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Thumb reconstruction by microvascular methods

  1. Thumb Reconstruction by Microvascular Methods Dr Suiyibangbe M.Ch Plastic and Reconstructive Surgery
  2. Introduction The thumb plays a crucial role in proper functioning of the hand. It is unimportant to humans only during the first 3 months of life. At only 9 months of age, the thumb begins to function as it will in adulthood. Thumb opposition, unique to primates, allows the human hand to perform power grip and precision handling. In fact, the thumb itself is responsible for 40% to 50% of the overall function of the hand.
  3. Cont... Reconstruction of the thumb remains a major surgical challenge because of its unique "position" in the hand's structure. To provide a painless thumb with good stability, sensibility, and mobility to oppose the adjacent fingers. The first priority is pain follow by stability, and only then are sensibility and mobility considered. Stability concerns both the skeleton and the skin cover; the necessity of a distal vascularized bone for avoidance of any long term resorption.
  4. Cont... • Microsurgical toe transfer is an excellent option for thumb reconstruction because it meets all of the requirements for providing good hand function. • The toe, after all, is a digit itself and therefore is similar anatomically to the thumb. • Its skeletal structure consists of two phalanges motored by extensor and flexor tendons. • It is covered with durable glabrous skin that is innervated by digital nerves. • It provides all of the necessary components of good thumb function and excellent appearance of the reconstructed thumb. • With proper operative planning and meticulous technique, donor site morbidity and functional compromise can be minimized.
  5. • Figure 173-1 Key functional movements of the thumb: A, opposition; B, three-point pinch; C, key pinch; D, cylinder grasp.
  6. History • In 1960, Jacobson and Suarez catapulted reconstructive surgery to a new level with their report on anastomosis of small blood vessels, giving birth to the era of modern microsurgery. • Subsequently, Buncke successfully performed toe to thumb transfer on a rhesus monkey, proving the feasibility of this procedure in primates. • Toe to thumb transplantation was first reported in 1891 by Nicolandi using a pedicled technique. • In 1969, Cobbett performed the first microsurgical thumb reconstruction in humans with a transferred great toe. • Subsequent refinements in toe to thumb transfer and in microsurgical technique have provided the hand surgeon with an invaluable tool to restore hand function.
  7. CAMPBELL-REID CLASSIFICATION FOR THUMB AMPUTATION Group 1:- Amputation distal to the metacarpophalangeal joint, leaving an adequate stump. Group 2:- Amputation of the thumb distal to or through the metacarpophalangeal joint, leaving a stump of inadequate length. Group 3:- Amputation through the metacarpal, with preservation of some functioning thenar muscles. Group 4:- Amputation at or near the carpometacarpal joint.
  8. • Figure 173-11 Anatomy of the dorsalis pedis artery and its distal branches to the great toe. (From Serafin D: Atlas of Microsurgical Composite Tissue Transplantation. Philadelphia, WB Saunders, 1996:91.)
  9. • Figure 173-12 A and B, Anatomic variations and their rates of occurrence in the dorsalis pedis artery and its distal branches. DCA, distal communicating artery; DDA, dorsal digital artery; DPA, dorsalis pedis artery; FDMA, first dorsal metatarsal artery; FPMA, first plantar metatarsal artery; PDA, plantar digital artery; TML, transverse metatarsal ligament. (From May JW, Chait LA, Cohen BE, et al: Free neurovascular flap from the first web of the foot in hand reconstruction. J Hand Surg [Br] 1977;2: 389. Reproduced with permission from The British Society for Surgery of the Hand.)
  10. • Figure 173-25 Schematic representation of tissue that can be harvested in part or in total for partial toe flap reconstruction. (From Serafin D: Atlas of Microsurgical Composite Tissue Transplantation. Philadelphia, WB Saunders, 1996:142.)
  11. THE PROBLEM • The evolution of modern society has brought with it new challenges for the hand surgeon. • As the world's population continues to grow at alarming rates, and as medicine finds new ways to allow newborns with severe birth defects to survive, the number and scope of congenital and acquired non traumatic thumb anomalies have increased. • Progressive industrialization throughout the world has increased the number of traumatic hand injuries.
  12. Causes of Thumb Loss A. Congenital (partial or total) absence.  Dietary deficiency  Fetal neurogenic injury.  Maternal viral infection, drugs (thalidomide )  Reduced oxygen tension B. Loss due to malignant disease, such as melanoma. C. Loss due to trauma. including industrial, nonindustrial, and environmental insults.
  13. Implications • The degree of functional compromise associated with thumb loss depends on the level of amputation. • Thumb loss can be described as total or subtotal. • In cases of total thumb loss, little or no metacarpal remains; in subtotal loss, some amount of skeletal length of the thumb is preserved. • Subtotal loss has been further categorized. 1. Morrison subdivides subtotal loss into proximal subtotal and distal subtotal loss, depending on the relationship of the amputation level to the MCP joint of the thumb. 2. Strickland and Kleinman use a scheme that divides subtotal loss into thirds (proximal, middle, and distal). 3. Amputation levels have been divided by Leung into four "types“ that he thinks are useful for decision-making in second-toe transfer.
  14. Level of Amputation From Morrison W, O'Brien BM, MacLeod AM: Experience with thumb reconstruction. Br J Hand Surg 1984;9:224.) A, Amputation level as classified by Kleinman and Strickland. B, This classification can be useful in choosing reconstructive options after thumb loss
  15. • Figure 173-4 Schematic depiction of four types of thumb loss. (From Leung P: Thumb reconstruction using second-toe transfer. Hand Clin 1985;1:286.)
  16. ANALYSIS OF THE PATIENT WITH THUMB LOSS • In the evaluation of patients being considered for microvascular reconstruction of the thumb, • History, physical examination:- toe transfer must pay particular attention to the affected thumb or recipient site of the operation, assessment of the length, mobility, gross sensibility, vascularity, and soft tissue coverage. • Tests of hand function and anatomy to ensure for a well-planned reconstruction. • Plain radiographs demonstrate the skeletal extent of the thumb's deficiency.
  17. Cont... • Vascular anatomy of the lower extremity must also be assessed preoperatively. In addition to physical examination, duplex ultrasonography or angiography can be helpful. • Planning of a proper thumb reconstruction also requires assessment of preoperative hand function to determine what functional needs the transferred toe has to supply. • Thumb range of motion including flexion, extension, opposition, and both palmar and radial abduction and adduction must be assessed. • Sensibility can be assessed by subjective measurement of light touch and two-point discrimination and by Semmes-Weinstein monofilament testing.
  18. Preoperative Consultation • The surgeon must carefully assess the patient in consultation to determine whether the patient is an appropriate candidate for microvascular thumb reconstruction. • The procedure places significant physical demands on the patient and requires intensive postoperative rehabilitation. • Stop smoking and tobacco free for at least 1 month before toe transfer. For confirmation of abstinence from tobacco use, a urine nicotine level can be checked within 24 hours of surgery. If the result is positive, surgery is postponed until the patient is able to cease use of tobacco products.
  19. TREATMENT Goals • In designing the proper treatment for thumb reconstruction, the needs of the patient are a primary consideration. patient's occupation, hand dominance, and overall health are important. • Microvascular thumb reconstruction places significant physiologic, psychological, and socioeconomic demands on the patient. • A patient undergoing this procedure must be able to modify daily activities to allow the tissues time to heal. • Patients who are unable or unwilling to comply with intensive hand therapy should not be considered for toe to hand transfer because this procedure cannot succeed without proper postoperative treatment.
  20. Great-Toe to Thumb Transfer • The great toe has historically been the workhorse donor for microsurgical toe to thumb transfer. • The great toe can be used in its entirety, or it can be used partially as either a wraparound flap or trimmed flap. • The maximum circumference of the contralateral thumb is also measured, usually just distal to the IP joint. • This number is compared with the maximum diameter of the great toe.
  21. Cont... • Toe to thumb transfer is performed under general anesthesia. • The anesthesiologist must diligently maintain the patient's body temperature to minimize vasoconstriction. • The patient's blood pressure should be maintained at an adequate level to maintain perfusion to the toe flap. • In general, a systolic pressure of at least 110 mm Hg is desirable. • Blood pressure should be managed with intravenous fluid when possible, and vasoconstrictive agents should be avoided. • Dissection of both the hand and foot is done under tourniquet control and loupe magnification.
  22. Cont... • Ideally, two separate surgical teams operate simultaneously to minimize operative time. • The goals of the hand dissection include careful incision planning; identification of the anatomy of the recipient hand; and preparation of the skeletal, vascular, and neural structures of the recipient hand for toe transfer. • In general, an incision that designs proximally based radial and ulnar flaps is preferred. • The position of the radial artery should be identified by palpation or Doppler examination and then marked on the skin. It provides proper orientation of incision
  23. • Figure 173-7 A and B, Representative incision markings on recipient hands.
  24. Cont... • After elevation of the skin flaps, the digital nerves are identified and dissected free from surrounding soft tissues. • Nerve ends are then tagged with 8-0 nylon suture for later identification. • Tendons are next addressed if a dynamic toe transfer is planned (static toe transfers, such as the wraparound procedure, do not require tendon repairs). • Next, the donor arterial supply must be addressed. The artery is located by extending the dorsal incision proximally toward the anatomic snuffbox, over the dorsal web space of the thumb. • Once it is identified, the artery is dissected free from surrounding soft tissues and marked with a vessel loop. • When an adequate vein is identified, it is dissected in a fashion similar to dissection of the artery and marked with a vessel loop for later identification.
  25. Cont.. • If the toe is to be attached to the proximal phalanx of the thumb or to the thumb metacarpal, the recipient structure will have to be prepared for osteosynthesis. • Once it is identified, the distal end of the bone is dissected subperiosteally. An osteotomy is then performed with an oscillating saw. • If the toe is to be transferred to the proximal phalanx of the recipient thumb, the osteotomy is made in a straight transverse fashion. • If the recipient bone is the thumb metacarpal, however, it is preferred to make the metatarsal osteotomy with a slight angle in a proximal dorsal to distal plantar direction. • At the completion of the hand dissection, the tourniquet is deflated to allow reperfusion of the upper extremity, and hemostasis is achieved. The wounds are then dressed with saline-moistened dressings until the donor toe is ready for transfer.
  26. • Figure 173-8 Completed dissection of the recipient hand. Tendons, vessels, and nerves are tagged for easy identification.
  27. TOE DISSECTION • Toe dissection is ideally carried out by a second operative team simultaneously with the hand dissection. • The course of the dorsalis pedis artery and dorsal superficial veins of the foot is marked out on the dorsal skin of the foot preoperatively by a combination of palpation and Doppler examination. • Assessment of venous anatomy can be assisted by dependent positioning of the extremity and the use of a "venous tourniquet" with a tourniquet pressure of approximately 80 mmHg. • The incision for the toe harvest is also designed. • In general, an incision that develops dorsal and plantar flaps, with a dorsal proximal extension for vessel dissection, is used. This provides good access for dissection and develops flaps that are complementary to the radial and ulnar flaps of the hand.
  28. • Figure 173-9 Incisional markings for great-toe harvest.
  29. Cont... • After gravity exsanguination of the lower extremity and inflation of the tourniquet, incisions are made. • Dissection is performed with the assistance of loupe magnification. • Skin flaps are elevated laterally and medially on the dorsum of the foot to expose the underlying structures. Where it is possible, small sensory nerves are preserved. • Next, the superficial saphenous venous system is examined, and one or more veins of adequate size and length are identified as the donor vein.
  30. • Figure 173-10 A and B, Intraoperative and schematic representations of great-toe dissection showing the saphenous vein. (From May JW, Chait LA, Cohen BE, et al: Free neurovascular flap from the first web of the foot in hand reconstruction. J Hand Surg [Br] 1977;2:391. Reproduced with permission from The British Society for Surgery of the Hand.)
  31. Cont... • Next, the dorsalis pedis artery is identified proximally in the dissection. This structure is dissected proximally to provide adequate length for anastomosis to the recipient artery in the hand. • During this dissection, the extensor hallucis brevis muscle is divided to allow adequate exposure of the vessel • The final structure on the dorsum of the foot that must be prepared is the extensor hallucis longus tendon and flexor pollicis longus tendon in the hand.
  32. Cont... • In great-toe transfers, the branch to the second toe is divided just distal to the branch point of the first dorsal metatarsal artery. • Once the arterial and venous systems have been dissected, they can be tagged with vessel loops for later identification. • When re-establishment of dorsal sensory function of the transferred toe is desired, the deep peroneal nerve, which runs adjacent to the dorsalis pedis artery, can be included in the flap. • With the neurovascular and tendinous dissections completed, attention is now turned to the skeletal support of the toe. • The osteotomy is performed with an oscillating saw.
  33. • Figure 173-13 Pattern for metatarsal osteotomy of the donor toe. This permits osteosynthesis to the proximal metacarpal in 60 degrees of extension, which transforms a primary extensor joint into a flexor joint. (From Serafin D: Atlas of Microsurgical Composite Tissue Transplantation. Philadelphia, WB Saunders, 1996:600.)
  34. Cont... • With the toe dissection completed, the lower extremity tourniquet is deflated, allowing reperfusion of the toe. • Because of arterial spasm resulting from dissection, the donor toe might remain pale for up to 20 to 30 minutes after release of the tourniquet. • Spasm can be minimized by topical application of compounds such as papaverine or concentrated lidocaine (20%) to the vessels. • Once reperfusion to the donor toe is established, it should be allowed to perfuse for approximately 20 minutes before completion of the harvest and transfer to the hand.
  35. Great Toe transfer • Figure 173-14 Explanted great toe before transfer. EHB, extensor hallucis brevis; EHL, extensor hallucis longus; FHL, flexor hallucis longus. (Courtesy of Neil Ford Jones, MD.) • Figure 173-15 Schematic of method of pin fixation of the MCP joint after toe transfer. (From May JW, Bartlett SP: Great toe-to-hand free tissue transfer for thumb reconstruction. Hand Clin 1985;1:274.)
  36. Cont... • With the recipient site prepared and the toe dissected, transfer of the toe to the hand is next undertaken. • The donor artery and then the vein are divided proximally and flushed with lactated Ringer solution containing 10 units/mL of heparin. • The transfer is begun with reconstruction of the skeletal framework. • The joint should be pinned in a position of slight flexion. • Many techniques exist for osteosynthesis, including the use of K-wires, rigid fixation systems, and interosseous wiring. • It is preferable to use rigid plate and screw fixation for osteosynthesis because of its strength and allowance of early active range of motion in the reconstructed thumb.
  37. • Figure 173-16 The transferred toe after vascular clamp removal. Note the healthy color of the flap.
  38. Cont... • With the skeletal reconstruction complete, repair of soft tissues is undertaken. It is preferable to repair tendinous structures first, then the nerves, followed by the artery and finally the vein. • If there is any question about the patency of any of the vascular anastomoses revision should be performed immediately. • The microsurgical axiom "if you think it is probably OK, it isn't" applies in this as in all other microsurgical settings.
  39. Cont... • Donor and recipient skin flaps are brought into approximation and trimmed as necessary. • It is preferable to use a single-layer, tension-free closure with interrupted monofilament suture. • In children, absorbable suture, such as chromic gut, should be used to eliminate the need for later suture removal. • In situations in which flaps cannot be closed without undue tension, a skin graft is used for cover, provided that all vital structures, such as nerves, blood vessels, and tendons, are covered by healthy vascularized soft tissue. • After placement of the usual sterile dressings, the extremity is placed into a well-padded thumb spica splint with the tip of the toe flap visible for postoperative monitoring.
  40. • Figure 173-17 The wounds have been closed. Skin grafts are used where needed to avoid undue tension in the closure.
  41. Wraparound Flap • Because the great toe is larger than the normal thumb, various modifications of great-toe transfer for thumb reconstruction have been developed to design a better size match. • The wraparound technique was first described by Morrison et al in 1980. • In this procedure, only the soft tissue and nail of the great toe are transferred to the hand, without the metatarsal or proximal phalanx of the great toe. • An iliac crest bone graft, if required, provides skeletal support for the reconstructed thumb. • Indicated when complete skin avulsion in which the skeleton and tendons remain intact reconstruction of amputations distal to the MCP joint
  42. Cont...  The advantages of this flap include – better size match with the opposite normal thumb; – provision of sensibility, – length, and stability to the reconstructed thumb; and – preservation of a portion of the great Toe.  The disadvantages to this flap. – Because this is an essentially static transfer when the use of an iliac crest bone graft is required, it is useful only for thumb loss distal to the MCP joint. – If it were used more proximally, the limitation of motion in the thumb would be unacceptable. – Another disadvantage of this flap is its lack of potential for growth because of the absence of an epiphysis. – Resorption of the bone graft is another potential problem.
  43. FLAP DISSECTION • Because the ulnar vessels of the thumb tend to be dominant, the ipsilateral great toe is usually chosen for wraparound great-toe transfer. • The arterial supply to the flap tends to run in a medial direction as it courses distally on the foot, which corresponds to the course of the radial artery in the hand. • Careful incisional planning is required for successful wraparound toe transfer. • The circumference of the contralateral normal thumb must be measured at its base and at the widest portion of the thumb pulp between the tip of the digit and the IP joint. • The donor toe is measured in a similar fashion and the difference between corresponding measurements in the toe and thumb is determined. • Markings are made to design a flap that is based proximally and employs the skin of the dorsal, lateral, and plantar skin of the great toe. • At the completion of the dissection, a tongue of proximally based skin and subcutaneous tissue remains on the medial side of the great toe and is used for closure of the donor site. The width of this tongue corresponds to the difference between the circumference of the great toe and the circumference of the thumb as measured.
  44. • Figure 173-19 Incision markings on the foot for wraparound great- toe transfer. (Courtesy of Neil Jones, MD.)
  45. DONOR SITE CLOSURE • A number of techniques have been described for closure of the donor site after wraparound great- toe transfer. • The whole of the remaining skeletal framework can be preserved and the soft tissues reconstructed by a combination of the medial tongue of skin and soft tissue left behind by toe harvest a cross-toe flap from the plantar surface of the second toe. • Alternatively, the remaining skeleton can be shortened to allow donor site closure with only the medial great-toe skin flap.
  46. • Figure 173-20 If the medial fold of the nail is carefully reconstructed, appearance is greatly improved. (Courtesy of Neil Jones, MD.) • Figure 173-21 Degloved thumb with bone graft in place before completion of reconstruction with toe transfer. (From Urbaniak JR: Other microvascular reconstruction of the thumb. In Green DP, ed: Operative Hand Surgery. New York,Churchill Livingstone, 1988:1319.)
  47. • Figure 173-27 Long-term follow-up photographs after wraparound procedure (A) and trimmed great-toe procedure (B and C). (Courtesy of Neil Jones, MD.)
  48. Trimmed great-toe flap • The trimmed great-toe flap was first described in the late 1980s. • This technique has the advantage of the wraparound great- toe flap, namely, better size match of the contralateral thumb, but avoids the disadvantage of lack of mobility and growth potential. • The trimmed toe flap is harvested with both the proximal and distal phalanges. • The circumferences of the soft tissues and the bone are reduced to match the circumference of the contralateral normal thumb. • With this technique, joints and epiphyses are preserved. • The indications for this technique include those for the whole great-toe and wraparound techniques where better size match of the contralateral normal thumb is desired.
  49. • Figure 173-22 Marking for osteotomy of the donor toe for trimmed toe technique. A, Dorsal view. (From Upton J, Mutimer K: A modification of the great-toe transfer for thumb reconstruction. Plast Reconstr Surg 1988;82:535-539.) B, Lateral view of osteotomies. (From Wei FC, Chen HC, Chuang CC, Noordhoff M: Reconstruction of a thumb with a trimmed-toe transfer technique. Plast Reconstr Surg 1988;82:506-513.)
  50. FLAP DISSECTION • Markings for the trimmed great-toe technique are similar to those for the wraparound technique. • The medial proximally based skin flap is elevated off of the underlying periosteum, with care being taken to preserve the medial neurovascular structures of the toe. • A proximally based flap consisting of periosteum and the medial collateral ligament of the IP joint of the toe is then elevated off of the underlying bone structures. • The circumference of the phalanges is reduced by making a longitudinal osteotomy in the sagittal plane. • The toe is harvested and inset in a fashion similar to that of the whole great-toe technique. • Skin closure and management of the nail plate and eponychial fold are similar to those of the wraparound great-toe flap. The donor site closure is identical to that for the wraparound flap.
  51. Second-Toe to Thumb Transfer • Transfer of the second toe to the hand was first described in China in 1973. • This technique carries with it multiple advantages that make it an excellent option for microsurgical thumb reconstruction. • The second toe's minimal donor site impact, excellent appearance, and superb function after transfer into the thumb position make it the preferred digit for toe to thumb transfer. • The use of the second toe minimizes donor site problems associated with toe transfer, which can be both functionally and socially significant. • After transfer of the second toe, the overall contour of the foot is nearly normal. absence of this toe is hardly noticeable on casual observation. • Available skeletal length of the donor toe.
  52. • Figure 173-24 Dissected second toe before transfer. (Courtesy of Neil Jones, MD.)
  53. Disadvantages • Small size of the donor. This makes for a thumb that is narrower and weaker, and therefore potentially less functional, than one reconstructed with a great toe. • lack of soft tissue available for coverage of interosseous muscles and bone when a long length of metatarsal is used.
  54. • Figure 173-26 Thumb extension (A) and opposition (B) after microvascular toe to thumb transfer.
  55. • Figure 173-18 Appearance of the foot after harvest of the great toe (A) and second toe (B). C, Note the minimal impact on appearance of the foot after second-toe harvest. (Courtesy of Neil Jones, MD.)
  56. POSTOPERATIVE MANAGEMENT • Critical to the success of microvascular thumb reconstruction is proper postoperative care. • Thumb is placed into a splint that provides immobilization without constricting the thumb. • Circumferentially wrapped dressings of gauze or other materials should not be used on the inner layers of the splint to avoid constriction. • The splint should leave the tip of the thumb visible for postoperative monitoring of thumb perfusion. • The donor lower extremity is placed into a posterior splint. • Both extremities are elevated during the first 2 weeks to minimize postoperative edema and venous congestion. • Flap monitoring during the first 48 hours after surgery must be frequent.
  57. Cont... • Many methods have been devised to automate monitoring of the flap's vascular status postoperatively, including implantable Doppler devices, laser flowmetry, and pulse oximetry. • The most reliable method of evaluation is hourly visual inspection of the flap for color and quality of capillary refill during the first 2 postoperative days. • if flap perfusion is in question, urgent return to the operating room with exploration of the anastomosis is imperative for flap salvage. • The first 3 to 5 postoperative days are spent in a warm room to minimize vasoconstriction, and adequate hydration of the patient is ensured. • Anticoagulation of low-molecularweight dextran and aspirin are given.
  58. Cont... • Intravenous antibiotics, which are administered intraoperatively, are also given during the first 5 to 7 postoperative days. • At around postoperative day 5, the dressings on the upper extremity are changed, and a well-padded splint is reapplied. • Sutures are removed from the hand and foot on or around postoperative day 14. • If pins were used for osteosynthesis or to support another method of osteosynthesis such as interfragmentary wiring, they are removed when there is clinical and radiographic evidence of stability and healing of the bone.
  59. Rehabilitation • Requires intensive postoperative therapy to maximize the final result. • The therapy protocol must be individualized for each case but must address tendon gliding, recovery of nerve function, and management of soft tissue issues (such as edema, scarring, and joint stiffness). • Limitation on timing and aggressiveness of the therapy protocol will be dictated by skeletal stability and wound healing, which vary from case to case. • Wei has advocated a rehabilitation protocol that begins on the first postoperative day with flap observation and psychological support provided by the hand therapist and early passive mobilization of the reconstructed thumb beginning on postoperative day 4. • Active range-of-motion exercise is then started during the fifth postoperative week. • Recovery of sensibility after toe transfer is a somewhat slow process that tends to reach a maximum at about 2 years postoperatively
  60. Complications  ACUTE COMPLICATIONS • Anesthetic complications • Infection • Bleeding • Wound healing complications • Thrombosis of microvascular anastomosis • Flap necrosis • Rupture of nerve repairs • Rupture of tendon repairs  CHRONIC COMPLICATIONS • Tendon adhesion • Joint stiffness • Flexion contracture • Poor recovery of sensibility • Delayed union or nonunion of osteosynthesis
  61. Thank you
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