely in selected patients may be useful even before definitive comparative data are available, provided its indications are clearly defined and its limitations are acknowledged. The ongoing prospective registry will focus on technical success, renal perfusion time, suprarenal clamp time, postoperative creatinine kinetics, Kidney Disease Improving Global Outcomes acute kidney injury, need for renal replacement therapy, access-related complications, and 30-day outcomes. Future studies should compare this approach with standard strategies, evaluate the optimal sheath size and circuit configuration, and identify patient subgroups that are most likely to benefit from this technique.

Compared with previously described radial renal shunts, passive axillary shunts, or other retrogradely shunting techniques, the principal advantage of the present configuration is its logistical simplicity. The entire circuit can be assembled within minutes using devices that are routinely available in most vascular operating rooms without requiring additional vascular anastomoses or dedicated perfusion equipment.

Conclusions

A simplified extracorporeal shunt configuration using brachial arterial inflow and a Pruitt-Inahara shunt is a feasible method for temporary selective renal blood perfusion during open aortic surgery requiring suprarenal cross-clamping. The technique is rapidly assembled from standard operating-room devices and may be considered as an adjunct in select clinical scenarios. Further prospective evaluation is required to determine its effect on postoperative renal outcomes.

Funding

None.

Declaration of generative AI and AI-assisted technologies in the writing process

During preparation of this work, the authors used ChatGPT (OpenAI) for language editing and manuscript development. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the publication.

Disclosures

None.

Appendix (online only)

Supplementary Video

Step-by-step demonstration of the simplified extracorporeal shunt configuration for temporary selective renal blood perfusion during open aortic surgery. The video shows the surgical exposure of the right brachial artery and the insertion of a 9F introducer sheath, assembly of the extracorporeal circuit by connecting the brachial sheath to the T-port of a 9F Pruitt-Inahara shunt through a sterile extension line, and selective cannulation of the renal artery ostia following suprarenal aortic cross-clamping. Inflation of the independently controlled balloons secures the shunt within the renal artery ostia, facilitating continuous selective renal blood perfusion during proximal aortic reconstruction.