Atlas of General Surgical Techniques (Courtney M. Townsend Jr., B. Mark Evers)

C H A P T E R 102 • Donor Nephrectomy 1139

External oblique muscle

Rectus

muscle Internal oblique muscle

Gerota’s

fascia

Peritoneum

12th rib

Latissimus

muscle

FIGURE 102–13

Ureter

FIGURE 102–14

C H A P T E R 102 • Donor Nephrectomy 1141

OPEN RIGHT DONOR NEPHRECTOMY

For open right nephrectomy, the patient is set up as for a left nephrectomy, with the right side up. The main differences with the right nephrectomy are that the kidney is somewhat lower, the renal vein is thinner and shorter, and the gonadal vein drains into the IVC.

RETROPERITONEAL LAPAROSCOPIC APPROACH TO THE KIDNEY

Some centers advocate a retroperitoneal approach to right and left nephrectomy; the main advantages appear to be avoidance of the peritoneal cavity, decreased risk of ileus, and lesser hemodynamic effects with unilateral pneumoperitoneum.

The disadvantages of a laparoscopic retroperitoneal approach are a smaller working space, a steeper learning curve, and some reports of more prolonged warm ischemia times.

USE OF THE ROBOT

The robot can be used for either pure laparoscopic or hand-assisted nephrectomy. The advantages include retention of binocular vision and greater flexibility of the operating head.

The chief disadvantage is expense.

STEP 4: POSTOPERATIVE CARE

A Foley catheter is left in the donor overnight.

The patient is monitored for bleeding.

Early ambulation (on day of surgery) is encouraged.

The patient should not take food or fluids the first day and should start clear liquids the next day.

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STEP 5: PEARLS AND PITFALLS

Success of the live donor kidney transplant begins with optimal hemodynamic management of the donor. Adequate hydration of the donor preoperatively and intraoperatively cannot be overemphasized.

Ensure diuresis before clamping of the vessels to counter the effects of renal artery traction and the effect of the pneumoperitoneum on renal blood flow.

Coordinate between the donor and recipient operating rooms to minimize cold ischemia time.

SELECTED REFERENCES

1. Potter SR, Buell JF, Hanaway M, Woodle ES: Laparoscopic live donor nephrectomy: Rationale, techniques and implications. Semin Dial 2001;14:365-372.

2. Ratner LE, Fabrizio M, Chavin K, et al: Technical considerations in the delivery of the kidney during laparoscopic live-donor nephrectomy. J Am Coll Surg 1999;189:427-430.

3. Bolte SL, Chin LT, Moon TD, et al: Maintaining urine production and early allograft function during laparoscopic donor nephrectomy. Urology 2006;68:747-750.

CH A P T E R 103

SKIN GRAFT—SPLIT THICKNESS

AND FULL THICKNESS

James J. Gallagher and David N. Herndon

STEP 1: SURGICAL ANATOMY

Figure 103-1 shows a detailed cross-section of the skin.

First degree burn

Superficial

Epidermis

Second degree burn

Deep

Dermis

Third degree burn

Subcutaneous fat

Fascia

Fourth degree burn

Muscle

FIGURE 103–1

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INDICATIONS

The most common reason for skin grafting is a deep secondor third-degree burn (see Figure 103-1).

Other causes include infection, cancer, reconstruction, and trauma.

Burn injury that is clearly third degree should be surgically excised and grafted promptly unless it is small enough to allow healing by secondary intention.

Second-degree burns are either superficial or deep partial thickness. This distinction can be difficult to determine clinically.

As a general rule, burns that will heal within 2 to 3 weeks with good wound care should be allowed to do so without grafting. During this period, the clinician has a number of choices to manage the second-degree wound: removal of blisters and tangential excision of dead tissue followed by the application of homograft, xenograft, Biobrane, or other artificial skin. Alternatively, these burns may be treated with serial dressing changes with a topical antimicrobial, typically silver sulfadiazine. Clinical judgment is the best guide as to burns that will heal and those that will not.

The following is a review of debridement and grafting strategies for burns, as well as modern techniques of skin grafting for all skin defects.

Free skin grafts will take to (in order of declining take rate) healthy dermis, fascia, fat, muscle, periosteum, and peritenon. Granulation tissue growth indicates a healthy bed for grafting; the granulation tissue maybe removed before the graft is placed, or it may be left in place depending on physician judgment. Removal improves topographic irregularities, as well as the biofilm of bacterial colonization that may decrease graft take. Removal is associated with increased operative blood loss.

Modern dermatomes come in a variety of types. Most are powered by compressed air or electricity (Figure 103-2).

Calibration for depth of harvest is in the thousandths of an inch. Typically, a graft is taken between 8 and 15 thousandths of an inch; the choice of depth varies with the area to be grafted and the overall needs of the patient. We have found that the calibrations can be inaccurate, and we routinely use the sharp edge of a scalpel to act as a mechanical check of cutting depth. Reharvesting of donor sites is limited by the healing rates of the donor sites, with thinner harvest sites obviously healing quicker. Each time the donor is harvested, the epithelium is taken with some amount of dermis. The epithelium regrows, but the underlying dermis does not. Deeper donor sites have the potential to produce more scarring. Defects to the head and neck area are best covered with skin from above the clavicles. The shaved head provides a reliable donor site with excellent healing potential; a caution is in order to avoid areas of alopecia (senescent or autoimmune). Donor site placement should

C H A P T E R 103 • Skin Graft—Split Thickness and Full Thickness 1145

be mindful of normally exposed areas in conventional dress patterns. Full-thickness grafts require either the donor site to be closed or that a split-thickness graft be placed for healing. Depth greater than 15 to 20 thousandths of an inch with the dermatome may near full thickness and require the donor site to be autografted. It is common to harvest small amounts of skin to cover areas of the palm or the eyelids. These small full-thickness donor sites are usually closed primarily.

Dermatome

FIGURE 103–2

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STEP 2: PREOPERATIVE CONSIDERATIONS

Burn and skin defect closure operations are elective or semielective operations.

Preoperative antibiotics are chosen to cover gram-positive organisms in smaller burns. Patients with larger burns, residents of the intensive care unit, or patients with other history of contamination should have broader antibiotic coverage to include gram-negative organisms, as well as institutional-specific coverage of resistant organisms.

Most of the preoperative dressings used provide some topical antimicrobial. Blood loss of 0.5 to 1.0 mL/cm2 area (depending on the timing of surgery) that is prepared can guide the surgeon as to the need for perioperative blood transfusion.

ANESTHESIA

Burn and wound surgery is performed with the patient under a combination of local anesthesia, conscious sedation, and general anesthesia depending on the extent of the area involved.

Efforts at minimizing blood loss during surgery may involve tourniquets in extremity burns; topical epinephrine; topical thrombin; and possibly, tumescence of the tissue with balanced salt solution, with or without epinephrine.

The need for large access will best be judged by the area to be treated. Clear communication with the anesthesia care team is critical, because blood loss is mainly into the laparotomy pads and can easily be underestimated.

Volume replacement during surgery in patients with burns over more than 40% of the body is largely with blood and fresh frozen plasma. Maintenance of temperature is critical; this can be accomplished by warming the operating room and fluids and using blankets and radiant heaters.

POSITION

The patient’s position on the operating table is determined by the area to be treated and the choice of donor site. We routinely use a specially designed operating room for larger burns, which allows for an on-table bath and hanging of an extremity to facilitate circumferential work.

C H A P T E R 103 • Skin Graft—Split Thickness and Full Thickness 1147

STEP 3: OPERATIVE STEPS

Begin by preparing the wound bed. This will allow a clear estimation of the size of the defect and will allow for hemostasis to occur while the surgeon’s attention is directed at the harvesting of autograft.

For adequate wound bed preparation, the surgeon must remove the eschar down to healthy tissue to ensure a bed that will accept the skin. There are many choices to accomplish this goal. Most commonly, tangential excision is chosen. Tangential excision is achieved by serially cutting through the eschar until viable dermis or other viable tissue is reached. Specialized knives have been invented for this purpose (Figure 103-3).

Goulian knife

Watson knife

FIGURE 103–3