Principles, Techniques and Applications in Microsurgery

The following sections are included:

• Translator’s Note

• Contents

Microsurgery is defined as a surgical technique making use of fine instruments, to perform operations under the operative magnifying glass or microscope. It is a new development in modern surgical skill, and a new means used in the process of surgical cure, and tissue and organ transplant. The scope of activities by operating under the operative magnifying glass or microscope well exceeds the limitations of human vision. The ability to identity the various normal and pathological structures is greatly increased, making surgical techniques more accurate. It can also be applied in the anastomosis of microvessels, nerves and even lymphatics. It has opened new prospects for using various surgical techniques which would not have been possible in the past. It has also developed and raised the standards of existing surgical techniques…

In the development of microsurgery, the Chinese saying, “Equipment determines Performance”, carries a practical meaning…

The following sections are included:

• Section 1 Basic Requirements in the Operative Procedures of Microsurgery

• Section 2 Techniques in the Anastomosis of Microvessels
  • Methods of Anastomosis of Microvessels
  • End-to-end Anastomosis
  • End-to-side Anastomosis (Fig. 3-2-4)

• Section 3 Precautions in the Preparation and Operation of Vascular Anastomosis
  • Dissection of blood vessels
  • Pre-operative preparations for vascular anastomosis
  • Procedures and precautions in vascular anastomosis
  • Microvessel grafts

• Section 4 Other Methods of Microvascular Anastomosis
  • Vessel ring anastomosis
  • Anastomosis using a suturing device
  • Anastomosis using tissue adhesives

The following sections are included:

• Section 1 Anatomy and Physiology of the Microvascular Structures
  • Regeneration and repair of small blood vessels after anastomosis:

• Section 2 Experimental Research on Replantation of Rabbit’s Ears
  • Method of experiment:
  • Discussion

The anaesthesia for microsurgery is more or less the same as for other surgeries. The choice is based on the site and duration of operation and the general condition of the patient. However, in some technical details, anaesthesia for microsurgery has its special considerations for the anaesthetist and the surgeon.

While carrying out tissue transplants with blood vessel anastomosis, careful consideration should be given to the patient’s general and regional conditions which include the donor and recipient areas. A careful and detailed operating plan should be set up taking into account the actual condition of these areas…

The following sections are included:

• Section 1 Applied Pharmacology of Antispasmodics
  • Vasodilators
  • Regional Vasodilators

• Section 2 Anticoagulants & their Applications
  • Heparin
  • Dextran
  • Dicoumarol
  • Aspirin
  • Magnesium sulphate
  • Streptokinase

With the continuous growth in the scope of clinical applications of microsurgery, many new topics which require continuous development and upgrading of standards have appeared. Both post-operative treatment and nursing care are experiencing the same kind of development…

To prevent complications like vasospasm, formation of thrombus and infection after vascularised tissue transplant, antispasmodic drugs, anticoagulants and antibiotics, etc., are used regularly and have definite preventive effects. However, more important are the effective measures in preparing the donor and recipient areas, for example, detailed design, gentle preparation of transplanted tissues, thorough removal of pathological tissues in the recipient area, co-ordination of the position after tissue transplant, atraumatic manipulation of blood vessel anastomosis and aseptic techniques, etc. Negligence of any of these can cause failure in the transplant…

Microsurgery has a very wide application in neurosurgery, for example, in operations involving the cerebral vessels, spinal vessels, tumours of the brain and the spine, and in operations for pain and peripheral nerves, etc. Operations on intracranial vessels include those involving the narrowing and obstruction of the cranial arteries, carvernous haemangiomas, malformation of the arteries and veins, etc. Microsurgery for brain tumour has its main application in operations for tumours at the base of the brain and the deep part of the cerebrum, for example, pituitary tumours, pineal body tumours, acoustic neuroma, sphenoidal meningioma, intra-ventricular tumours and brain stem tumours. Microsurgical procedures for pain and peripheral nerves include operations for trigeminal neuralgia, Meniere Syndrome and facial nerve lesions. Following the rapid development of microsurgery, the area of application has become wider and wider. We shall discuss some of the main areas here.

The following sections are included:

• History of Oesophageal Reconstruction

• Experimental Study on Free Vascularised Jejunal Segment Transfer

• Clinical Indications and Techniques for Autogenous Segmental Gut Transfers
  • Selection of recipient vessels
  • Positioning of the transplanted gut segment
  • Complications after segmental gut transplantation

• Post-operative Management for Segmental Gut Transplantation

• An Evaluation of Oesophageal Reconstruction using Jejunal Segments

The greater omentum is a layer of structure in the peritoneal cavity with rich blood supply, lymphatics and fats. Under normal circumstances, it does not manifest performance of any important function and is seldom noticed. Initially, it was regarded as a structure to keep the body warm and as a buffer to protect the organs in the peritoneal cavity when there were external disturbances. At the end of the 19th century, Bennet (1894) first reported a case of perforated stomach repaired with greater omentum. In 1906, Morrison discovered that the greater omentum was able to migrate towards inflammed sites, close up perforated holes, limit the infective sites and supply blood to the healing tissues. Thus it was called the ‘policeman of the peritoneal cavity’. In 1936, O’Shanghnessy transplanted the greater omentum with intact pedicle to the cardiac muscle, attempting to improve the myocardial ischaemia and obtained some success in preventing recurrence of angina. Walter in 1937 applied it in treating the more complicated cases of cardiac ischaemia. Thompson in 1945 used it to treat bronchial fistulae and obtained successful results. In 1967, Goldsmith and Santos cut of the left gastro-epiploic artery and vein from the greater omentum and freed the omentum from the greater gastric curvature and transverse colon. The right gastro-epiploic artery and vein were used as a vascular pedicle which was tailored into a bandage form according to the distribution of vascular network. It was then pulled out of the peritoneal cavity from a small incision in the abdominal muscles to reach the groin region and space between the thigh muscles. It was hoped that this would improve the stagnant lymphatic or venous return from the lower limbs, in chronic lymphatic obstruction or other diseases of circulatory impairments in the lower limbs. In 1972, Dupont et al treated a patient with a large, deep, irradiated ulcer on the chest wall with omental graft. After separating one side of the greater omentum, the other gastro-epiploic artery and vein were reserved as a vascular pedicle. It was pulled out of the peritoneal cavity from an incision on the upper abdominal wall and reached the chest wall through a subcutaneous tunnel. It was then used to cover the debrided wound in the chest wall. Subsequently, skin grafts of medium thickness were applied on the greater omentum. After the operation, all the skin grafts transplanted on the greater omentum survived and complete cure in the ulcerated area was achieved…

The following sections are included:

• Section 1 Replantation of Avulsed Scalp and Free Transplant of Scalp Flap with Vascular Anastomosis
  • Applied surgical anatomy of scalp
  • Replantation of the scalp after avulsion
  • Repair of partial scalp damage — free scalp flap transplant

• Section 2 Free Transplant of the Temporalis Fascia

• Section 3 Subaxillary Lateral Thoracic Free Flap Transplant
  • Regional anatomy
  • Indications of operation
  • Preoperative preparation
  • Operative procedures
  • Advantages and disadvantages of the subaxillary dorsothoracic flap
  • Case examples

• Section 4 Free Flap Transplant from the Groin Region
  • Anatomy of the groin flap
  • Indications for operation
  • Operative procedures
  • Post-operative management
  • Case Examples

• Section 5 Free Transplant of the Dorsalis Pedis Flap of the Foot
  • Topographic anatomy of the dorsalis Pedis flap
  • Indications, operation and pre-operative preparations
  • Operative procedures

• Section 6 Forearm Flap Transplant
  • Applied Anatomy in Microsurgery
  • Indications
  • Operative Techniques

• Section 7 Double-linked Free Flaps
  • General Concept
  • Anatomy
  • Operative Planning
  • Indications
  • Operative Procedures

In 1970, Tamai used the microsurgical technique successfully in the vascularised transplantation of the gracilis muscle in a dog. The results indicated that the muscle survived and the tissue structure and neurological function were nearly normal. Later, many surgeons used free muscles for transplantation in the reconstruction of different deficient functions, and the results were variable. With further developments in microsurgical techniques and a better understanding of blood supply to the skin, it has been found that the human skin has two types of blood supply: Type one is when there are specific cutaneous vessels, and such skin can be used for free vascularised skin flap transplantations. Examples of such type include the groin region, the dorsum of the foot, the deltopectoral region and the inferior axillary region. The other type of blood supply comes from the underlying muscle. Perforating branches pass from the muscle to the skin overlying it. Most of the areas of human skin in fact are supplied by this type of perforating arteries (Fig. 14-0-1).

Hence, while muscle transplantation is being done, its overlying skin can be harvested together with the muscle. Harii in 1976 successfully transplanted a vascularised free myocutaneous flap using the gracilis muscle and its overlying skin. This technique was later applied clinically. Since 1977 the author has been applying myocutaneous flaps using the gracilis, latissimus dorsi, and extensor brevis of the foot for the reconstruction of deficient extensor or flexor in the forearm and intrinsic muscle losses in the hand. Two to four years of follow-up indicated that the electromyelogram of the transplanted muscles was normal, and the muscle power reached grade three to four. We feel that the use of myocutaneous muscle transplant produces better results than using simple muscle transplant. This is because post-operative oedema or haematoma is much less in the myocutaneous type, and therefore functional recovery tends to be more satisfactory. The myocutaneous type of muscle transplant might eventually replace all free muscle transplant. The major description in this Chapter therefore deals with the myocutaneous type, and free muscle or tendon transfer will be discussed briefly at the end of the Chapter.

Soft tissue deficiencies causing superficial depressions and deformities have posed difficult problems for reconstructive surgery. In the past, soft tissues like fat, true skin and fat, fascia and skin, etc, have been widely used to fill up concavities and correct deformities. Clinical experience showed that these methods of free transplant might not have good long term results. The common defects of these methods of transplant are: (1) The power to resist infection is extremely low. This is particularly so in the case of superficial transplants. Even for stitch infection, the transplanted substance might get infected and subsequently undergo necrosis and rejection. (2) Large grafts very often lead to central septic necrosis and liquidation. (3) Gradual absorption by the surrounding tissues occurs after transplant. Absorption is particularly obvious for free fat transplant, sometimes one-third to half of the fat transplanted may be absorbed. (4) Fibrosis of the transplanted tissues resulting in late deformities…

The following sections are included:

• Section 1 Replantation of Limbs and Digits
  • Indications
  • Complications after Replantation

• Section 2 Free Toe Transplant for Reconstruction of the Thumb and the Finger
  • Regional Anatomy
  • Indications for Toe Transplant
  • Operative Procedures
  • Case Examples

• Section 3 Combined Toe and Dorsal Flap Transplantation
  • Regional Dissection
  • Surgical Indications
  • Operative Procedures

Rupture of the lacrimal duct is usually caused by direct trauma: simple rupture is usually produced by sharp instruments or punch wounds; complicated ruptures are usually produced by inner canthal skin avulsions. The latter type of injury is associated with inner canthal ligament rupture, and a serious disruption of inner canthal architecture. Since lacrimal duct disruption leads to obstruction of tear flow, epiphora results and this causes severe discomfort in the patient. Treatment for this condition, especially for the chronic cases, has been far from satisfactory. Nowadays, under the magnification of the operative microscope, ruptured lacrimal ducts may be identified and subsequently anastomosed. Deficiencies occur in the lacrimal ducts and reconstructions of such ducts may be carried out by using membrane transplant, and by applying the method of canalisation, the patency of these lacrimal ducts may be maintained.

The conventional method of bone grafting makes use of free bone grafts without vascularisation. This method was first utilised by Macewen in 1887 who successfully used such grafts for humeral bone reconstruction in a child. Later, Barth in 1893 and Axhauson in 1908 carried out experimental research and clinical applications of such bone grafts. Barth felt that most of the transplanted bone underwent necrosis and was later replaced by living bone. Axhauson pointed out that the cellular elements of the cortical layer became less dense, there was new bone formation in all the areas that were in direct contact with live tissues, and this new bone formation followed the newly growing vessels into the dense necrotic bone which was eventually replaced by new bony tissue. This form of bone transplant must go through the stage of necrosis followed by new bone formation. The bone graft was replaced by new bone formed from the osteoblasts (the bone graft itself worked as a scaffolding to the new bone formation). This concept has persisted until today…

The following sections are included:

• Section 1 History of Microsurgery for Peripheral Nerves

• Section 2 The Anatomy of Peripheral Nerves

• Section 3 Repairing Peripheral Nerves with Microsurgical Techniques
  • Advantages of using Microsurgical Techniques in Peripheral Nerve Repair
  • Different Types of Microsurgical Techniques in Peripheral Nerve Repair
  • Indications
  • Positioning
  • Operating Procedures
  • Post-operative Management

• Section 4 Fascicular Grafting for Peripheral Nerve Repair using Microsurgical Techniques
  • Nerve repair by pulling the cut ends together has the following obvious disadvantages:
  • Indications for Surgery
  • Anaesthesia
  • The Common Cutaneous Nerves used for Grafting
  • Operating Procedures for Fascicular Nerve Grafts
  • Post-operative Management

• Section 5 Neurolysis using Microsurgical Techniques
  • Historical Review
  • Indications
  • Anaesthesia
  • Operating Procedures

• Section 6 Vascularised Nerve Graft
  • Blood Supply to the Peripheral Nerve
  • Indications
  • Anaesthesia and Positioning
  • Operating Procedures

• Section 7 Microsurgery for the Facial Nerve
  • The Anatomy of the Facial Nerve
  • Reconstructive Operations for the Facial Nerve inside the Temporal Bone
  • Peripheral Facial Nerve Palsy and its Reconstructive Surgical Measures
  • Microsurgical Procedures in the Treatment of Facial Palsy using Free Nerve Grafts

Lymphedema is produced by continuous lymphatic obstruction which leads to fibrosis and areolar thickening in the soft tissues below the skin and around the muscle fascias. Lymphedema produces marked thickening of the skin and the forelimb. Sometimes, the skin is so much thickened that it resembles elephant skin, hence, lymphedema is also called elephantiasis…

Injury to the penis can be due to trauma like bullet wound, blast injury and avulsion or various cuts which produce complete or partial loss of the organ. Total amputation of the penis done for squamous cell carcinoma also produces complete or subtotal loss of the penis, causing severe problems in urination and sexual function. As the resulting physiological and psychological trauma to the patients are immense, a reconstruction of the penis should be performed. Apart from these indications, reconstruction is also necessary in cases of congenital penile aplasia or hypoplasia such as hermaphrodites…

The following sections are included:

• Bibliography

• Author Index

• Subject Index