Micro Surgery in Reconstructive Surgery

Each passing decade brings newer techniques to provide solutions to certain complex and intricate problems, which had remained as Challenge in the past. Microsurgery has proved a “Panacea” for a large number of surgical problems, for which there were no alternatives earlier like Replantation of Amputated part to the body. It has been made possible to transfer a large block of live and functional tissue from one part of the body to another part using Microsurgery . A number of surgically inaccessible tissues have been made accessible by the fineness of Microsurgery and magnification. Since late 70’s, microsurgical techniques have stormed its utilization in almost all Surgical Specialties, benefiting millions of patients and Medical Practitioners all over the world.

What is “Microsurgery”? Is it a separate Surgical discipline or another Surgical hoax, which will have its time related natural death?

Microsurgery is a methodology, wherein; high power optical magnification through surgical ancillary like an Operating Microscope is being used. In the field of Reconstructive Plastic Surgery, advantages and revolutions brought about by microsurgical techniques are innumerable and un-parallel. Neuro-vascular transfer of a functioning muscle in cases of pre / post ganglionic Brachial Plexus traction injuries, post traumatic /excision loss of skeletal muscle or Volkmann’s Ischaemic Contracture and dynamic reanimation of facial paralysis, are a few of most significant contributions in last two decades.

Developments in this high precision technique were made possible by finer surgical instruments and sophisticated Operating Microscopes.

Microsurgery has progressed from: “*Amazement* to Advancement to Refinement ”

A) Replantation of Amputated Parts:

It was a great Amazement, when a few reports of successful replantation of amputated parts appeared in Medical Journals and News Papers in early 70’s. Replantation of an Amputated Part has become a standard microsurgical procedure and a large number of parts have been replanted back to the body.

What is the Protocol for Replantation Procedure?

Parts like Scalp, Ear, Nose, Digits, Extremities, Phallus etc., which are amputated with a relatively sharp instrument or a machine without any crushing or traction effect and which are not grossly contaminated with life threatening infections, are most appropriate subjects for replantation.

The amputated part should be cleaned with an antibiotic and saline solution immediately and kept in a clean plastic bag. Thereafter, the plastic bag is sealed and kept in an ice container for a cold ischaemia. If the part is kept directly on the ice, it gets macerated and may not remain suitable for Replantation. General condition of the patient and that of the amputation stump is carefully assessed for suitability for Replantation, before starting the procedure. Conditions prohibiting prolonged anesthesia or excessive blood loss during the Accident may be a relative contra-indications for Surgery of Replantation.

I prefer to dissect the amputated part first, after the arrival of the part to the Operating Room, while the patient is being worked up for pre-anesthetic checks. It takes about two to four hours to debride and dissect the amputated part, which should always be done by the Senior Surgeon himself in following manner:

1. Thorough wound debridement.
2. Identification and dissection of one / two veins.
3. Identification and dissection of Peripheral / Digital Nerves.
4. Identification of various tendons in case of Extremities / Digits.
5. Shortening of the bone for a proper Osteo – Synthesis.

After satisfying with above steps, the Amputated Part is irrigated with Hartmann’s solution and thereafter is wrapped in a sterile surgical towel and subjected to cold ischaemia. Prior to the dissection of the recipient site, the patient is suitably resuscitated and anaesthetized. The dissection is carried out in a similar order without a tourniquet; however, a tourniquet may be applied but kept un-inflated. In cases of proximal and major amputations, it is recommended to irrigate blood vessels continuously with a solution of saline + heparin + streptokinase. Having satisfied with suitability of the recipient site and the amputated part for replantation, the surgical procedure is undertaken as follows:

1. Bony fixation using either External Fixater or K-wires.
2. Repair of Extensor tendons and tagging stitches to skin.
3. Anastomosis of one or two arteries.
4. Anastomosis of veins. (Two Veins of adequate size.)
5. Co-aptation of motor / sensory nerves.
6. Repair of flexor tendons.
7. Loose closure of skin or skin graft if under tension.
8. Fasciotomy of skin and deep fascia in the amputated part in cases of proximal amputation and replantation, to avoid development of tight compartment compression syndrome following muscle edema and venous engorgement.Ideally speaking, the replantation of an amputated part should be carried out within 6 – 8 hours after the amputation, but under certain physiological conditions, a replantation may be carried out as late as thirty hours. Distal amputations with a proper cold ischaemia, can be successfully replanted up to 24 – 30 hours, however, a proximal amputation or a subtotal amputation with a relative warm ischaemia may be impractical even after 4 – 6 hours. The amount of muscle mass in the amputated part is an extremely important factor, compromising immediate and delayed results in proximal replantation. The patient may develop Acute Renal failure or a Shocked Lung Syndrome (ARDS), following a Proximal or a Major replantation, due to metabolites products of disintegrated muscles. It may also lead to electrolyte imbalance and liver failure.There are reports, wherein the amputated digits were kept in deep freeze and were replanted one by one, over a period of 3 – 4 days.
   

   Delayed Proximal Replantation of Arm After 40 Hours.

   How Safe Are They?

   1) Mr. Gupta, a young Engineer, had an Industrial accident on 30.5.95 at around 10.30 AM at Bhopal (about 800 miles away from Bombay), wherein he had a total amputation of his right arm. An attempted replantation was carried out by the orthopedic surgeon, but realizing extensive nature of the injury and failure of replantation, the patient was shifted to Bombay, at around 4.00 PM on 31.5.95 in a condition of shock and peripheral circulatory failure.

   His limb was rigid with Rigor Mortis and distal 1/2 of forearm, wrist, palm and fingers were turning black and mummified. No pulsation was felt at the elbow or wrist, nor there were any capillary bleeding on finger pinprick. An urgent DSA was performed, which confirmed complete arterial block at the subclavian artery and downwards. Microsurgical exploration was performed under general anesthesia, wherein it was noted that entire length of the brachial artery was completely thrombosed and contused due to trauma. TO RE-VASCULARIZE THE LIMB, a long saphenous vein graft was used between the subclavian artery and the brachial artery. It was around 2.00 AM on 1.6.95, that complete Revascularization of the limb could be accomplished, 40 hours after total amputation. The color of the forearm, wrist, palm and fingers gradually started turning pink and there was a brisk capillary bleeding from all fingers on needle prick. After waiting for poisonous venous effluent to be washed out of the circulation, remaining process of replantation of the arm was completed by around 4.00 A.M. and am very happy to inform that the patient has recovered completely with a fully surviving limb. It is a rare surgical feat to replant a proximal major amputation of the arm successfully, after 40 hours. Even at best of Medical Centers in the world, rarely such delayed re-plantations are undertaken. The Patient did not develop any systemic complications nor had any major wound sepsis.

   2) Ms. Naaz, A young girl of 20 years, had her left arm amputated following an automobile accident, at around 2.00 PM on 3.6.95 at Pen (Raigarh Dist. Maharashtra). She was rushed to the nearby hospital, but was very bluntly told that replantation at such a high level is not possible anywhere in the country. However, her relatives contacted me and She was admitted to the Bombay Hospital on 3.6.95. For replantation of the limb. The operation of Replantation of the arm was started along with an orthopedic surgeon at around 11.40 P.M. on 3.6.95 and was successfully completed by around 8.30 AM on 4.6.95. Vein grafts were interposed between the brachial artery and two vena comitants, while two superficial veins could be anastomosed primarily. In this patient also, the distal amputated limb had developed Rigor Mortis, as there was no circulation of blood for more than 14 hours. She is also doing fine and her limb has survived fully.

   Both these patients have received intensive postoperative care to avoid development of renal failure due to myo-globinurea, DIC, ARDS and septicemia and were subjected to Hyperbaric Oxygen therapy from 2nd postoperative day onwards. Both these patients have made an extraordinary progress and have been discharged from the hospital after 5-6 weeks respectively.

   Both these patients have undergone revision of external fixation and bone grafting for non-union at the osteosynthesis site. Both the patients have started signs of re-innervation of muscles of the forearm and may require some operations in future to improve the hand function.

   Multiple digit Replantation, although looks very exciting, consumes long operating time (an average of 5 – 8 hours per digit) and the final functional result may not be acceptable in all digits. I give an absolute priority to replantation of scalp, hand, phallus, thumb, index and middle finger. In selected patients like children, young and adults, professionals or where tips of fingers are extremely useful as in typists or computer operators, all efforts are made to replant even the most terminal part of each and every digit.

   In situations, where the proximal stump of the amputated part is not suited for replantation, the amputated part may be re-attached to other part of the body using Microvascular anastomosis with other sparable blood vessels. (“Entopic Replantation”)

   1. It may be interesting to note that the youngest patient in the world literature in whom a digital replantation was performed is a neonate, whose little finger was amputated while delivering her through LSCS, within hours the finger was replanted.
   2. There are many other interesting incidents wherein four teams were working simultaneously for bilateral double amputations of both upper extremities.
   3. The accused party had to be bribed heavily to inform whereabouts of the amputated phallus, which was chopped off due to infidelity and thrown into a sanitary tank.
   4. The hand of one side had been replanted on to the forearm of opposite side as salvage procedure, with reasonable and acceptable functional and aesthetic results.

   With natural and scientific progress in techniques of microsurgical tissue transfer and better understanding of growth and functional potential of transplanted tissues, we have entered an era of refinements. Along with a definite viability of the transplanted tissue, we have assured good functional results and a natural growth. Basic principles of Reconstructive surgery are:

   Replace the Missing Tissue with a Similar Tissue

   “Rob Peter to Pay Paul, (When Peter Can Afford it)”

   Following are a few remarkable advances in Microsurgery:

   A) Vascularized Bone Grafts:

   It is well documented that a conventional bone graft is a dead piece of bone, which gets is replaced gradually by creeping substitution from the adjoining bone, whenever and wherever it is being used. The healing of a bone defect, whether small or big, entirely depends upon regenerating power of the recipient bone.

   Vascularized bone graft is a live piece of bone with intact endosteal and periosteal blood supply. With micro-vascular anastomosis of the vascular pedicle to a major recipient vessel, the transplanted segment of the bone behaves like a denervated segmental fracture, which heals by osteoblastic activity at both ends. The medullary cavity gets unified and continuous and the grafted bone acquires the size and the strength matching to the recipient bone.

   Radioisotope bone scan is considered to be a definite test for vascularity and osteoblastic activities of the graft, which becomes positive within 24 – 48 hours. The utility of Vascularized bone grafts in clinical practice is unlimited, bringing in new philosophy of reconstruction for a variety of difficult bone defects. Conditions benefited most are congenital pseudo-arthrosis, limb salvage following large bone tumor excision or hypoplasia / Aplasia of the Ramus of the mandible, or Diaphyseal segment of long bones. Use of Vascularized fibular graft to re-vascularize the head of the femur, following avascular necrosis of the head, has been a new promising concept, which may be a substitute to a total hip replacement as more physiologic approach. Transfer of a Vascularized hyaline cartilage in Vascularized total joint transfers have already surpassed silastic joint replacement in small joints of hand.

   Being able to maintain growth at the epiphyses, it has proved to be a good procedure for temporo-mandibular joint Ankylosis with or without hypoplasia, wherein Hemi-joint or head of the fibula has been used. Similar principle has been applied to radial club hand, wherein attempts are being made to construct the lower radio-ulnar-carpel joint by epiphyses transfer.

   B) Free Functioning Muscle Transfer (F.F.M.T.):

   Improved understanding of the process of motor and sensory re-innervation of a striated muscle, following neuro-vascular microsurgical transfer have encouraged a free functional live muscle transfer (FFMT) procedure. Conditions benefited most are:

   1. Brachial Plexus injuries.
   2. Major and proximal nerve injuries of long standing.
   3. Volkmann’s ischaemic contracture.
   4. Soft tissue tumor excisions involving important muscles. and
   5. Facial paralysis (developmental or acquired.)

   Muscles most commonly used are Gracilis, Latissimus Dorsi, Serratus anterior and/or Pectoralis minor. All these muscle have a long and constant dominant vascular pedicle, a rich network of motor neural supply and least functional deficit following transfer. In children, inner diameter of the dominant vascular pedicle could be as minute as 0.3 mm. Shorter the ischaemia time of the transferred muscle is, better are functional return of motor power. It has been well documented that, if the muscle ischaemia time is less than 50 minutes during the transfer, functional power may become as strong as Grade IV. Functional muscle transfer is never to be considered as first choice in acute facial or brachial plexus paralysis, but has a definite place in cases of long standing, even up to 20 years.

   i) Facial Paralysis:

   Dynamic replacement of the mimetic muscles of the face, with synchronized movements of both normal and paralyzed sides, have been made possible by microsurgical Cross Face Nerve Grafts (CFNG), followed by Functional Muscle Transfer (FFMT), using either Gracilis or pectoralis minor muscles. The nerve from the normal side controls movements of the transferred muscle, thereby a synchronized smile is assured.

   ii) Brachial Plexus Injury: Secondary Reconstruction

   Pre-ganglionic root avulsion injuries of brachial plexus are considered to be completely irreparable. The paralyzed limb is doomed either for uselessness or an amputation. Micro neural redistribution of remaining intact roots of the plexus and / or utilization of sparable adjoining motor nerves like Accessory spinal nerve, Dorsal branch of C-4 root, motor branches of the Inter-costal nerves (T-3 to T-9) and ipsi or contra-lateral lateral pectoral nerves, offer reasonable functional recovery in most of the these plexus injuries. Use of contra-lateral C-7 Root for neurotization the plexus with or without functional muscle transfer has also been demonstrated. Following neural redistribution work and based on the recovery in muscle power, either an adjacent or a distant functional live muscle transfer is considered. A combination of latissimus dorsi muscle and / or Gracilis with adductor longus muscle gives a reasonable stability to the shoulder joint. Gracilis muscle is used for providing flexion / extension of the elbow, wrist and finger joints in selected cases.

   As functional rehabilitation with FFMT is neither based on local muscle nor on original nerve supply, there is no time limit for performing these procedures, however results are expected to be better in younger age group.

   iii) Re-Vaxscularization of Damaged Myocardium:

   In recent years, a functional latissimus dorsi muscle has been used for re-vascularization of a severely damaged myocardium, wherein a coronary bypass surgery may not be possible or advocated. The transferred latissimus dorsi muscle is reconditioned to act and to contract like a myocardium with the help of a pace maker, thus making an artificial biological heart.

   iv) Extensive Soft Tissue/Muscle Mass Loss:

   In situations like post-traumatic soft tissue loss involving either flexor or extensor group of muscles, or following a wide tumor excisions or in neuro-vascular insufficiency like Volkmann’s ischaemic contracture, a free functional muscle transfer has provided a new hope for good functional rehabilitation.

   Microsurgical free functional tissue transfers have opened up a new chapter and revolutionized Reconstructive Surgery. It has added one very powerful tool in the armamentarium of Plastic and Reconstructive Surgeons.

   Microsurgery has scaled a real height in a relatively short span of time. It has got an extremely vast clinical field and a promising future. Soon we may be able to microsurgical procedure through a Laparoscope for problems of infertility.

   Dr. Ashok K. Gupta
   Honorary Plastic and Microsurgeon.
   Bombay Hospital and Medical Resch. Centre.
   Bombay Suite No. 16, II floor.
   Laud Mansion, 21 M. Karve Road,
   Bombay – 400 004

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