• Non ci sono risultati.

32. Wound Management and Complications

N/A
N/A
Protected

Academic year: 2022

Condividi "32. Wound Management and Complications"

Copied!
11
0
0

Testo completo

(1)

32. Wound Management and Complications

Stanley C. Hewlett, M.D.

Gary C. Vitale, M.D.

There are many advantages of minimal access surgery (MAS) over tradi- tional surgery. In addition to the physiologic benefits associated with avoidance of lengthy incisions, smaller incisions are cosmetically superior. The decreased traumatic insult to the body wall results in less postoperative pain and discom- fort as well as decreased narcotic requirement. This minimized traumatic insult is directly related to the shortest, quickest recovery possible followed by an earlier return to the patient’s preoperative lifestyle.

Although the incidence of some wound problems may be diminished by avoiding a lengthy incision, MAS wounds are still at risk for traditional wound complications. The MAS surgeon should strive to recognize and treat these com- plications as early as possible. Further, it should be the goal of the surgeon to minimize the incidence of these complications via meticulous attention to wound management and closure during the operation.

A. Infectious Wound Complications

It has been suggested that one of the advantages of MAS is a decreased rate of wound infection, although there have been no randomized controlled trials that specifically considered this issue. One mechanism by which MAS methods may be associated with fewer infections is better preserved postoperative cell- mediated immune function. It must be remembered that the choice of surgical access method is only one of a number of variables that influence the develop- ment of wound infection. To minimize wound infection rates, the MAS surgeon should be well informed of the various factors that may increase the chances of an infection developing.

1. Risk factors a. Patient-related

i. Age

ii. Chronic illness iii. Diabetes iv. Malnutrition

v. Hypoxemia vi. Shock

vii. Untreated active infections (pulmonary/urosepsis)

(2)

viii. Hypochlorhydria

ix. Wound classification (Table 32.1) b. Iatrogenic

i. Steroids or other immunosuppressive medications ii. Inadequate sterile technique

iii. Excessive operative times

iv. Surgical technical errors. Less than optimal surgical tech- nique may result in hematomas, seromas, and unnecessary tissue trauma, which decrease the size of the bacterial inocu- lum required to cause a wound infection. Inappropriate cautery use, excessive force in tissue handling, disregard for hemostasis, and unnecessary residual foreign bodies are to be avoided.

2. Prevention

a. Optimize patient and iatrogenic risk factors, where feasible (see above).

b. Appropriate use of systemic perioperative antibiotics (see Chapter 5). A larger bacterial inoculum is necessary for an infec- tion to develop when perioperative antibiotics are used. Routine antibiotic prophylaxis is advised when performing procedures associated with increased rates of simple wound infections, as well as for operations associated with lower rates of infections where the development of an infection can have devastating results (vascular prosthetics).

i. It is important to achieve therapeutic serum levels before making the incision by administering the intravenous antibi- otics well before the start of the operation.

ii. Use an antibiotic that will adequately cover the organisms typically found in wound infections that develop after the procedure in question.

iii. Re-dose as needed during surgery depending on the half-life of the antibiotic.

c. Operative site preparation. Consider a preoperative shower treat- ment. Decreasing excess organic debris (exfoliated skin cells, oils, dirt, etc.) at the skin surface that falls within the operative field facilitates the antiseptic action of iodophor skin prep. The reduction of skin flora bacterial counts at the planned incision site reduces the extent of bacterial contamination of the wound.

Table 32.1. Risk of infection in surgical wounds.

Surgical wound

classification Risk of Infection (%)

Clean 1–2

Clean-contaminated 2–4

Contaminated 7–10

Infected 10–40

(3)

i. Avoid unnecessary trauma from hair removal techniques. If hair removal is necessary, use electrical clippers immedi- ately before entering the operating room (OR). Shaving is associated with a 5- to 10-fold increase in wound infection rates, especially if done before the day of surgery. The minute trauma from a razor leads to microexudative wounds with higher bacterial counts as well as an increase in skin surface organic debris. Wet shaving (with soapy water) decreases the amount of trauma and also controls dispersion of loose hair. Loose hair in the operative field can potentially carry resident skin flora into the depths of surgical incisions.

ii. Avoid abrading or massaging the skin after it has been prepped (i.e., wiping off antiseptic) because this decreases the antiseptic activity and, simultaneously, delivers an increased number of bacteria to the skin surface from deep within skin appendages. However, removal of pooled iodophors is recommended to prevent skin irritation.

iii. Strict adherence to the standard principles of sterility. There is always a chance the patient may require conversion to an open approach. Thus, the patient should be prepped widely;

this will greatly decrease the probability that the incision required for conversion will extend beyond the prepped area.

iv. Utilize meticulous surgical technique. Poor surgical tech- nique may result in hematomas, foreign bodies, deadspace, and retained necrotic tissue, which impair host immune responses and increase the chances of infection by decreas- ing the size of bacterial inoculum required to generate a wound infection.

(a) Preoperative local anesthetics that contain epinephrine can increase the wound infection rate due to impair- ment of local blood flow. Consider avoiding them in patients with multiple risk factors for wound infection.

(b) Make adequate-sized skin incisions. The integrity of the pneumoperitoneum should not be maintained at the skin level via an overly snug port incision that may result in ischemia and marginal wound necrosis. An overt wound infection is more likely to develop in this setting; alternately, a subclinical infection may arise that is related to the pronounced scar that may develop in these wounds.

(c) Dressings. Occlusive dressings are used to increase or maintain wound humidity in order to encourage reep- ithelialization. This humid setting is also conducive to bacterial overgrowth. After the first 24–48 hours, the wound, which should be reepithelialized by that point, should be left open to the air.

d. Consider visceral preparation. A bowel preparation may reduce perioperative infectious complications in colon surgery. Bowel preparation components include:

(4)

i. Mechanical bowel preparation ii. Antibiotic bowel preparation

3. Early postoperative wound infections. These extremely rare infections are associated with particularly high morbidity and mortality rates due to two factors: first, these infections are often aggressive and poten- tially lethal, and, second, they often go unrecognized until their later stages.

a. Presentation.

i. First 24–48 hours after surgery ii. Wound signs (may be subtle or absent)

(a) Erythema (b) Edema (c) Tenderness

(d) Dishwater discharge (Streptococcus) (e) Crepitance (Clostridia)

iii. General signs (usually subtle, if present) (a) Anxiety, feeling of impending doom (b) Tachycardia

(c) Tachypnea (d) Fever

iv. Progression beyond these early stages quickly leads to over- whelming sepsis, shock, and death.

b. Management i. Diagnose early.

(a) Maintain a high index of suspicion.

(b) Carefully examine all wounds, especially those of patients who manifest a fever in the early postoperative period.

(c) Gram stain suspicious discharges.

ii. Immediate surgical treatment: incision and debridement (I&D) emergently at the bedside or in the OR if necessary.

iii. Use appropriate intravenous antibiotics.

4. Regular postoperative wound infection/abscess a. Presentation

i. 5–10 days postoperative ii. Wound signs

(a) Erythema (b) Tumescence (c) Tenderness (d) Warmth

(e) Purulent discharge iii. General signs

(a) Fever (b) Fatigue (c) Hyperglycemia

iv. Left untreated, these can be life-threatening, particularly in patients with multiple risk factors and compromised host defenses.

b. Management

(5)

i. Fully open the wound (at the skin and subcutaneous level).

ii. Drain abscess adequately (break up loculations and all puru- lent pockets).

iii. Assiduous wound care (debridement, where necessary, and frequent dressing changes).

iv. Antibiotics in patients with the following risk factors:

(a) Diabetes

(b) Immunosuppression

(c) Prosthetic heart valves or murmurs requiring prophy- laxis

(d) Those with multiple risk factors v. Antibiotics in wounds that manifest:

(a) Necrotic fascia

(b) Necrotic subcutaneous tissue

B. Port Site Bleeding Complications

Bleeding complications of surgical wounds either occur during or after surgery (see Chapter 21).

All patients are at some risk for bleeding complications; however, those with hemostatic disorders are at increased risk. Such conditions may be the result of a disease process (e.g., cirrhosis-induced liver dysfunction), an inherited disor- der (hemophilia, factor deficiencies, or von Willebrand’s disease) or related to a medication [aspirin, selected nonsteroidal antiinflammatory drugs (NSAIDs), coumadin, or heparin]. The surgeon should strive to limit and, hopefully, prevent perioperative bleeding. Preoperative identification of the high-risk patient pop- ulation is a critical step in this process.

1. Prevention

a. Identification of patients at risk for perioperative bleeding.

i. History and physical examination. Pertinent questions in regard to bleeding and coagulation:

(a) Easy bruisability

(b) Voluminous bleeding with incidental trauma or during menses

(c) Bleeding gums on tooth brushing

(d) Personal or family history of bleeding disorders (e) History of unusual hemarthroses

(f ) Jaundice

(g) Liver/spleen disorders

(h) Medication history: use of anticoagulants, NSAIDs, or other medications that may interfere with hemostasis ii. Patients with a suggestive history or physical examination

findings should undergo a laboratory analysis.

(a) Standard quantitative evaluation (i) Prothrombin time (PT/INR) (ii) Partial thromboplastin time (APTT) (iii) Platelet count

(6)

(b) Specialized evaluations

(i) Bleeding time: assesses platelet function (ii) Factor assays: quantitative functional assay of the

various clotting factors

(iii) Thromboelastography: analyzes the dynamics of functional clotting

b. Optimize patients documented to have abnormal hemostasis.

i. Self-correction of a medication-induced therapeutic coagulopathy.

(a) Coumadin (warfarin): stop warfarin 4–5 days before surgery. Depending on the indication for anticoagula- tion and the recommendations of the patient’s physi- cians, in-hospital intravenous heparin for 2–3 days immediately before the operation (after the coumadin has been stopped) may be advised (a so-called heparin window). The heparin anticoagulates the patient but is rapidly reversible (within 3–4 hours time) once stopped before the operation. Furthermore, warfarin should be withheld from patients in the early postoperative period, or the dose reduced initially if general anes- thetics that affect liver drug metabolism were adminis- tered to the patient (e.g., Propofol). An exaggerated warfarin effect due to increased drug half-life sec- ondary to decreased hepatic metabolism can be antici- pated in this setting.

(b) Aspirin (ASA): aspirin has an irreversible effect on platelets. The induced platelet dysfunction is “cor- rected” only when new platelets are released. For this reason, ASA-containing medications should be stopped 10 days before surgery.

(c) Ibuprofen: this drug’s antiplatelet effect is reversible.

Although most authorities advise stopping ibuprofen 5 days before surgery, a 6- to 12-hour period off this med- ication should be adequate.

ii. Active reversal of a medication-induced therapeutic coagu- lopathy: in situations where it is not possible to delay surgery while the medication-induced coagulopathy autocorrects, it is usually necessary to give vitamin K or to replace the clot- ting factors via transfusion of fresh frozen plasma or other blood products. Although minimizing the coagulopathy is almost always appropriate, it should be recognized that there is a risk of possibly overshooting the baseline and rendering a patient hypercoagulable. Thrombotic complications are sometimes a greater concern than the risk of bleeding com- plications. A recommendation from a hematologist or other specialist managing the patient’s antithrombotic treatment in regard to reversing the coagulopathy can be helpful.

However, when faced with active or uncontrolled bleeding, reversal is always necessary.

(7)

(a) Warfarin

(i) Parenteral vitamin K.

Effects are unpredictable, require a functional liver, and need several hours to days for complete correction of coagulopathy.

(ii) Fresh frozen plasma (FFP) transfusion (factors II, VII, IX, X).

FFP effects are temporary (due to the 4-hour half- life of factor VII), and therefore repeated adminis- tration of FFP or other blood products is required.

iii. Correction of a naturally occurring coagulopathy, possibly of unknown etiology.

(a) Consult a hematologist if needed.

(b) Use FFP, vitamin K, and/or other blood products.

(c) A minimum of 30% clotting factor activity is necessary for adequate perioperative hemostasis.

c. Meticulous operative technique: abdominal wall vascular injuries may occur during port insertion. Most commercially available ports utilize a sharp trocar of some type to penetrate the abdom- inal wall. Trocar designs vary considerably; the surgeon should be familiar with the mechanics of a given trocar before using it in humans. There are certain basic guidelines that should be fol- lowed when inserting a port, regardless of the specific type of port/trocar system that is being used.

i. Abdominal wall penetration should never be tangential. The trocar and port should enter the abdomen at a 90° degree angle to the skin surface. Angled or tangential insertion toward the intended operative field has been erroneously rec- ommended to facilitate the insertion of instruments into the proper quadrant. However, angled insertion increases the volume of tissue that the trocar must traverse and thereby increases the chances of vascular injury. Further, when an injury does occur, the bleeding is more difficult to control when the path of the port is angled.

ii. Complete the dermal incision before utilizing the trocar to penetrate the fascia. Although using the trocar to divide the dermis does not increase the chances of a major abdominal wall vascular injury, it does increase the chances of incur- ring a visceral injury because of the increased force required to traverse the dermis. Trocar penetration of the dermis may also result in subcutaneous bleeding from a dermal or sub- dermal vessel (usually a vein).

iii. The used of preincisional local anesthetics with epinephrine may delay the onset of bleeding. The port, when in place, may also prevent bleeding via direct pressure against the wound’s circumference. At the end of the case, the ports should be removed under videoscopic guidance. After removal, the port wound should be briefly observed from the inside and outside for bleeding.

(8)

d. Avoid injury to named vessels of the body wall.

i. Epigastric artery

(a) Any trocar placed within the rectus sheath in the para- median anterior abdominal wall risks injury to this vessel. Ports should be placed either in the midline or lateral to the edge of the rectus sheath to eliminate the possibility of epigastric injury. When it is necessary to insert a port through the rectus muscle, an open cut- down technique is best employed.

(b) Caution should be used in cases where a patient may have had an interruption in collateral epigastric flow [previous Kocher incision, or coronary artery bypass graft (CABG) with internal mammory artery (IMA) graft]. In these cases, an injury to an uncollateralized epigastric can result in abdominal wall ischemia with poor wound healing and even complete necrosis of the affected portions of the abdominal wall between the injury and the site of disruption of the collateral epi- gastric artery.

ii. Intercostal arteries

(a) Thoracic ports should be placed over ribs to avoid injury to these vessels, which run below each rib.

(b) Blunt-tipped ports should be used instead of sharp cutting ports.

2. Management of bleeding

a. Intraoperative abdominal wall bleeding. Significant bleeding that occurs as a result of trocar insertion can be controlled via defin- itive or temporizing measures when recognized. If the latter course is chosen, it must be remembered that definitive control must be obtained at the end of the case.

i. Immediate external direct approach

Remove port, enlarge port incision, and identify and ligate the injured vessels.

ii. Temporary MAS techniques (a) Port manipulation

(i) Torquing of port so as to tamponade the bleeding vessel (most often not successful for transected epigastric vessels)

(ii) Use of conically shaped port anchoring device to tamponade the bleeding

1. Similar to Hasson trocar shape 2. Often threaded

(b) Foley occlusion (via inflated balloon) of wound (c) Transabdominal wall horizontal mattress sutures (port

left in place)

(i) Two sutures placed: one cephalad and the other caudad to the port site so as to encircle the epi- gastric vessels in two places (thus blocking inflow and outflow to the injured vessels).

(9)

(ii) Number 2 nylon or similar heavy monofilament suture with largest curved needle (2.5–3 inches long, usually used for placement of retention sutures).

(iii) Needle straightened.

(iv) Needle passed from outside to inside via laparo- scopic visualization just lateral to the vessel location.

(v) Needle grasped via laparoscopic instrument, pulled into the abdomen, carefully turned around, and then passed back outside at a more medial point to encircle the vessel.

(vi) Two external ends are tied snugly over a gauze but- tress to occlude the injured vessel.

(d) Endo-Kitner pressure (intercostal vessels)

iii. Definitive MAS techniques (employed at the time injury is recognized)

(a) Endoclose (USSC) hemostatic stitch (b) Bipolar cauterization of smaller vessels (c) Endoclip

iv. Delayed definitive control at the end of the case (via exter- nal means, 2.a.i. above)

b. Postoperative bleeding and hematoma

i. Hemodynamically significant postoperative bleeding requires rapid and definitive surgical control no matter the source (intraabdominal or abdominal wall). Such control should be obtained in the OR setting.

(a) Substantial abdominal wall bleeding may dissect in the abdominal wall to the flank, back, or groin if the peritoneal and skin incisions have been well closed. In this case, large ecchymoses and purple-colored dis- coloration of the abdominal wall, flank, or back may be noted.

(b) Abdominal wall bleeding may also collect in the abdomen. In this case, physical examination may reveal mild to moderate distension and, at worst, minimal ten- derness because blood is often not irritating and is rel- atively innocuous to the peritoneum.

(c) At the time of reoperation, clotted and extravascular blood should be evacuated from the patient (consider using a cell-saver device where reasonable).

(d) Postthoracoscopy port site bleeding usually presents as a hemothorax.

ii. Significant abdominal wall bleeding should be controlled via ligation, cauterization, or other direct means through the open wound (often enlarged). Temporarily, external direct pressure can be used to control the bleeding. Bleeding from the abdominal wall may track between the fascial sutures to the subcutaneous planes and then to the outside via the skin

(10)

incision, in which case the dressing will be stained or saturated.

iii. Oozing from multiple surgical sites (and possibly I.V. sites) should raise the suspicion of an undiagnosed bleeding disorder.

(a) Apply pressure in 5-minute intervals.

(b) Warm the patient.

(c) Initiate a laboratory evaluation and correct the coagu- lopathy once it has been documented.

C. Port Site Seroma

This unusual complication of port wounds can be difficult to distinguish from a wound infection, hematoma, or even an early postoperative hernia. The typical presentation is a painless ballotable swelling at a healing port site (usually 1–5 days postoperatively). If a hernia is suspected, transcutaneous ultrasonogra- phy via an appropriate transducer (8–10 MHz) should reveal if the fascial closure is intact. Signs of inflammation should be absent in an uncomplicated seroma;

if present, a wound infection should be ruled out with aspiration and gram stain, or even an I&D of the wound. Obviously, this should be done only if a hernia is not present. Seromas usually resolve spontaneously within days unless com- plicated by a superinfection. On occasion, however, they may persist for weeks or longer. Repeated aspiration of simple seromas followed by pressure dressings may enhance resolution but introduces the possibility of bacterial seeding. Close observation, provided the patient has been well educated as to what are the wor- risome signs and symptoms, seems to be just as effective.

A feared complication related to the presence of ascites has been uncon- trolled leakage of ascitic fluid from the wound. This rare complication can be avoided by closing all fascial port sites, combined with aggressive medical man- agement of ascites perioperatively. However, infectious and bleeding complica- tions occur more frequently in patients with ascites.

D. Poor Cosmesis

Some patients clearly are interested in the cosmetic benefits that MAS approaches offer in regard to avoiding a lengthy incision. However, the cosmetic results can be further improved if the location and orientation of the port inci- sions are carefully considered and care is taken when closing the wounds.

1. Incision placement

a. Orientation of the axis of incision should be in the direction of Langer’s lines of tension. This will minimize the intrinsic poten- tial of the wound to gape. This also facilitates adequate skin edge apposition during wound closure and decreases the tension needed to close the wound, no matter which method is used (Steri-strip, adhesives, staples, or suture).

(11)

b. Placement of the incisions in prominent skin creases makes them less apparent. Using the recessed superior aspect of the umbili- cus, or even the base, rather than the inferior skin trough will obscure this incision from normal view. This is a bikini-friendly umbilical incision.

2. Incision size. In regard to port wound size, smaller is not necessarily better. The incision should be large enough to accept the selected trocar size (3, 5, 10, or 15 mm, etc.) easily, without any marginal incisional pressure. There should not be a pneumoperitoneal seal at the level of the skin. Excessive pressure of the trocar against the skin will result in compromised wound circulation and possible marginal necrosis of the skin wound. This is manifested as a postoperative incision that appears excessively reddened and hypertrophic.

3. Incision closure.

a. Closure of a well-developed or pronounced Scarpa’s fascia will reduce the incidence of a divit scar. The sutures used for closing these deeper layers should not entangle the subcutaneous tissue.

b. Several options are available for skin closure. Simple tape, wound adhesives, staples, and sutures each have unique advantages.

Familiarity with more than one technique is recommended. Of course, the use of meticulous surgical technique when closing the wound yields the best results. The care of the abdominal wound should not be left to chance. The surgeon’s recommendation for the wound dressings should be clearly communicated to the ancil- lary staff as well as the patient.

E. Neuralgia

This disappointing complication can be very difficult to manage for the surgeon. Before referral to a pain center, the surgeon should evaluate the patient to ensure that there is no other local wound process to account for the patient’s symptoms such as infection, hernia, or tumor recurrence. Initial treatment includes reassurance and oral nonnarcotic analgesics. Trigger point injections can help define the potential benefit of neuroma excision or permanent neurol- ysis injections. In regard to thoracoscopy, neuromas can be prevented by avoid- ance of the subcostal neurovascular bundle during trocar insertion.

F. Selected References

Balli JE, Franklin ME, Almeida JA, Glass JL, Diaz JA, Reymond M. How to prevent port- site metastases in laparoscopic colorectal surgery. Surg Endosc 2000;14(11):

1034–1036.

Fry DE. Surgical Infections. Philadelphia: Lippincott-Raven, 1995.

Riferimenti

Documenti correlati

While the image captioning model is conditioned on the input image and is in charge of mod- eling a sequence of output words, the region selector is in charge of choosing the

Interestingly, the trajectory associated to the highest well-being (blue-solid) corresponds to the lowest average value of the labour supply and highest average value of

To evaluate the economic sustainability of the woodchip production from kiwi clear-cut, the costs were determined by considering different amounts of biomass available per unit

I discuss in Section 3.2 the approach (i.e., what is a transition system, how I chose to define it and what is a model), in Sections 3.3, 3.4 and 3.5 I present a discussion on (i) how

If occupied states from the LAO surface contribute to tunneling, we should expect an asymmetric I-V characteristics, with a much higher tunneling current for negative bias volt-

Il mantenimento delle caratteristiche di stile o di lingua che connotano il testo di partenza (connotazione) rappresenta un’altra scelta che consiste

In order to do so, we provide a three-step presentation: (1) a critical overview of the meanings and uses of ambivalence in the recent sociological literature, (2) an inquiry into

Because keratinocytes can also serve as a source of growth factors and specific matrix molecules, cultured epithelial allografts (CEAllo) have been evaluated for their ability