Source: Synthesis of Wolff/Hölzle, Raising of Microvascular Flaps, 2nd ed. (Chapter 7), Urken’s modifications [1-3], classic DCIA flap reports [4, 5], and AO Foundation/University of Iowa protocols [6, 7].

Coauthors: Data collection: Dr. Liming Gou, Gemini | Drafting: Gemini | Revision: ChatGPT | Additional revision: Claude | Final review: Dr. Liming Gou

Introduction

The iliac crest is a workhorse donor site for complex composite defects, particularly in head and neck reconstruction. The Deep Circumflex Iliac Artery (DCIA) serves as the robust vascular pedicle for three main variations of this flap:

1. Iliac Crest Bone Flap: Bone only (mandible/maxilla reconstruction).
2. Iliac Osteocutaneous Flap: Bone + Skin paddle (composite defects).
3. Iliac Myo-Osteocutaneous Flap: Bone + Skin + Internal Oblique Muscle (complex oromandibular defects requiring extensive soft tissue/lining).

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Quick Reference: Key Anatomical Measurements

Parameter	Value	Notes
DCIA artery diameter	1.5–3.0 mm	At origin from external iliac
DCIA vein diameter	Slightly larger than artery	Usually 2.0–3.5 mm
Pedicle length	4–7 cm	May extend to 6–7 cm with careful dissection [8]
Ascending branch origin	Within a few cm medial to ASIS	Arises 40–60+ mm from DCIA origin in most cases [9]
Maximum bone dimensions	15 × 6 cm (or 16–18 × 6–8 cm)	Bicortical; cancellous core [10]
Perforator concentration zone	8–10 cm posterior to ASIS	Critical for skin paddle placement
Skin paddle axis	2.5 cm superior/medial to crest	Design for primary closure
Iliacus cuff thickness	1–2 cm inferior to DCIA	Protects vessel during osteotomy
Muscle cuff width	~2.5 cm	Contains musculocutaneous perforators

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Comparison Table: DCIA Flap Types

Feature	Bone-Only Flap	Osteocutaneous Flap	Myo-Osteocutaneous Flap
Components	Bone + periosteum + iliacus cuff	Bone + skin paddle + muscle cuff	Bone + skin paddle + internal oblique
Primary Indication	Structural bone defects only	Composite defects (bone + external skin/mucosa)	Through-and-through oromandibular defects
Soft Tissue Volume	Minimal	Moderate (skin paddle)	Maximum (muscle for lining + skin)
Pedicle Used	Main DCIA	Main DCIA + perforators	Main DCIA + ascending branch
Technical Complexity	Lower	Moderate	Highest
Skin Paddle Reliability	N/A	Variable; depends on perforators	Variable; requires intact muscle cuff
Donor Site Morbidity	Lower	Moderate	Highest (hernia risk; consider mesh)
Abdominal Wall Defect	Minimal	Moderate	Significant (internal oblique removed)

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Flap Selection: DCIA vs. Fibula vs. Scapula

Overview

According to PubMed, a network meta-analysis of 1,513 patients found comparable survival rates among DCIA (93.1%), fibula (94.5%), scapula (97%), and radial forearm (96%) flaps for mandibular reconstruction (DOI) [11]. Flap selection should be based on defect characteristics, soft tissue needs, and patient factors rather than survival rates alone.

Selection Algorithm

Step 1: Assess Bone Defect Location

Defect Type	Preferred Flap	Rationale
Lateral mandible (angle/ramus)	DCIA or Scapula	DCIA provides natural curvature; scapula for large soft tissue
Anterior mandible (symphysis crossing midline)	Fibula	Multiple osteotomies feasible; long bone stock
Combined anterior + lateral	Fibula ± second flap	Fibula allows multiple segments

Step 2: Assess Soft Tissue Requirements

Soft Tissue Need	Preferred Flap	Notes
None (bone only)	DCIA (bone-only)	Superior bone height/volume for implants
Small skin/mucosal paddle	Fibula	Reliable septocutaneous perforators
Large external skin	Scapula	Generous, reliable skin territory
Through-and-through defect	DCIA with internal oblique OR Scapula	Internal oblique provides lining; scapula tip + skin

Step 3: Consider Patient Factors

Factor	Flap Consideration
Peripheral vascular disease	Avoid fibula (check ankle-brachial index)
Prior abdominal/inguinal surgery	DCIA contraindicated or high-risk
Ambulatory concerns	Fibula may affect gait; DCIA affects hip
Need for dental implants	DCIA provides superior bone height (DOI) [12]
Obesity	DCIA skin paddle less reliable; consider fibula

Key Comparative Points (Evidence-Based)

• DCIA advantages: Greater bone height/width mimicking native mandible; bicortical structure with cancellous core ideal for implants; up to 15 cm bone length (DOI) [13].
• DCIA disadvantages: Shorter pedicle (4–7 cm); skin paddle less reliable; higher donor site morbidity including hernia risk (trend toward increased hernia without mesh: p=0.059) (DOI) [14]; regional dysesthesia more common than fibula (DOI) [15].
• Fibula advantages: Long bone (up to 25 cm); reliable skin paddle; long pedicle; allows multiple osteotomies; lower complication rate.
• Fibula disadvantages: Cortical bone only (may require double-barrel for height); ankle donor morbidity.
• Scapula advantages: Large soft tissue territory; reliable vasculature; separate bone and skin paddles allow 3D positioning.
• Scapula disadvantages: Patient repositioning often required; limited bone length (~10–14 cm).

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Pre-operative Planning (Brief)

• History/Exam: Prior abdominal or inguinal surgery, hernia, or pelvic trauma increases donor-site risk.
• Markings: ASIS, iliac crest, pubic tubercle, and femoral pulse should be clearly marked before prepping.
• Skin Paddle: Design for primary closure; use a pinch test.
• Perforator Mapping: Handheld Doppler can be used to confirm dominant perforators.
• Imaging (Selective): Consider CTA if prior surgery, vascular disease, or atypical anatomy is suspected.

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Part 1: Iliac Crest Bone Flap

Overview

The standard bone flap is used when only structural reconstruction is required. It offers a large volume of bicortical bone.

Patient Positioning

The patient is placed in the supine position. A beanbag is used to elevate the buttocks on the donor site. The operating field is prepared between the midline, posterior axillary line, lower rib arch, and upper thigh.

Flap Design

• Bone Dimensions: Up to 6–8 × 16–18 cm.
• Landmarks: Anterior Superior Iliac Spine (ASIS) is crucial for forming the angle in mandibular reconstruction.
• Incision: Outlined 2 cm superior to the connection of the pubic tubercle and the ASIS, starting just lateral to the femoral artery pulse, extending distally above the iliac crest curvature.

Surgical Steps

Step 1: Initial Incision and Exposure

• Incise the skin and subcutaneous fatty tissue between the femoral artery and the ASIS.
• Identify the inguinal ligament.
• Note: Ligate and divide superficial epigastric vessels if they cross the incision line.
• Critical Warning: Ensure the incision is not made caudal to the line between the pubic tubercle and ASIS to avoid opening the femoral trigonum or injuring motor branches of the femoral nerve.

Step 2: Incision of Inguinal Ligament

• Incise the inguinal ligament parallel to its fiber orientation (the inguinal ligament is the thickened inferior border of the external oblique aponeurosis).
• Expose the internal oblique muscle (visible perpendicular to inguinal ligament fibers).
• Retract skin and ligament in a cranial direction.

Step 3: Exposure of the Vascular Pedicle (DCIA)

• Transect the internal oblique muscle with scissors 2 cm superior to the line connecting the ASIS and pubic tubercle.
• Identify loose fatty tissue covering the transversalis fascia.
• Palpate the pulse of the Deep Circumflex Iliac Artery (DCIA) in the groove between the transversus and iliacus muscles.
• Expose the vascular pedicle by careful, mostly blunt separation of fatty tissue. (It is not necessary to expose the external iliac artery).
• Anatomy Note: The ascending branch may be visible first; do not mistake it for the main DCIA. It leads to the main artery if followed proximally.

Step 4: Pedicle Dissection

• Place a vessel loop around the artery (accompanied by two veins).
• Dissect the pedicle free along its course to the ASIS. Clip or ligate small muscular branches.
• Identify the ascending branch (coursing along the undersurface of the internal oblique).
• Nerve Handling: If the lateral femoral cutaneous nerve crosses above the pedicle, identify and preserve it when possible. If it must be sacrificed, counsel regarding expected anterolateral thigh numbness.

Step 5: Posterior Skin Incision

• Once the pedicle is isolated medial to the ASIS, continue the skin incision along the iliac crest to the level of the external oblique muscle.
• Tip: The incision should be at least 3 cm longer than the planned bone segment to facilitate osteotomy.

Step 6: Lateral Muscle Transection

• Palpate the lateral rim of the iliac crest.
• Transect muscles at the gluteal aspect of the pelvis.
• Perform thorough hemostasis to prevent bleeding from well-perfused muscles.

Step 7: Detachment of Hip Muscles

• Beginning anteriorly, detach the tensor fasciae latae and gluteus medius muscles epiperiosteally from the external surface of the hip using a sharp scalpel.
• Leave the sartorius muscle intact at this stage.
• Retract abdominal wall muscles cranially and bluntly undermine medial to the iliac crest.
• Safety: Maintain a dissection plane superficial to the vascular pedicle.

Step 8: Abdominal Muscle Transection

• Transect abdominal muscles 2 cm from the inner rim of the iliac crest, moving from caudal to cranial.
• Cauterize/ligate muscular branches to the internal oblique.
• Protect the Pedicle: Palpate the DCIA pulse at the inner surface of the pelvic curvature (1–3 cm inferior to the inner rim) to preserve it.
• Insert a broad abdominal hook to protect and retract the content of the peritoneum.

Step 9: Iliacus Muscle Incision

• Palpate the DCIA course in the groove between transversus and iliacus muscles.
• Sharply transect the iliacus muscle to the periosteum about 1–2 cm below the artery.
• Perfusion Note: A small iliacus cuff (about 1 cm) is usually adequate for perfusion; avoid stripping periosteum adjacent to the pedicle.

Step 10: ASIS Detachment

• Continue muscular detachment at the ASIS.
• Transect the sartorius muscle directly at its origin from the bone.
• Critical: Carefully protect the vascular pedicle enveloped in fascia between the iliacus and transversus muscles in the ASIS region.

Step 11: Distal Osteotomy

• Begin osteotomy distally at the iliac crest using an oscillating saw (avoid chisels).
• Cut through inner and outer cortical bone to the desired depth.
• Retract soft tissues with broad hooks to visualize the blade and protect the peritoneum.
• Ligate the distal continuation/branches of the DCIA at the posterior limit of the flap as needed; do not divide the main pedicle until transfer.

Step 12: Anterior Osteotomy

• Continue cutting bone bicortically in an anterior direction, keeping a parallel distance from the upper rim of the iliac crest.
• Safety: Insert the saw caudal enough on the lateral aspect so the vascular pedicle is not injured when penetrating the inner cortex.
• For mandibular angle/ramus construction: Continue osteotomy parallel to the anterior rim up to a depth of 6–8 cm.

Step 13: Flap Elevation

• Elevate the osteotomized bone segment.
• Transect residual muscle fibers.
• Dissect the vascular pedicle medially close to the external iliac vessels.
• Ligate the ascending branch only if no internal oblique component is planned.
• Keep the venae comitantes with the artery; separate only if additional length or specific anastomotic configuration is required.
• Hemostasis: Use bone wax on the cutting surface of the pelvis.

Step 14: Transfer and Closure

• Maintain flap perfusion until recipient vessels are ready.
• Donor Site Closure:
  • Insert a deep drain.
  • Attach iliacus muscle to transversus muscle using deep sutures (can use drill holes along the cut margin).
  • Approximate internal/external oblique muscles to tensor/gluteus muscles.
  • Close subcutaneous tissue and skin in layers.
• Post-op: Mobilize per institutional protocol; many centers begin early ambulation once pain is controlled while avoiding excessive hip flexion/extension initially.

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Part 2: Iliac Osteocutaneous Flap

Overview

Adds a skin paddle to the bone flap. Key Difference: The critical requirement is to preserve the "obligatory muscle cuff" containing the perforators that connect the DCIA (running along the inner iliac crest) to the skin paddle (on the outer/superior aspect).

Anatomy & Pre-operative Marking

• Vascular Basis: DCIA musculocutaneous perforators piercing the abdominal wall. Concentrated 8-10 cm posterior to the ASIS.
• Flap Design:
  • Draw the skin paddle axis roughly 2.5 cm superior and medial to the iliac crest.
  • Pinch Test: Ensure primary closure of the donor site is possible.

Surgical Steps

Step 1: Superior Incision and Muscle Exposure

• Incise the superior border of the skin paddle first (the abdominal side).
• Dissect through the subcutaneous fat down to the external oblique aponeurosis.
• Critical Safety Point: Do NOT undermine the skin paddle from the underlying muscles in the zone between the incision and the iliac crest. The skin must remain attached to the external oblique muscle fascia here to preserve perforators.

Step 2: Inguinal Exposure and Pedicle Isolation

• Extend the incision medially towards the femoral vessels.
• Incise the inguinal ligament and transversalis fascia to enter the retroperitoneal space.
• Identify the DCIA and DCIV arising from the external iliac vessels.
• Isolate the pedicle and follow it laterally towards the ASIS.

Step 3: Defining the "Muscle Cuff"

• Incise the external oblique, internal oblique, and transversus abdominis muscles approximately 2-3 cm cranial to the iliac crest (or along the superior margin of the skin paddle).
• This cut connects the external dissection (Step 1) with the inner retroperitoneal space (Step 2).
• Result: You now have a "bridge" of abdominal wall muscles attaching the skin paddle to the iliac crest.

Step 4: Inner (Pelvic) Dissection

• Retract the peritoneum medially.
• Trace the DCIA along the inner aspect of the iliac crest.
• Incise the iliacus muscle and periosteum on the inner table of the ilium.
• The incision is typically 2 cm inferior to the DCIA to ensure the vessel is included in the flap and protected by a cuff of iliacus muscle.

Step 5: Inferior (Lateral) Incision

• Incise the inferior border of the skin paddle (the gluteal/thigh side).
• Dissect down to the tensor fasciae latae (TFL) and gluteus medius fascia.
• Unlike the superior side, you can elevate the skin here toward the iliac crest; stay subfascial to avoid injuring the perforators that course from the muscle cuff.
• Transect the TFL and gluteus medius muscles from the outer table of the ilium at the level of the proposed osteotomy.

Step 6: Osteotomy

• With the inner and outer tables exposed (and the muscle cuff protected superiorly), perform the bone cuts.
• Distal/Posterior Cut: Vertical cut through the crest at the posterior limit of the flap.
• Anterior Cut: Vertical cut at the ASIS or inclusion of the ASIS/spine depending on reconstruction needs.
• Horizontal Cut: Connect the vertical cuts inferiorly (typically 6-8 cm depth) using an oscillating saw.
• Safety: Use broad retractors (malleable) on the inner side to protect the abdominal contents and on the outer side to protect soft tissues.

Step 7: Flap Harvest

• Gently mobilize the bone segment.
• Verify that the DCIA pedicle, the iliacus muscle cuff (inner), the abdominal muscle cuff (superior), and the skin paddle are all moving as a single unit.
• Divide the vascular pedicle at the external iliac vessels when the recipient site is ready.

Step 8: Donor Site Closure (Critical)

• Hernia prevention is the priority.
• Bone: Wax the cut bony edges.
• Deep Layer: Suture the transversalis fascia and transversus abdominis to the remaining iliacus muscle and/or drill holes in the cut pelvic bone.
• Middle Layer: Suture the internal oblique to the gluteus medius/TFL fascia.
• Superficial Layer: Suture the external oblique to the tensor fasciae latae.
• Close the skin. A mesh reinforcement may be necessary if the abdominal wall defect is large or tension is high.

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Part 3: Iliac Myo-Osteocutaneous Flap

Overview

The most comprehensive version, including the internal oblique muscle. This flap is valued for through-and-through oromandibular defects. The internal oblique muscle, supplied by the ascending branch of the DCIA, can be moved independently of the bone to provide intraoral lining.

Surgical Steps

Step 1: Flap Design and Incision

• Markings: ASIS, iliac crest, pubic tubercle, and femoral artery.
• Skin Paddle: Outline the skin paddle roughly 2.5 cm parallel and medial to the iliac crest.
• Muscle Marking: The internal oblique muscle territory extends superiorly from the iliac crest towards the rib cage.
• Initial Incision: Extend the skin incision superiorly beyond the skin paddle to allow wide exposure of the abdominal wall muscles.

Step 2: Exposure of the Internal Oblique Muscle

• Incise through the skin and subcutaneous fat.
• Identify and incise the external oblique muscle and its aponeurosis.
• Retract the external oblique to fully expose the underlying internal oblique muscle (fibers run superomedially, perpendicular to the external oblique).
• Identify the desired dimensions of the internal oblique muscle needed for reconstruction.

Step 3: Harvesting the Internal Oblique Component

• The internal oblique is separated from the deeper transversus abdominis muscle.
• Identifying the Ascending Branch: This vessel is the key to the muscle component. It often arises within a few centimeters medial to the ASIS and runs on the deep surface of the internal oblique.
• Carefully elevate the internal oblique muscle from medial to lateral, ensuring the ascending branch and its connections to the main DCIA trunk are preserved.
• Leave the muscle attached to the iliac crest (the "muscle cuff") to maintain its vascular continuity and to preserve the musculocutaneous perforators going to the skin paddle.

Step 4: Pedicle Dissection (DCIA/DCIV)

• Dissect medially to the ASIS to identify the origin of the DCIA and DCIV from the external iliac vessels.
• Trace the vessels laterally. Ensure the ascending branch (supplying the internal oblique) and the main DCIA trunk (supplying the bone and skin perforators) are both maintained.
• Ligate any branches not contributing to the flap components.

Step 5: Preserving the "Obligatory" Muscle Cuff

• To ensure the skin paddle remains viable, you must maintain a full-thickness "cuff" of the three abdominal muscles (transversus, internal oblique, and external oblique) where they attach to the iliac crest.
• This cuff (approx. 2.5 cm wide) contains the musculocutaneous perforators that "bridge" the DCIA to the skin.

Step 6: Inner (Pelvic) and Outer Dissection

• Inner Table: Retract the peritoneum. Incise the iliacus muscle 1-2 cm inferior to the DCIA course to include a protective muscle cuff on the inner bone.
• Outer Table: Reflect the tensor fasciae latae and gluteus medius muscles from the lateral aspect of the ilium.
• Sartorius: Transect the sartorius muscle at its origin from the ASIS.

Step 7: Osteotomy

• Perform the bone cuts (anterior, posterior, and inferior) as planned for the reconstruction.
• Use an oscillating saw, keeping a safe distance from the vascular pedicle.
• Verification: The bone, the internal oblique muscle (attached by the ascending branch), and the skin paddle (attached by the muscle cuff) should now be mobile as a single complex pedicled on the DCIA/V.

Step 8: Flap Delivery

• Ligate the distal continuation of the DCIA/V.
• When the recipient site is ready, divide the pedicle at the external iliac vessels.
• The internal oblique muscle can now be rotated or folded independently of the bone/skin to fit the 3D requirements of the defect.

Step 9: Donor Site Closure and Hernia Prevention

• This is the most critical part of the donor site management due to the significant muscle harvest.
• Layered Repair: Suture the transversalis fascia and remaining transversus abdominis to the iliacus muscle or through drill holes in the bone.
• The external oblique is sutured to the gluteus fascia/TFL.
• Mesh: Strong consideration should be given to using a non-absorbable or composite synthetic mesh to reinforce the abdominal wall, as a significant portion of the internal oblique has been removed.
• Close subcutaneous tissue and skin over multiple suction drains.

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Donor-Site Morbidity and Prevention

• Abdominal Wall Weakness/Bulge/Hernia: Risk increases with large muscle harvest or a wide cuff; meticulous layered closure and mesh reinforcement when needed.
• Sensory Changes: Lateral femoral cutaneous nerve traction or sacrifice can cause meralgia paresthetica or numbness; identify/preserve when feasible and counsel patients.
• Pelvic Stability/Fracture Risk: Avoid excessive bone length or harvesting the ASIS unless required; maintain bony bridges and use gentle osteotomy technique.
• Gait Pain/Contour Deformity: Reattach TFL, sartorius, and gluteus medius to the crest or fascia; restore abdominal wall tension.
• Hematoma/Seroma/Infection: Achieve hemostasis and place closed-suction drains.

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Postoperative Protocol

Immediate Postoperative Care (Days 0–3)

• Wound Care: Maintain closed-suction drains until output <30 mL/24h (typically 3–5 days).
• Pain Management: Multimodal analgesia; early donor-site pain (VAS 4–5/10 on POD1) is common and affects ambulation.
• Positioning: Avoid excessive hip flexion initially; semi-Fowler’s position acceptable.
• Thromboprophylaxis: Per institutional protocol (mechanical + pharmacologic as indicated).

Ambulation and Weight Bearing

Timeframe	Activity	Notes
POD 1	Isometric quadriceps, ankle pumps, straight leg raises	Bedside with assistance
POD 1–3	Ambulation with assistance	Expect gait deviation/limp
Week 1	Toe-touch weight bearing	Progress as tolerated
Week 2	Partial weight bearing	Most patients ambulatory without support
Week 4+	Full weight bearing	Hip ROM typically normalized by 6–8 weeks

Note: Patients may experience discomfort with ambulation for up to 8 weeks postoperatively [16].

Activity Restrictions

• Hip flexion/extension: Avoid extreme ranges for 2–4 weeks.
• Heavy lifting: Avoid for 6–8 weeks (hernia prevention).
• Return to work: Sedentary work at 2–4 weeks; physical labor at 6–12 weeks depending on recovery.

Monitoring for Complications

• Abdominal wall: Inspect for bulge/hernia at each follow-up; instruct patient on self-examination.
• Wound: Monitor for hematoma, seroma, infection, dehiscence.
• Neurologic: Document lateral thigh sensation; counsel that dysesthesia may persist or improve over 6–12 months.

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Intraoperative Troubleshooting

Pedicle-Related Issues

Problem	Possible Cause	Solution
Cannot locate DCIA	Variant anatomy; artery too deep	Palpate groove between transversus/iliacus; consider following ascending branch proximally; may share trunk with SCIA
Pedicle too short	Need additional length for recipient vessels	Dissect more proximally toward external iliac; separate venae comitantes if needed; accept 4–7 cm as typical
Arterial spasm	Mechanical trauma; cold	Topical papaverine or lidocaine; warm saline irrigation; gentle handling
Venous congestion	Venous outflow obstruction	Confirm both venae comitantes patent; consider using both veins for anastomosis; check for kinking

Skin Paddle Issues

Problem	Possible Cause	Solution
Poor skin paddle perfusion	Perforators injured; inadequate muscle cuff	Verify muscle cuff intact (≥2.5 cm); do NOT undermine superior skin edge; Doppler perforators preop
No audible perforators on Doppler	Anatomic variation; obese patient	Consider bone-only flap; alternative flap (fibula); intraoperative ICG angiography if available
Skin paddle too bulky	Thick subcutaneous tissue	Primary thinning risky (perforators run in fat); thin at second stage or accept bulk

Bone/Osteotomy Issues

Problem	Possible Cause	Solution
Bleeding from bone edges	Exposed marrow	Bone wax; ensure adequate hemostasis before closure
Inadequate bone length	Defect larger than anticipated	Harvest more posteriorly if anatomy permits; may need alternative flap
Difficult osteotomy	Dense cortical bone	Use sharp oscillating saw blade; copious irrigation; avoid chisel
Peritoneal breach	Saw penetration too deep	Primary repair with absorbable suture; ensure no bowel injury

Anatomic Variants

• Ascending branch: In ~80% of cases, a single ascending branch supplies internal oblique; in ~20%, 2–3 branches arise separately (DOI) [8].
• DCIA origin: May arise independently or share a common trunk with superficial circumflex iliac artery (SCIA).
• Lateral femoral cutaneous nerve: Variable course; may cross superficial or deep to pedicle—identify early.

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Educational Resources and Anatomical References

Recommended Surgical Videos and Atlases

• AO Surgery Reference: DCIA Flap Technique — Step-by-step illustrations and videos.
• Microsurgeon.org: DCIA Bone Flap Overview — Anatomy, technique, and tips.
• University of Iowa Protocols: Iliac Crest Flap — Institutional protocols.

Key Anatomical Landmarks (Diagram Reference Points)

1. Anterior Superior Iliac Spine (ASIS): Origin of sartorius; key landmark for mandibular angle reconstruction.
2. Pubic Tubercle: Medial limit; incision stays 2 cm superior to ASIS–pubic tubercle line.
3. Inguinal Ligament: Inferior border of external oblique aponeurosis; incise parallel to fibers.
4. Femoral Artery Pulse: Lateral border of femoral triangle; stay lateral to avoid injury.
5. Groove between Transversus and Iliacus: DCIA runs here; palpate pulse to locate.
6. Perforator Zone: 8–10 cm posterior to ASIS on iliac crest—critical for skin paddle design.

Suggested Reading (PubMed-Indexed)

• Urken et al. (1989) — Internal oblique-iliac crest flap for oromandibular defects (DOI)
• Ramasastry et al. (1986) — Clinical anatomy of internal oblique muscle (DOI)
• Mashrah et al. (2021) — Network meta-analysis of osseous flap survival (DOI)
• Wilkman et al. (2018) — Clinical comparison of scapular, fibular, and iliac crest flaps (DOI)
• Schulte et al. (2023) — DCIA length, diameter, and stenosis on DSA (DOI)

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OR Checklist: DCIA Flap Harvest

Pre-Incision

• Patient supine, buttock elevated with beanbag, hip externally rotated
• Landmarks marked: ASIS, pubic tubercle, iliac crest, femoral pulse
• Skin paddle outlined (if applicable): 2.5 cm superior/medial to crest; pinch test passed
• Perforators confirmed with Doppler (osteocutaneous/myo-osteocutaneous)
• Recipient vessels prepared or preparation underway
• Bone cutting instruments available: oscillating saw, blades, bone wax
• Vascular instruments ready: vessel loops, microvascular clamps, heparinized saline

Pedicle Dissection

• Incision 2 cm superior to ASIS–pubic tubercle line
• Inguinal ligament incised parallel to fibers
• DCIA/DCIV identified and vessel-looped
• Ascending branch identified (preserve if muscle component needed)
• Lateral femoral cutaneous nerve identified and protected (if possible)

Bone Harvest

• Abdominal wall muscles transected 2 cm from inner iliac rim
• Iliacus incised 1–2 cm inferior to DCIA
• Peritoneum protected with broad retractor
• Osteotomies completed with oscillating saw (anterior, posterior, inferior)
• Bone segment mobilized; pedicle intact

Skin Paddle (if applicable)

• Superior skin edge NOT undermined toward crest (perforators preserved)
• Muscle cuff intact (≥2.5 cm width)
• All components (bone, skin, ± muscle) moving as single unit

Flap Division

• Recipient site confirmed ready
• Distal DCIA branches ligated
• Pedicle divided at external iliac vessels
• Flap transferred; ischemia time recorded

Donor Site Closure

• Bone wax applied to cut edges
• Layered closure: transversalis/transversus → iliacus; internal oblique → gluteus/TFL; external oblique → TFL
• Mesh placed if large abdominal wall defect (especially myo-osteocutaneous)
• Closed-suction drain placed
• Subcutaneous and skin closure completed

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References

1. Urken ML, Vickery C, Weinberg H, et al. The internal oblique-iliac crest osseomyocutaneous free flap in oromandibular reconstruction. Arch Otolaryngol Head Neck Surg. 1989;115(3):339-49. doi: 10.1001/archotol.1989.01860270081019.
2. Urken ML, Vickery C, Weinberg H, et al. The internal oblique-iliac crest osseomyocutaneous microvascular free flap in head and neck reconstruction. J Reconstr Microsurg. 1989;5(3):203-14; discussion 215-6. doi: 10.1055/s-2007-1006869.
3. Urken ML, Weinberg H, Vickery C, et al. The internal oblique-iliac crest free flap in composite defects of the oral cavity involving bone, skin, and mucosa. Laryngoscope. 1991;101(3):257-70. doi: 10.1288/00005537-199103000-00007.
4. Bitter K. Bone transplants from the iliac crest to the maxillo-facial region by the microsurgical technique. J Maxillofac Surg. 1980;8(3):210-16. doi: 10.1016/S0301-0503(80)80103-2.
5. Franklin JD, Shack RB, Stone JD, et al. Single-stage reconstruction of mandibular and soft tissue defects using a free osteocutaneous groin flap. Am J Surg. 1980;140(4):492-8. doi: 10.1016/0002-9610(80)90198-1.
6. AO Surgery Reference. Deep Circumflex Iliac Artery (DCIA) Flap. Available at: https://surgeryreference.aofoundation.org/ (accessed 2026-01-18).
7. University of Iowa Head and Neck Protocols. Iliac Crest Osteocutaneous Flap. Available at: https://medicine.uiowa.edu/iowaprotocols/ (accessed 2026-01-18).
8. Ramasastry SS, Granick MS, Futrell JW. Clinical anatomy of the internal oblique muscle. J Reconstr Microsurg. 1986;2(2):117-22. doi: 10.1055/s-2007-1007012.
9. Schulte R, Loberg C, Ghassemi A. Evaluating the length, diameter, and stenosis of deep circumflex iliac artery and neighboring arteries based on digital subtraction angiography. Microsurgery. 2023;43(4):373-381. doi: 10.1002/micr.31022.
10. Microsurgeon.org. Deep Circumflex Iliac Artery (DCIA) Bone Flap. Available at: https://www.microsurgeon.org/dcia (accessed 2026-01-18).
11. Mashrah MA, Aldhohrah T, Abdelrehem A, et al. Survival of vascularized osseous flaps in mandibular reconstruction: A network meta-analysis. PLoS One. 2021;16(10):e0257457. doi: 10.1371/journal.pone.0257457.
12. Mertens C, Decker C, Engel M, et al. Early bone resorption of free microvascular reanastomized bone grafts for mandibular reconstruction—a comparison of iliac crest and fibula grafts. J Craniomaxillofac Surg. 2014;42(5):e217-23. doi: 10.1016/j.jcms.2013.08.010.
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