Файл: NMS Surgery_booksmedicos.org.pdf

The need for radiographic assessment in patients with urologic trauma is based on the mechanism of injury, vital signs, physical examination, and urinalysis.

Blunt trauma

Patients with gross hematuria or microhematuria and a systolic blood pressure (SBP) <90 mm Hg require radiographic evaluation of the kidneys.

Patients with microhematuria who have always had an SBP <90 mm Hg do not require a radiographic evaluation unless clinical suspicion is high based on the mechanism of injury (e.g., fall from a height, direct blows, high-speed motor vehicle crashes).

All patients with penetrating trauma , regardless of the degree of hematuria, require an evaluation.

Possible radiographic tests include an IVP, CT scan of the abdomen and pelvis, cystogram, retrograde urethrogram, and renal angiography.

P.478

B Renal injuries

Classification: American Association for the Surgery of Trauma Organ Injury Scale

Contusion. There is no obvious parenchymal injury, but there may be a subcapsular hematoma.

Minor lacerations are superficial cortical disruptions that do not involve the collecting system.

Major lacerations are deep corticomedullary lacerations that do not involve the collecting system.

Deep lacerations of collecting system or injury to the renal artery or vein may be involved.

Avulsion of the renal vessels may occur, or the kidney may be shattered and destroyed.

Radiographic assessment includes:

CT scan of the abdomen and pelvis. It is the first -line test performed to rule out renal injury. Early venous phase and 10 -minute delayed images are required.

Renal arteriography is generally reserved for patients with possible vascular injuries that are not elucidated on the CT scan and may require embolization.

Treatment

Contusions, minor lacerations, and some major lacerations can be managed nonoperatively with bed rest, serial hematocrit evaluation , and hydration. Ureteral stenting may be required in cases of ongoing urinary extravasation.

Angiography and embolization can control most renal bleeding.

Major lacerations or vascular injuries usually require surgical staging and therapy.

Penetrating renal injuries usually require exploration, and in addition, they have a high risk of associated intra -abdominal injuries.

Surgical exploration includes debridement of nonviable renal tissue, closure of the collecting system, coverage of the injury with perinephric adipose tissue, and drainage of the retroperitoneum. Stents are usually not needed.

Repair of vascular injuries can frequently be problematic. Branch renal veins may be ligated, whereas arterial injuries with viable renal parenchyma require meticulous vascular repair. Prolonged ischemic time with arterial injuries usually mandates nephrectomy.

Complications of renal trauma

Post -traumatic hypertension appears to be uncommon but may occur in 5%–10% of patients and is mediated by renin owing to ischemic tissue.

Associated injuries are more common in patients with penetrating rather than blunt trauma. Right renal injuries are associated with liver trauma, and left renal injuries are associated with splenic injuries in blunt trauma. Bowel lacerations, pancreatic injury, and other vascular injuries occur with penetrating trauma. An initial identification of associated injuries with appropriate treatment will prevent many complications of renal trauma.

C Ureteral injuries

Etiology. Ureteral injuries are caused mainly by penetrating trauma or iatrogenic injury. Deceleration injuries may result in avulsion of the ureteropelvic junction, especially in children.

Radiographic assessment. The site of injury can usually be identified on IVP or CT. a. An intraoperative retrograde pyelogram can further delineate the injury.

Treatment. All ureteral injuries should be explored and repaired.

Upper and midureteral injuries are debrided, primarily repaired, drained, and stented.

Lower ureteral injuries usually require debridement, drainage, repair by ureteroneocystotomy, and stenting.

Iatrogenic crush injuries, if identified at the time of injury, can usually be managed by ureteral stenting alone.

Unrecognized injuries frequently present later as fistulas or urinomas, with fever and pain. Treatment of fistulas or obstruction may require stenting with or without percutaneous drainage. Primary open repair, after more than 3–5 days, risks renal loss.

D Bladder trauma (lower urinary tract)

Etiology. Blunt bladder trauma is frequently associated with pelvic fractures. Rupture can be extraperitoneal or intraperitoneal, depending on the location of the tear. Associated urethral injuries should always be considered as a possibility.

P.479

Evaluation. Blood at the urethral meatus, an elevated prostate gland on DRE, or a mechanism of injury possibly causing a urethral tear should prompt a retrograde urethrogram before catheterization of the bladder. A 20–24 French urethral catheter should be passed into the bladder. Drainage and oblique films are necessary with plain film cystography. A cystogram involves maximally (400–500 mL) filling the bladder to determine extravasation of contrast medium (e.g., CT or plain film ).

Treatment. Many small extraperitoneal tears heal with a urethral catheter change alone. Extraperitoneal tears complicated by rectal or urethral trauma, any intraperitoneal tears, and exploration for other reasons require closure of the laceration and placement of a Foley catheter.

E Urethral injuries

Evaluation. The examination and radiographic assessment are described earlier (Chapter 21 C 7-D 1 a). A high index of suspicion should be maintained, because passage of a urethral catheter may significantly worsen a mild urethral injury.

Treatment

All penetrating anterior urethral injuries should be explored, debrided, and repaired primarily. A urethral catheter should be left in place after repair.

Complete prostatomembranous urethral disruptions from blunt trauma require open suprapubic tube placement.

Attempts at primary repair are not warranted.

Attempts at “realignment” over a urethral catheter or with flexible cystoscopes may be indicated.

Follow-up open repair of post-traumatic strictures should occur 3–6 months after the injury.

F Penile injuries

Fracture of the erect penis caused by direct blunt trauma that significantly bends the organ can result in a tear of the tunica albuginea of the corpora cavernosa. Urethral tears are associated injuries (20%).

Physical findings include ecchymosis, swelling, and deviation of the penis.

Diagnosis can usually be made based on the patient's history and physical examination.

Treatment involves operative repair via a circumcising incision and closure of any cavernosal tear. An evaluation via a urethrogram with repair of the urethral injury may be necessary.

Penetrating penile trauma is evaluated and treated similarly to a fractured penis. All such injuries should be explored and repaired.

G Testicular trauma

Blunt trauma. The physical examination is an integral part of the evaluation. Testicular rupture is the primary injury that requires surgical repair , and testicular ultrasound is frequently beneficial when making this diagnosis. A large hematocele is an additional indication for surgical exploration.

Penetrating trauma. The physical examination and ultrasound may prove helpful. All suspected testicular or spermatic cord injuries should be explored.

Chapter 26

Plastic Surgery and Skin and Soft Tissue Surgery

Nick Tarola

John H. Moore Jr.

I Plastic Surgery

Plastic surgery as an art and science deals with the reconstruction of body parts altered by trauma, birth defects, or advanced age. It is one of the oldest fields of surgery, having first been described in 700 B.C., in India. In 1818, von Graefe used the term plastic in his monograph on nasal reconstruction; and throughout the years since then, this term has been associated with surgery that is concerned with form and function. An understanding of the skin layers and of suturing techniques is essential to plastic surgery (see Chapter 2).

A

Skin or the integumentary system , is the largest organ in the body. Three properties of skin are essential for understanding reconstruction—elasticity, extensibility, and resilience.

Elasticity keeps skin in constant tension, owing to underlying collagen fibers. The function of elasticity becomes apparent when facial wrinkles form in its absence.

Extensibility refers to the skin's ability to stretch, which can be seen on abdominal skin during pregnancy.

Resilience is noted by the skin's resistance to infection and puncture.

B

Skin grafts are segments of epidermis and dermis that have been detached from their native blood supply to be transplanted to another area of the body. A skin graft may be an autograft (i.e., from the same person), an allograft (i.e., from a genetically dissimilar individual of the same species, usually a cadaver), or a xenograft (i.e., from a different species, usually pigs) (see Chapter 24, I B 1). Cultured skin can be grown from human epidermal cells; this skin is most useful for extensively burned patients because more surface area can be covered; however, the cultured skin tends to be very thin.

Types. Skin grafts are classified according to thickness.

Split-thickness skin grafts contain the epidermis and a portion of the dermis. They are further divided into thin, medium, and thick, based on the amount of dermis included in the graft (0.010– 0.025 inch). The abdomen, buttocks, and thighs are common donor sites.

Advantages of split -thickness skin grafts include:

A large supply of donor areas

Ease of harvesting

Availability of donor site for reuse in 10–14 days

Decreased primary contracture

Coverage of large surface areas

Ability to be stored for later use

Disadvantages of split -thickness skin grafts include:

Cosmetic inferiority to full -thickness skin grafts

Decreased durability

Hyperpigmentation

Increased secondary contracture

Full -thickness skin grafts contain the epidermis and the full thickness of dermis without subcutaneous fat. They are most useful for covering defects on the face or hand that are not

P.481

amenable to coverage with a skin flap (see I C). A good match of skin color can be obtained from donor sites in the postauricular or supraclavicular areas. Preauricular grafts provide the best color match for the face. The forearm and groin can also serve as donor sites for defects below the clavicle.

Advantages of full -thickness skin grafts include:

Cosmetic superiority to split -thickness skin grafts

Decreased secondary contractures (grafts may be cut as required to fill the defect)

Increased durability

Disadvantages of full -thickness skin grafts include:

Limited donor sites

Increased primary contracture

Composite grafts are those that are formed of multiple tissues (e.g., a fingertip containing skin, subcutaneous fat, and bone or a segment of ear containing skin and cartilage). These grafts may be effective in young patients or in situations where the distal portion of the graft is less than 1 cm from the blood supply.

Grafting procedures

Split-thickness skin grafts are best obtained with specifically designed instruments rather than being taken freehand.

Methods of obtaining the graft include the following:

Knives , such as the Humby or Weck, are fitted with an adjustable roller or gauge to determine thickness. The knife is slowly advanced as cutting proceeds in a back -and - forth direction.

The drum (Reese) dermatome fixes the epidermis to the drum with glue, which allows the graft to be cut as the drum is rolled back. The cut grafts have a uniform thickness.

The electrical dermatome, such as the Brown or Padgett, has a rapidly oscillating knife and a gauge to adjust depth. Long strips of skin can be removed with this instrument.

Care of the donor site following the cessation of capillary oozing will aid in re-epithelialization.

Meshed, nonadherent gauze allows the scab to be incorporated into the dressing. In 2 days, the dressing is dry; the covering, with the incorporated scab, falls from the wound in 2 weeks.

Semipermeable membranes trap leukocyte-rich fluid to form an artificial blister, which hastens epithelialization. Patients note diminished pain at the donor site.

Care of the recipient (grafted) site (see I B 3)

Hemostasis is necessary to ensure adequate tissue contact.

When excessive wound drainage or potential infection may be a problem, the graft can be cut and a meshing device can be used to ensure adequate drainage. This technique is also useful for expanding the surface area of a graft. Epithelialization quickly occurs in the meshed interstices following graft “take.” Meshing of the graft can sometimes lead to a “cobblestone” effect in the final result of the graft. This effect can be minimized with a pressure garment (e.g., Ace bandage, Jobst garment) in the first few months after the grafting procedure.

The graft may be fixed to the recipient site by sutures or tapes. An external fixation with a “tie-over bolus” dressing (i.e., a large dressing made of gauze or cotton) may be required in areas where immobilization is difficult or where shear forces are expected. The open method, in which the graft is left exposed, may be useful for large surface areas in burn patients; daily inspection for infection is important.

Full -thickness skin grafts

Method of obtaining the graft. The grafts are “harvested” with a freehand technique using a no. 10 or no. 15 knife blade. A portion of subcutaneous fat is also harvested and must be excised carefully before grafting.

Care of the donor site involves primary skin closure in most instances. Split -thickness skin grafts may be necessary in some cases.

P.482

Care of the recipient site is similar to care in split -thickness skin grafts. Tie-over bolus dressings are frequently used.

Survival of skin grafts

Vascular recipient beds are necessary to provide nourishment for the transplant tissues.

Imbibition of plasma supports survival during the first 48 hours. Fibrin is laid down and helps to hold the graft in place.

Inosculation (vascular budding) occurs, and the graft is usually supported by a true circulation by the fourth to seventh day. Generally, a graft begins to turn pink at this time. Lymphatic connections are formed by the fifth day.

Contact of the skin graft is essential for inosculation to take place. Factors that can lead to loss of contact include:

Tension on the graft

Fluid (e.g., blood, serum, or pus) underneath the graft

Movement between the graft and its bed

Preparation of wound to be grafted

Bone denuded of periosteum, cartilage denuded of perichondrium, and exposed tendon do not support skin grafts; these areas require a flap procedure.

Infected wounds do not support skin grafts. The critical bacterial concentration appears to

be 10 5 organisms per gram of tissue, and quantitative bacterial counts are useful when determining a wound's suitability for grafting. Mechanical debridement with a scalpel and scissors is necessary to remove necrotic tissue. Frequent dressing changes with saline or dilute (0.1 strength) Dakin's solution (i.e., sodium hypochlorite) are also quite effective in debriding wounds. Once there is no further necrotic material in the wound, the use of a biologic dressing (i.e., an allograft or xenograft) helps to reduce the bacterial count.

C

Flaps are segments of skin and subcutaneous tissues that are moved from one part of the body to another, either retaining or transplanting their vascular supply, which is via a segmental artery through a perforating artery to a cutaneous artery supplying the dermal–subdermal plexus. Because of their intrinsic blood supply, flaps are useful for healing and for covering defects that require padding.

Types (Fig. 26 -1)

Skin flaps

Random flaps receive their blood supply from the dermal–subdermal plexus. These flaps lack an anatomically recognized arterial and venous system. Examples include:

Z -plasty (Fig. 26 -2)

V -Y advancement flaps

Rotation flaps (Fig. 26 -3)

Transposition flaps (Fig. 26 -4)

Axial flaps have a direct cutaneous artery and vein supplying their subdermal plexus. Therefore, the blood supply is more reliable than with random flaps, and flaps of greater length may be obtained. Axial flaps may be detached as free microvascular flaps and transplanted to other areas of the body, provided that the vessels are large enough. Examples of axial flaps include:

Forehead flaps

Groin flaps

Deltopectoral flaps

Muscle flaps provide increased blood supply to an area. Generally, they are used to cover exposed bone and are usually skin grafted. When the overlying skin and subcutaneous tissue are included,

they are called myocutaneous (musculocutaneous) flaps.

The blood supply is predictable, and the flaps can be outlined anatomically. The flaps contain muscle with a named artery, which must be identified and preserved (Fig. 26 -5).

Muscle flaps have been most useful in reconstruction of the lower extremity and in areas of poor vascularity. Myocutaneous flaps have been useful for reconstruction of tissue that has been injured by radiation.

P.483

FIGURE 26-1 Types of flaps. (Adapted from

Daniel RK, Kerrigan CL. Principles and physiology of skin flap surgery. In: McCarthy JG, ed. Plastic Surgery. Vol. 1. Philadelphia: WB Saunders; 1990:293.

)

FIGURE 26-2 Classic 60-degree angle Z-plasty.

P.484

FIGURE 26-3 A: Technique for rotation of flap. B: Rotation of a myocutaneous flap used for reconstruction of posterior thigh defect with tensor fascia lata flap.

Fasciocutaneous flaps involve the transfer of skin, subcutaneous tissue, and the underlying fascia with an anatomically distinct artery. Because there is no mobilization of underlying muscle, there is less functional debilitation. The donor site must be skin grafted, and these flaps are cosmetically inferior to muscle flaps.

Free flaps (free tissue transfer) are those in which the native blood supply is completely severed, with transplantation of the flap to a separate body area. They can be muscle, myocutaneous, fasciocutaneous, or axial flaps. They can be used to provide function (free neurotized muscle transfer for correction of facial nerve palsy). Revascularization is accomplished by microvascular anastomosis.

P.485

FIGURE 26-5 A: Arterial blood supply in musculocutaneous flaps. B: The five patterns of vascular anatomy of muscle. (Adapted from

Mathes SJ, Nahai F. Classification of the vascular anatomy of the muscles: experimental and clinical correlation. Plast Reconstr Surg. 1981;67:177.

)

P.487

Uses of flaps include:

Wound closure in areas of poor vascularity (e.g., wounds overlying bare bone, cartilage, nerves, or tendons; radiation -injured tissue)

Facial reconstruction (e.g., the nose or lips)