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Clinical Surgery PDF

830 Pages·2008·98.26 MB·English
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694 Part 5 Specialist Surgery Once a sore has developed it is graded according to Pressure sores depth as follows: Pressure sores (decubitus ulcers or bed sores) are a erythema; common source of referral to the plastic surgical team. blister; They are due to prolonged unrelieved pressure over bony full-thickness skin loss into subcutaneous tissue; prominences and are common in patients who are bed- muscle breakdown; ridden or have restrictive casts or appliances and in those bone/joint involvement. who have large insensate areas. Sites Aetiology The site of the sore depends on the position the patient has If tissue pressure is greater than perfusion pressure, then been lying in. the blood supply to the tissue will be compromised and ischaemia with eventual necrosis occurs. Muscle is more Common susceptible to ischaemia than skin. A cone-shaped area of Sacral: from lying supine. tissue breakdown results, with its apex at the skin surface Ischial: from sitting, particularly in wheelchair-bound and its base overlying the bony prominence. The size of patients. the resultant pressure sore is proportional to the pressure Trochanteric: from lying on one side. exerted and its duration. Malleolar: from tight-fitting lower-limb plaster casts. Predisposing factors include the following. Heel: from lying supine. • Infection of the pressure sore can increase its depth. • Shearing forces lead to degloving of the subcutaneous Rare tissues, impairing their blood supply. • Occipital: lying supine, particularly in neurosurgical • Excessive moisture worsens the situation by macerat- patients. ing or eroding the skin. If this is due to faecal or urinary • Ears: lying on one side or tight-fitting bandages. incontinence, there is the added risk of infection. • Elbow. • Malnutrition, anaemia and immunosuppression, from • Scapula. concomitant illness or pharmacotherapy, not only predis- pose to pressure sores but also impair healing once the Management ulcer is established. Unfortunately, these factors are com- mon in debilitated individuals. Prevention is the best treatment and so Waterlow • Insensitivity, caused by peripheral or central nervous scores should be recorded in debilitated or bedridden system damage, allows sores to develop unnoticed from patients and appropriate preventive measures instituted minor trauma. Infection can also go undetected until the in those deemed at risk. Once a pressure sore is estab- sore reaches a considerable size. lished, treatment first addresses general factors, then relieves pressure and then involves specific management of the ulcer. Risk assessment and grading The Waterlow score was established to predict those pati- General factors ents most likely to develop pressure sores so that prevent- ive measures can be taken. It involves scoring the patient • Nutrition: malnutrition and hypoproteinaemia should on the following factors: be addressed. The patient should be considered for naso- body mass index; gastric or parenteral feeding if oral intake is insufficient or age; not possible. sex; • Anaemia should be assessed and corrected with dietary continence; supplements or transfusion according to severity. mobility; • Incontinence: catheterization is necessary for urinary nutrition; incontinence. If faecal incontinence is causing recurrent skin changes; infection or considerable deterioration of the pressure adverse wound healing factors; sore, faecal diversion should be considered. neurological deficit; • Infection should be assessed with regular swabs or surgical interventions; tissue biopsy. Appropriate antibiotic therapy should be drugs. instituted and surgical debridement may be necessary. Plastic and Reconstructive Surgery Chapter 42 695 Examples include gluteus maximus flap for sacral or Relief of pressure ischial pressure sores and tensor fascia lata flap for • Turning is vital to eliminate prolonged pressure. trochanteric sores. Occasionally, it is possible to provide • Specific beds are available to eliminate continued local- sensation by the use of innervated flaps, e.g. tensor fascia ized pressure and decrease shearing forces. These include lata flap incorporating the lateral femoral cutaneous low air loss mattresses, Clinitron bed (fluidized by warm nerve. Postoperatively, it is important to avoid pressure air), Pegasus bed (alternating pressure) and Nimbus bed on the flap for 3-4 weeks. (dynamic floatation). Since recurrence of pressure sores is common and pro- • Padding of pressure areas with specific appliances can gressively more difficult to treat, prevention is vital in prevent sores developing and progressing. These include these patients. heel pads, horseshoe head rings and a variety of pressure- relieving cushions for wheelchairs. Lower limb trauma surgery Dressings Lower limb trauma encompasses a wide range of injuries. It has been famously quoted that you can put anything on As well as fracture management the integrity of vessels, a pressure sore, except the patient. A variety of dressings nerves and soft tissues must be addressed. In most plastic are available. These range from antisloughing dressings surgery units a lower limb trauma team exists. This (to remove cellular debris) to foam-padded dressings (to includes orthopaedic and plastic surgeons, occupational protect areas at risk). In a clean pressure sore or following therapists and physiotherapists, as well as pain manage- surgical debridement, the vacuum-assisted closure (VAC) ment and prosthetic services. system can be used. This is a sponge dressing which is made to measure and placed snugly into the cavity of the Anatomy sore. Via a sealed tubing system it is connected to a free- standing vacuum device. An airtight seal is created with an Compartments and muscles (Table 42.4) occlusive dressing and negative pressure is then exerted over the wound. This removes oedema and wound The tibia and fibula are the bones of the lower leg. The effluent, which delays healing, as well as reducing the tibia bears 85% of the weight and lies medially. It is bound bacterial load. It is thought to actually increase local blood to the laterally lying fibula by the interosseous membrane. flow to the wound, although the exact mechanisms of this The lower leg is enclosed in deep fascia like a stocking. are unclear. Its main use in pressure sore management is This is a continuation of the popliteal fascia. It encloses to reduce the size of the wound, which it does by encour- the calf and lateral lower leg, attaching to the anterior and aging granulation and wound contraction. posterior borders of the tibia. Anterior and posterior Specific management Table 42.4 Compartments and muscles of the lower limb. Firstly, the pressure sore needs to be accurately assessed. Anterior compartment (dorsiflexes the foot) Microbiological evaluation should be obtained with Extensor hallucis longus wound swabs or tissue biopsies. The presence of more Extensor digitorum longus than 100,000 organisms per gram of tissue is usually Tibialis anterior indicative of infection and appropriate antibiotics should Peroneus tertius be instituted. The size and extent of the wound should be Lateral compartment (everts the foot) examined. This involves probing any cavity and obtaining Peroneus longus radiographs of the underlying bone to detect osteomyel- Peroneus brevis itis. Contrast studies are useful to delineate sinus tracts leading away from the ulcer. Posterior compartment (plantar flexes the foot) Superficial The aims of surgical intervention are: Gastrocnemius • thorough debridement of the ulcer, all necrotic tissue Soleus and the underlying bursa; Planaris • resection of the underlying bone, which is often Deep unhealthy or frankly osteomyelitic; Flexor hallucis longus • coverage of the defect with well-vascularized tissue. Flexor digitorum longus In general, large regional skin or myocutaneous flaps are Tibialis posterior used as rotation or advancement flaps to cover the defect. 696 Part 5 Specialist Surgery Definition Rare • Occipital: tying supine, particularly in neurosurgical Pressure sores: ulcers over bony prominences caused patients by prolonged unrelieved pressure leading to ischaemic • Ears: lying on one side or tight-fitting bandages necrosis • Elbow • Scapula Local predisposing factors • Infection Management • Shearing forces Preventive measures instituted in those deemed at risk based • Excessive moisture on Waterlow score • Malnutrition, anaemia and immunosuppression • Insensitivity General • Nutrition: make sure patient is fed (enterally or Risk assessment and grading parenteralfy) Waterlow score • Anaemia: correct Risk assessment score based on following: • Incontinence: catheter for urine, consider diversion for • Body mass index faeces • Age • Infection: treat appropriately • Sex • Continence Pressure • Mobility • Turn patient frequently • Nutrition • Use special beds: • Skin changes (a) Clinitron (fluidized by warm air) • Adverse wound healing factors (b) Pegasus (alternating pressure) • Neurological deficit (c) Nimbus (dynamic floatation). • Surgical interventions • Padding: heel pads, horseshoe head rings, pressure- • Drugs relieving cushions • Dressings: antisloughing dressings, foam padded Grading (according to depth) dressings, VAC system • Erythema • Blister Specific management • Full-thickness skin loss into subcutaneous tissue Accurate assessment • Muscle breakdown • Swabs/tissue biopsies for microbiology (> 100,000 • Bone/joint involvement organisms/g of tissue means infection is present) • Measure size and extent of wound by probing any cavity and obtaining radiographs CCoommmonmon lying supine Aims of surgery particularly in wheelchair-bound • Debridement of the ulcer • Resection of the underlying bone lying on-one side • Cover defect with well-vascularized tissue: probably a tight-fitting lower-limb plaster casts myocutaneous flap • Recurrence is common intermuscular septa are attached to the peroneal surface ment lies between the anterior and posterior intermuscu- of the fibula and these, with the tibia and interosseous lar septa. The posterior flexor compartment is commonly membrane, divide the lower leg into three compartments called the calf. It is separated from the peroneal compart- (Fig. 42.18). The anterior extensor compartment is bounded ment by the posterior intermuscular septum and from the medially by the subcutaneous border of the tibia, laterally anterior compartment by the interosseous membrane. Its by the anterior intermuscular septum and behind by the muscles lie in two groups, superficial and deep, subdivid- interosseous membrane. The lateral peroneal compart- ing it into two compartments. Plastic and Reconstructive Surgery Chapter 42 697 Figure 42.18 Cross-section of the right lower leg. The course and functions of these nerves are shown in Arteries Figs 42.19 & 42.20. • Anterior tibial artery: supplies the anterior (extensor) compartment of the lower leg. It starts at the bifurcation of Lower limb injuries the popliteal artery under the fibrous arch of the soleus muscle. It lies medial to the neck of the fibula. It passes Pretibial lacerations forwards above the upper border of the interosseous membrane and then descends in front of it. It lies between These are flap lacerations of the thin skin overlying the the malleoli at the ankle joint and there becomes the subcutaneous tibial border. They are common in the dorsalis pedis artery, which can be easily palpated. It elderly population, who tend to have thin fragile skin, and passes under the extensor retinacula with the deep per- are often the result of minimal trauma. oneal nerve lying laterally. Any haematoma should be evacuated to avoid pressure • Posterior tibial artery: supplies the posterior (flexor) necrosis of the overlying skin. Broad-based skin flaps with compartment of the lower leg. It also starts at the bifurca- a proximally based pedicle may be viable and can be relaid tion of the popliteal artery under the fibrous arch of and secured with Steri-strips. Thin distally based flaps will soleus. It runs deep to gastrocnemius and soleus on the have unreliable blood flow and are often not viable. This tibialis posterior, flexor digitorum longus and tibia. At the type of injury should be debrided and resurfaced with a ankle joint it lies behind the medial malleolus where it can split-thickness skin graft. This may be feasible under local be easily palpated. Here it is between the tendon of flexor anaesthetic. digitorum longus and the tibial nerve. • Peroneal artery: supplies the lateral compartment of the Open fractures lower leg. It is a branch of the posterior tibial artery arising just after it commences. It runs medial to the fibula These injuries are often the result of high-velocity trauma. between tibialis posterior and flexor hallucis longus. Concomitant injury to other sites, including the head, chest and abdomen, are common. Therefore the initial management of these patients should be thorough assess- Nerves ment as per the ATLS protocol. The lower limb should About a hand's breadth above the knee the sciatic nerve then be carefully evaluated once the patient is stable. divides into the tibial and common peroneal nerves. The common peroneal nerve divides under peroneus longus Evaluation into the deep and superficial peroneal nerves. The nerve • Vascularity: palpate the posterior tibial and dorsalis of the anterior compartment of the lower leg is the deep pedis arteries. If they cannot be felt manually, use hand- peroneal. The nerve to the lateral compartment is the held Doppler ultrasound. If there is any uncertainty or if superficial peroneal and the nerve to the posterior com- revascularization may be needed, then angiography of the partment is the tibial nerve. lower limb is indicated. 698 Part 5 Specialist Surgery Figure 42.19 Course and distribution of the tibial nerve. • Bony injury. X-ray of the fracture should provide a clear structures have been damaged and determine how the description of fracture site, displacement and stability. soft-tissue defect can be reconstructed. • Soft-tissue damage: the size and site of soft-tissue dam- • Nerves: motor and sensory function of each nerve must age are important. They give a clue as to what underlying be assessed and documented (Table 42.5). Plastic and Reconstructive Surgery Chapter 42 699 Figure 42.20 Course and distribution of the superficial and deep peroneal nerves. Classification only is it useful for aiding management plans but it can also There are a variety of classifications available for describing be a rough guide to prognosis. For example, approximately open fractures of the lower limb. The Gustillo classification 4% of grade IIIC injuries often proceed to amputation and is commonly used for open tibial injuries (Table 42.6). Not approximately 70% of grade IIIB injuries require flap cover. 700 Part 5 Specialist Surgery Table 42.5 Assessment of motor and sensory function of The patient is then transferred to theatre and further lower limb nerves. assessment of the injury is performed under general anaesthesia. The specific management is then dictated by Tibial nerve the nature of the injury. As a rule all grossly contaminated Motor and devitalized skin, muscle and free bone fragments are Inability to plantar flex the foot at the ankle indicates removed during this procedure and copious irrigation is proximal lesions and paralysis of the gastrocnemius and performed. If possible the fracture is also stabilized at this soleus muscles time, with external or internal fixation as appropriate. If Sensory vascular injury is present it must be repaired as a priority. Loss of sensation over the lower posterior calf, lateral foot and Often no attempt is made to close the wound at this stage little toe (sural nerve) and it is left open and packed with suitable dressings. Quite often the zone of injury in these wounds is not Deep peroneal nerve demarcated on presentation. Tissues of marginal viability Motor may become non-viable. Therefore re-exploration and The patient has footdrop with inability to dorsiflex the foot further debridement may be necessary 48-72 h later. and great toe due to paralysis of the extensor hallucis Once the viability of the remaining tissue is beyond doubt longus and tibialis anterior and the fracture has been appropriately fixed, the method Sensory of soft-tissue reconstruction can be addressed. Loss of sensation over the first web space Soft-tissue reconstruction Superficial peroneal nerve This is dictated by the site and extent of the soft-tissue loss. Motor • Split skin grafting. This is appropriate for defects with a Inability to evert the foot at the ankle due to paralysis of suitably clean and graftable bed. Therefore it is usually peroneus longus and peroneus brevis precluded if the fracture is exposed, as the periosteum will have been stripped. Sensory • Local muscle flaps. These are ideal to cover small areas of Loss of sensation over anterolateral calf and second and third exposed fracture site. The medial head of gastrocnemius web spaces is most commonly used. The muscle can be split in its midline through a longitudinal posterior calf incision. The medial half is then detached from its insertion into Table 42.6 Gustillo classification of open tibial fractures. the Achilles tendon and tunnelled through to fill the defect. A split skin graft is then placed over the exposed Grade Tissue injury muscle. • Local fasciocutaneous flaps. Again these are useful for I Clean wound < 1 cm smaller defects. They can also be used to cover fracture II Wound 1 -5 cm but no significant tissue disruption sites. The donor site can be closed directly if small or split MIA Wound > 5 cm but adequate soft-tissue coverage skin grafted. with local tissues IIIB Extensive soft-tissue loss, contamination, periosteal • Free tissue transfer. This is necessary for larger defects stripping and a variety of muscles can be employed. Microvascular IIIC Arterial injury requiring repair anastomosis is necessary usually to the posterior or anter- ior tibial vessels. Bone reconstruction Management The problem of bony loss can also be addressed. Once the patient has been appropriately resuscitated, • Small defects can be bridged with cancellous bone wound swabs should be taken and broad-spectrum anti- grafts as long as there is a well-vascularized bed. It is biotics started. Tetanus prophylaxis should be assessed advisable to wait 6-8 weeks after injury before doing this, and immunoglobulin given if required. The wound as non-vascularized bone is susceptible to infection. should be dressed with a non-absorbent dressing and • Larger defects require vascularized bone as free tissue Betadine-soaked gauze and then wrapped and splinted. transfer. Manipulation of fractures at this stage should only be • Intermediate-sized defects can be treated using the performed if they are impinging on the vascularity of the Ilizarov technique. An external fixator is used that encour- lower lee. ages distraction osteogenesis. Plastic and Reconstructive Surgery Chapter 42 701 compromise and the enclosed muscles become ischaemic. Degloving injury Prolonged ischaemia will result in necrosis and, ultim- This is an avulsion of the skin, with or without underlying ately, fibrosis of the muscles and surrounding soft-tissue tissues from deeper planes. Degloving injuries are com- structures. Compartment syndrome in the lower limb monly the result of road traffic accidents. Those that result is defined as intercompartmental pressures exceeding from being run over by a bus or truck are most serious, as 35 mmHg. These can be measured at the bedside using a the broad tyres of these vehicles distribute the shearing special manometer. forces over a wide area, which can result in circumferential Clinically, the patient complains of pain out of propor- degloving of the entire skin and subcutaneous tissue of the tion to the injury and this is exacerbated by stretching of leg. the involved compartment muscles. As pressure increases The plane through which the skin is detached can be there is loss of sensation in the distribution of the involved superficial, involving just skin and subcutaneous fat. nerves and ultimately the local pulses are lost, although However it can also incorporate the deep fascia. The skin the latter is not necessary to make the diagnosis. The may tear, creating a flap, or there may be no detectable 'four Ps' of compartment syndrome that aid diagnosis skin breach, just bruising and swelling. The perforator comprise: blood supply from the muscles to the skin and subcutan- • pain; eous fat is destroyed. So too is the vascular network in the • paraesthesia; superficial fascia. This results in ischaemic necrosis of the • paralysis; detached skin. There are two types of degloving injury. • pulselessness. • Type I: open wound due to degloving of the skin and Treatment involves immediate decompression. This is subcutaneous fat with a narrow zone of undermined performed under general anaesthesia by incising all four tissue around the periphery of the wound. muscle compartments (fasciotomy). The wounds are • Type II: extensive undermining of soft tissues with no left open, allowing swelling to occur unrestricted, and or a relatively small open wound. The initial assessment of dressed with appropriate sterile dressings. The wounds are these wounds frequently underestimates the extent of closed at a later time once the acute episode has resolved. damage, as most of the leg appears normal, apart from the Sometimes this is not possible directly and split skin grafts presence of tyre marks and patches of ecchymosis. Unless are used. treated early, the full extent of soft-tissue loss is apparent only a few days later, and gives rise to systemic sepsis due Surgery for congenital deformities to necrosis of large areas of subcutaneous fat underneath the normal-looking skin. Fluoroscein injected intra- Congenital head and neck problems venously circulates only to viable tissue and is a method of defining all non-viable tissue (that which does not Embryology fluoresce) at an early stage. The clinical picture initially is less dramatic than The embryology of the head and neck is complicated. The expected, but the skin does not show blanching on pres- normal skull develops from a membranous capsule that sure or capillary refill and skin edges do not bleed. All non- encloses a growing brain and then ossifies, whereas the viable skin and underlying fat should be excised and the base undergoes mainly cartilaginous ossification. In the defect resurfaced with a split-thickness skin graft. There third week of embryonic life these processes develop can be a delay in graft application, allowing a 'second look' around the primitive mouth (Fig. 42.21). at 48 h and further debridement if necessary. The non- • The frontonasal process projects down from the skull. viable areas excised can be used as donor sites if the defect The nostrils develop from two olfactory pits within it. This requiring grafting is extensive. This should be performed projection finally forms the nose, nasal septum, nostrils, early. philtrum (central upper lip depression) and the premaxilla. • The two maxillary processes, one on each side, come to the midline and fuse with the frontonasal process. These Compartment syndrome form the cheeks, upper lip (excluding the philtrum), Oedema is a sequela of trauma. If this occurs in a limited upper jaw and palate (excluding the premaxilla). anatomical space, such as one of the four compartments • The two mandibular processes meet in the midline to of the lower limb, tissue pressure will rise. As tissue pres- form the mandible. sure rises, the pressure on and within the local venous sys- Abnormalities of this complex fusion process result in tem also rises. Arterial resistance subsequently increases one of the most common congenital deformities, cleft lip and inflow is reduced. If left untreated there is vascular and palate. Table 42.7 Embryology of the branchial arches. Cartilage/bone Soft tissue (endoderm Arch structure Cranial nerve Muscles (mesoderm) and ectoderm) Artery Abnormality First Mandible, maxilla, V, including Muscles of mastication, mylohyoid, Anterior two-thirds Maxillary Cleft lip and palate, incus, malleus chorda anterior belly digastric, tensor tongue glands and preauricular skin tags, tympani palati and tensor tympani mucous membranes Treacher-Collins syndrome, Pierre Robin syndrome Second* Stapes, styloid process, VII Muscles of facial expression, stylohyoid ligament, buccinator, platysma, lesser horn and superior stapedius, stylohyoid, part hyoid bone posterior belly of digastric Third Greater horn and caudal IX Stylopharyngeus, upper pharyngeal Carotid part of hyoid constrictors Fourth Thyroid cartilage X: superior Lower pharyngeal constrictors, Right: subclavian laryngeal levator paliti Left: aortic arch Sixth Cricoid, epiglottic and X: recurrent Intrinsic laryngeal/pharyngeal muscles Pulmonary arteries This explains why the arytenoid cartilages laryngeal and ductus recurrent laryngeal nerve arteriosus on left is looped under the ductus arteriosus on the left * The second arch grows down over the other arches, leaving a space known as a cervical sinus. This normally disappears but if it persists it may form a branchial cyst or sinus (filled with glairy fluid saturated with cholesterol crystals) or a branchial fistula. The fistula extends from the anterior border of the junction of lower and middle thirds of the sternocleidomastoid to between the external and internal carotid arteries and then opens into the tonsillar fossa. Plastic and Reconstructive Surgery Chapter 42 703 Cleft lip and palate Cleft lip and/or palate is one of the most common congenital abnormalities, occurring in approximately 1 in 700 live births. There is a definite genetic influence. Subsequent siblings of an affected child have a risk of developing a cleft of between 1 in 10 and 1 in 50. When both parents have a cleft the risk of involvement of their offspring is 1 in 2 to 1 in 3. Cleft lip and palate may occur separately or together and may be unilateral or bilateral: • cleft lip and palate (50%) (Fig. 42.23a); • cleft lip alone (25%) (Fig. 42.23b); • cleft palate alone (25%). Submucous cleft palate is one of the mildest forms. The Figure 42.21 Fetal head (ventral aspect) showing the embry- palatal mucosa is intact but the muscular layers are not; it ological development of the face. should be suspected in a child with a bifid uvula. It may not become apparent until the child has difficulty in phonation. Around the same time a series of branchial arches (or pharyngeal arches) develop, eventually fusing in the Management midline (Table 42.7). The external depressions between • Multidisciplinary teams are necessary to treat this these arches are known as the ectodermal branchial clefts, complex problem. Members include plastic, ENT and whereas the internal grooves are known as the endoder- maxillofacial or orthodontic surgeons, speech therapists, mal branchial pouches (Table 42.8). nutritionists, paediatricians and psychologists. • Feeding can be difficult with cleft palates and the baby will have difficulty in suckling but not swallowing. Breast-feeding may not be possible. Special teats have been developed to help bottle-feeding. • Surgical repair is carried out in stages. Timing varies greatly between surgeons but the trend is now towards early (neonatal) repair of the lip and repair of the palate at 6 months. • Orthodontic treatment is carried out in parallel with other procedures. Emphasis is placed on the early phase of permanent dentition. Bone grafting to the alveolar cleft defect at 10-12 years of age will allow teeth to migrate into the correct position. Table 42.8 Embryology of the branchial clefts and branchial pouches. Pouch Structure (endoderm + mesoderm) Cleft Structure (endoderm) First Middle ear, mastoid antrum, tympanic membrane First External auditory meatus, tympanic membrane Second Tympanic cavity, palatine tonsils Second Third Thymus gland, inferior parathyroid (III) Third Thymus gland descends, pulling parathyroid III below parathyroid IV Fourth Superior parathyroid (IV) Fourth Attached to the thyroid gland, therefore prevents parathyroid IV going below parathyroid III Fifth Ultimobranchial body, which develops into parafollicular (C) cells of thyroid gland

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