**Region:** Trunk and Lower Back # Jejunal Flap ## Anatomy - Pedicle: superior mesenteric artery (SMA) jejunal branch and accompanying superior mesenteric vein → arterial arcades → vasa recta; veins accompany arteries and drain into the superior mesenteric vein/portal system (SMA originates ~1 cm inferior to the celiac trunk and passes posterior to the pancreatic neck and splenic vein). Caliber and length: arterial caliber reported ~1.5–2.5 mm, venous caliber ~2.0–4.0 mm; typical usable pedicle length through the mesentery ~15–20 cm (longest pedicle achievable by selecting branches ~40 cm distal to the ligament of Treitz); the segment harvestable from the ligament of Treitz to distant small bowel can extend widely (reports up to 150 cm of small bowel described) (Hanasono; Shokrollahi; Volume I). - Course: SMA → multiple jejunal branches along mesenteric border → form primary/secondary/tertiary arcades → terminal vasa recta enter bowel at mesenteric border and supply antimesenteric mucosa. The vascular pedicle is fan-shaped in the mesentery with the origin of the selected jejunal branch at the apex and the mesenteric fan toward the bowel wall (transillumination identifies chosen arcade). - Perforator pattern / angiosomes: jejunal perfusion is segmental via arcades and vasa recta. Upper jejunum commonly has a single arcade with long vasa recta; more distal jejunum/ileum show multiple arcades (two to three) with shorter vasa recta. The flap behaves as a Mathes & Nahai type I vascularized intestinal conduit (each jejunal segment supplied by a single major pedicle from the SMA) (Shokrollahi; Hanasono). - Nerves: no relevant cutaneous sensory or motor nerves are included in the harvested jejunal segment for pharyngoesophageal reconstruction; somatic nerve branches are not part of the conduit and the flap is non‑sensate for cutaneous sensation (no named sensory/motor nerves are harvested in the jejunal segment in the source texts). - Included tissues: full-thickness intestinal wall — mucosa (plicae circulares in jejunum), submucosa, muscularis (longitudinal and circular muscle layers), and serosa; thin, pliable tubular conduit with mucous‑producing epithelium. The antimesenteric border can be opened to widen the lumen (2–3 cm typical incision) or folded to increase proximal diameter. - Arc of rotation / reach: constrained by mesenteric length and location of chosen jejunal branch; single-vessel free jejunal flap length generally up to ~15–20 cm of conduit on that pedicle (some groups harvest up to 20 cm on a single arcade; supercharging is used when greater reach is required). Variants include free jejunal, pedicled jejunal with supercharging (type I–III patterns based on which mesenteric branches are divided and which remain pedicled) (Hanasono; Volume I; Shokrollahi). ## Dissection Steps 1. Positioning, markings, landmarks. - Supine patient; entire chest/abdomen/neck prepped as a single field. Upper midline epigastric incision: options described include a short midline epigastric incision (approx 8 cm above the umbilicus) for open harvest or a longer upper midline from below the xiphoid to just above the umbilicus when wider exposure is required (Volume I; Hanasono; Shokrollahi). - Landmarks: ligament of Treitz (start point), run jejunum distally ~20–40 cm to identify segment with longest arcades (common selection 20–40 cm distal); mark flap length on mesentery and place a marking stitch at the proximal bowel end to preserve isoperistaltic orientation. - Plan recipient vessel exposure first in the neck (typical arteries: superior thyroid, facial, lingual; veins: branches or trunk of internal jugular, external jugular) and confirm proximity of artery/vein to one another because jejunal donor vessels will be close together. 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - There are no skin perforators to identify — vascular anatomy is intramesenteric. Identify the optimal jejunal vascular arcade by transillumination/backlighting of the mesentery (sterile fiber-optic light or headlight) and choose the jejunal branch whose position and pedicle length best match the distance from the cervical defect to the recipient vessels. - Mark the bowel segment and outline the fan-shaped mesentery to be harvested. Create windows in the mesentery adjacent to proposed bowel ends for traction (Penrose loop/peritoneal windows described) and plan the mesenteric fan with apex at the pedicle. 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Mesenteric dissection: score mesentery fan on both sides; ligate crossing mesenteric vessels sequentially with 2–0/3–0 or 4–0 silk ties (small bites to avoid bunching shortens pedicle); meticulous control of mesenteric veins is mandatory—these veins are friable; clamp‑divide and ligate crossing vessels. - Clean pedicle: dissect peritoneum/fat/lymphatics off the pedicle origin for approximately 1–2 cm to expose artery and vein; separate artery and vein over ~1 cm to facilitate microvascular anastomosis. - Bowel division: clamp proximally, empty bowel manually, divide bowel ends with stapler (GIA 90 or 100 commonly used) or hand‑sew; leave the jejunal segment perfusing on pedicle until last steps; irrigation and removal of staple lines/mucous before inset. - Pedicle division: place silk tie (2–0) around pedicle artery (and vein) then divide; record ischemia time. Jejunum tolerates ~2–2.5 hours of warm ischemia (cooling strategies described but usually avoided as ischemia kept <2 hours). - Transfer: protect conduit and mesentery when passing into chest/neck — use plastic bag/chest tube technique for substernal or retrocardiac routes to prevent traction on arcades. - Inset sequence options: - Common approach: perform proximal pharyngeal (or esophageal) anastomosis first (often opened antimesenteric border 2–3 cm to accommodate size mismatch), then microvascular anastomosis, then assess perfusion (color, pulsation of arcade, peristalsis) and complete distal anastomosis. Alternatively perform microanastomosis first to shorten ischemia. - Microvascular anastomosis: arterial end-to-end to selected cervical recipient artery or internal mammary (for substernal route); venous anastomosis end-to-side to internal jugular or end-to-end to suitable branch. Expect artery diameter ~1.5–2.5 mm and vein ~2.0–4.0 mm. - Anastomotic technique for bowel: interrupted absorbable sutures commonly 2‑0 or 3‑0 Vicryl for mucosal/full‑thickness with optional seromuscular 4‑0 PDS reinforcement; distal anastomosis often single‑layer with interrupted sutures; stapling devices may be used though some series associate stapling with higher stricture risk. 4. Donor-site closure techniques. - Reestablish intestinal continuity: hand‑sewn or stapled jejunojejunal anastomosis; place feeding jejunostomy distal to anastomosis if indicated. - Close mesenteric defect with interrupted/running sutures to prevent internal herniation. - Close fascia and skin in layers. If two surgical teams available, donor closure can be performed concurrently with neck inset to reduce anesthesia time. ## Indications and Contraindications - Indications: - Circumferential pharyngoesophageal reconstruction after total laryngopharyngectomy (primary or salvage) for hypopharyngeal/pyriform sinus/laryngeal cancers. - Thyroid cancer involving the cervical esophagus. - Benign strictures refractory to dilation (radiation‑induced strictures, caustic injury). - Nonhealing pharyngocutaneous fistula after prior surgery/radiotherapy. - Supercharged jejunal flap indicated for total esophageal reconstruction when gastric pull‑up is not possible (e.g., prior/required gastrectomy, prior gastric surgery, prior radiation to stomach, failed gastric pull‑up). - Typical conduit/segment lengths: single-arcade jejunal segment commonly 15–20 cm; pharyngoesophageal defects often ≤10 cm (plan accordingly) (Hanasono; Volume I; Shokrollahi). - Contraindications: - Absolute/relative: chronic intestinal inflammatory disease (Crohn disease), uncontrolled ascites, or medical conditions that preclude a prolonged abdominal operation. - Relative: multiple prior abdominal surgeries (adhesions), severely limited pulmonary reserve, significant hypercoagulable disorder without appropriate workup/management. - Vascular disease of mesenteric vessels is uncommon but consider mesenteric angiography if suspected. ## Postoperative Care - Monitoring schedule/method: - Continuous flap monitoring in specialized unit with experienced nursing; implantable Doppler probe commonly placed on the arterial pedicle for continuous monitoring (note: implantable Doppler may not detect isolated venous thrombosis). - Many centers exteriorize a small monitoring "buoy" jejunal segment based on two terminal arcade vessels sutured to skin for visual assessment and Doppler access (removed at bedside before discharge). - Clinical checks: color, peristalsis, capillary refill, audible peristalsis; monitor frequently in first 48–72 hours (hourly initially per institutional protocol). - Warming/physiologic management: avoid hypothermia intra-/post‑op; underbody warming during case; avoid vasopressors if possible; maintain adequate hydration and urine output; DVT prophylaxis with sequential compression devices and subcutaneous enoxaparin; aspirin for 5 days may be used in patients with atherosclerotic disease. - Positioning/splinting: neck kept neutral (or slightly flexed for distal anastomosis) to minimize tension and kinking of pedicle; avoid circumferential tracheostomy ties or tapes that could compress pedicle. - Drains: place neck drains away from anastomosis and vessels; avoid drain tips contacting jejunal conduit. - Mobilization: routine early mobilization per general postoperative care; chest tubes/pleural management as required for substernal/thoracic passage. - Nutrition/feeding/analgesia: - Begin tube feeds via jejunostomy when bowel sounds return (often POD1–2 for jejunostomy feeding). - Radiographic swallow/barium study timing: for non‑irradiated patients typically POD6–8 (Volume I); for previously irradiated patients POD8–12 (Volume I). Hanasono reports 7–14 days based on context. - If no leak on swallow study, remove feeding tube and start clear liquids advancing to diet as tolerated. - If leak identified: NPO, gastric/enteric feeding via IR-placed gastric tube or maintain jejunostomy feeding, repeat swallow study after 6–8 weeks; leaks with neck infection require wide incision and drainage and possible additional reconstruction. - Return-to-OR thresholds and time windows: - Immediate re‑exploration is indicated for clinical signs of vascular compromise (sudden color change, loss of Doppler signal, tense hematoma, absent arterial signal), particularly in the early postoperative days when thrombosis most commonly occurs. Jejunal flaps have limited ischemic tolerance (approx 2–2.5 hours warm); early salvage attempts should be rapid because late thrombosis associated with infection/leak has poor salvage rates (Volume I; Hanasono). ## Complications (rates & management) - Flap success and major outcomes: - Overall free jejunal flap success reported ~91%–100% in series (Volume I). - Donor‑site abdominal complication rate reported ~4.5% in a 20‑year review (Razdan et al.) (Volume I). - Specific complications and frequencies (as reported): - Pharyngoesophageal fistula (proximal anastomosis): reported 5%–18% (more common after prior radiation) (Volume I). - Management: most small fistulas close with local wound care; infected/large fistulas require wide incision and drainage and may require surgical closure or secondary flap coverage. - Stricture (typically distal esophageal anastomosis): reported 7.5%–14%. - Management: first‑line endoscopic dilation; refractory strictures may require resection and reanastomosis or excision of redundant segment. - Pedicle thrombosis: occurs most commonly in first few postoperative days; late thrombosis can occur with leaks/infection. Jejunal grafts have poor ischemic tolerance — early re‑exploration may be attempted but salvage rates are low; many patients will require a second flap for reconstruction (Volume I; Hanasono). - Abdominal donor‑site complications: ileus, bowel obstruction, cellulitis, wound dehiscence (overall abdominal complication ~4.5%) (Volume I). - Management algorithms: - Suspected arterial or venous occlusion: immediate return to OR for exploration, remove hematoma, revise or re‑do microvascular anastomosis, thrombectomy if present. Time to re‑establish flow should be minimized given poor ischemic tolerance (~2 hours). - Leak with infection: prompt incision, drainage, broad-spectrum antibiotics, local wound care; consider reoperation for closure and vascularized tissue coverage if persistent. - Venous congestion without clear vessel thrombosis: urgent exploration is preferred; leeching is not a primary salvage strategy for jejunal free flaps in the referenced texts and has limited effectiveness given conduit anatomy and high metabolic demand. - Stricture: serial dilations; surgical revision for refractory cases. - Donor complications: manage with standard abdominal surgical care (NPO, bowel rest, return to OR for obstruction or dehiscence as indicated). ## Key Clinical Pearls - Plan recipient vessels and expose them before harvesting the jejunum — the location of cervical vessels determines flap design and reduces ischemia time (Volume I). - Mark the proximal end of the jejunal loop to ensure isoperistaltic inset (maintain orientation to optimize function) (Hanasono; Shokrollahi). - Transilluminate the mesentery (fiber‑optic/backlighting) to identify the ideal arcade and pedicle; pick the jejunal branch whose position and pedicle length minimize kinking and stretch when routed to the neck (multiple sources). - Keep ischemia time short — jejunum tolerates ~2–2.5 hours warm ischemia; organize a two‑team approach and perform microanastomosis promptly (Volume I; Hanasono). - Anticipate size mismatch at the proximal pharyngeal anastomosis — widen the jejunal proximal lumen by an antimesenteric incision ~2–3 cm or fold/double the jejunum, and reinforce with seromuscular sutures if needed (Volume I; Hanasono). - Handle the mesenteric vein with extreme care — it is friable; dissect pedicle cleanly for ~1–2 cm and separate artery/vein ~1 cm to facilitate safe microanastomosis (Hanasono; Volume I; Shokrollahi). - For total esophageal reconstruction or when additional reach is required, consider supercharging (planned division of selected mesenteric branches with augmentation by microvascular anastomosis) and use substernal routing with internal mammary recipient vessels to reduce tension on arcades (Hanasono). - Use a small exteriorized jejunal monitoring segment (buoy) or an implantable arterial Doppler — both provide early warning though venous thrombosis detection remains limited; be prepared for early re‑exploration if compromise suspected (Hanasono; Shokrollahi).