Aortobifemoral Bypass

CPT 35646
Approach Open
Add-on / Variant CPTs
  • 35647 — Bypass graft, aortofemoral (unilateral)
  • 35700 — Reoperation peripheral bypass, add-on
Preoperative Diagnosis:

Aortoiliac occlusive disease (AIOD) — [TransAtlantic Inter-Society Consensus (TASC) C/D lesion] with bilateral lower extremity [claudication / rest pain / tissue loss / Leriche syndrome]

Postoperative Diagnosis:

Same

Procedure Performed:

Aortobifemoral bypass with [16 × 8 mm / 18 × 9 mm] bifurcated [Dacron / PTFE] graft

Attending Surgeon:

[Attending name], MD/DO

First Assistant:

[Resident/PA name]

Anesthesia:

General endotracheal [/ combined epidural-general]

Indications:

The patient is a [age]-year-old [male/female] with aortoiliac occlusive disease presenting with [bilateral claudication at X meters / rest pain / tissue loss / impotence and absent femoral pulses consistent with Leriche syndrome]. Imaging (CTA) demonstrated TASC C/D aortoiliac disease not amenable to endovascular reconstruction. The risks, benefits, and alternatives including aortoiliac stenting and axillofemoral bypass were discussed and informed consent was obtained.

Findings:

The infrarenal aorta was [soft / calcified / with adequate proximal neck for anastomosis] at the [infrarenal level]. The aortic diameter at the clamp site was [X] mm. Bilateral common femoral arteries were [palpable / patent / suitable for anastomosis]. The [16 × 8 mm / 18 × 9 mm] bifurcated prosthetic graft was used. Bilateral femoral pulses and Doppler signals were confirmed on completion.

Description of Procedure:

The patient was positioned supine. A midline laparotomy was performed from the xiphoid to the pubis. The transverse colon was retracted superiorly and the small bowel packed to the right. The retroperitoneum overlying the aorta was incised from the level of the renal veins to the bifurcation. The infrarenal aorta was dissected and encircled with a vessel loop [at the infrarenal neck, below the renal arteries]. The inferior mesenteric artery was [ligated / preserved]. Bilateral common femoral arteries were exposed through vertical groin incisions.

Systemic heparin [100 units/kg] was administered and ACT confirmed >250 seconds. The aorta was cross-clamped infrarenally [and distally]. A [longitudinal / elliptical] aortotomy was made [or the aorta was divided].

The proximal end-to-end [or end-to-side] anastomosis was constructed between the [16 × 8 / 18 × 9] mm bifurcated graft and the infrarenal aorta using running [3-0 Prolene] suture. The graft limbs were tunneled retroperitoneally through the iliac fossa to the femoral triangles bilaterally, posterior to the ureters.

Distal end-to-side anastomoses were constructed to the common femoral arteries bilaterally with running [5-0 Prolene]. Clamps were sequentially released — first to the left limb, then the right. Pulses were immediately palpable in the femoral arteries and distally. Doppler confirmed bilateral distal flow.

Hemostasis was confirmed throughout. The retroperitoneum was closed over the graft with [3-0 Vicryl] to minimize risk of aortoenteric fistula. The abdomen was closed in layers. Groin wounds were closed in layers.

Complications:

None

Specimens:

None

Estimated Blood Loss:

[X] mL

Drains:

None / [JP drain in groin wound(s)]

Disposition:

The patient tolerated the procedure well and was taken to the ICU in stable condition. Bilateral lower extremity pulses were documented at case end. Heparin was [reversed with protamine X mg / not reversed]. Post-operative monitoring included hourly urine output, lower extremity pulse checks, and abdominal exam.

Epic SmartPhrase Version 
PREOPERATIVE DIAGNOSIS: Aortoiliac occlusive disease — TASC ***
POSTOPERATIVE DIAGNOSIS: Same
PROCEDURE PERFORMED: Aortobifemoral bypass — *** × *** mm bifurcated graft
ATTENDING: ***, MD/DO
ASSISTANT: ***
ANESTHESIA: General endotracheal

INDICATIONS: .PTAGE-year-old .PTSEX with aortoiliac occlusive disease — ***. TASC *** lesions on CTA. Consent obtained.

FINDINGS: Infrarenal aorta ***. CFA bilateral ***. Graft: *** × *** mm bifurcated prosthetic. Bilateral femoral pulses confirmed post-reperfusion.

PROCEDURE:
Supine. Midline laparotomy. Retroperitoneum opened, infrarenal aorta exposed. IMA ***. Bilateral femoral cutdowns. Heparin *** units/kg, ACT >250. Aortic cross-clamp infrarenal. *** aortotomy. Proximal end-to-*** anastomosis with 3-0 Prolene. Limbs tunneled retroperitoneally bilateral, posterior to ureters. Distal end-to-side anastomoses CFA bilateral with 5-0 Prolene. Clamps released — pulses confirmed bilateral. Retroperitoneum closed over graft. Abdomen closed in layers.

EBL: *** mL
COMPLICATIONS: None
DISPOSITION: ICU, bilateral pulses documented.

Signed: .ME, .MYDEGREE
.TODAY
Variants

End-to-End Proximal Anastomosis (Preferred for Occlusion)

The infrarenal aorta was divided just below the renal arteries. The distal aortic stump was oversewn with [3-0 Prolene]. An end-to-end proximal anastomosis was constructed between the graft and the divided aortic cuff. End-to-end configuration is preferred when the native aorta is occluded or severely diseased, as it eliminates the native aortic circulation from the anastomosis and reduces competing flow. It also creates a more anatomic tunnel.

Aortoiliac Endarterectomy (Alternative for Localized Disease)

For [focal / confined] aortoiliac occlusive disease, thromboendarterectomy was performed rather than bypass grafting. The aorta and iliac arteries were opened longitudinally and the atheromatous core was dissected in the endarterectomy plane. The endpoint was tacked distally with [4-0 Prolene] interrupted sutures to prevent dissection. Patch angioplasty was performed using [Dacron / bovine pericardium] patch. Endarterectomy avoids prosthetic material and is durable for limited-extent disease but is technically demanding for diffuse disease.

Charting Tips
  • Document IMA management. The inferior mesenteric artery is ligated in most cases. If the IMA was patent and large (>4 mm), document the decision to ligate vs. reimplant and whether colonic perfusion was assessed (Doppler over sigmoid, back-bleeding from IMA). Sigmoid ischemia is a feared complication.
  • Document ureter identification and protection. Both ureters must be identified prior to tunneling the graft limbs. Ureteral injury or obstruction by the graft is a serious complication. Document that the ureters were visualized and the limbs passed posterior to them.
  • Document aortic clamp time and protamine use. If protamine was given, document the dose and that no anaphylaxis occurred. Protamine is associated with hemodynamic instability in some patients (prior NPH insulin, fish allergy); document the risk assessment.
Billing Tips
  • 35540 (aortobifemoral bypass, 48.10 wRVU) is the primary code for aortoiliac occlusive disease with bilateral femoral anastomoses. This is the standard code when both limbs of the graft are anastomosed.
  • 35646 (aortobifemoral bypass graft, 32.16 wRVU) and 35647 (aortofemoral, unilateral, 28.99 wRVU): use the correct code based on your payer's preferred reporting; 35540 is most commonly used.
  • Endarterectomy of the common femoral artery performed concurrently is separately billable (35371) with modifier -51. Document each vessel endarterectomy.
  • Femoral-femoral crossover performed as an alternative (extra-anatomic) bypass uses 35473/35474, which is a distinct procedure with a distinct code. Document why anatomic bypass was chosen vs extra-anatomic.
  • Global period is 90 days. Graft surveillance duplex studies, wound care, and post-op ABI checks are bundled into the surgical fee.
  • Lumbar sympathectomy performed at the same session is separately billable (64818) with modifier -51 when documented as a distinct procedure for distal vasodilation.
  • Document: indication (claudication vs critical limb ischemia), inflow/outflow vessel selection, graft material (Dacron, ePTFE, bifurcated graft brand), anastomotic technique, and completion angiography findings.