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

1 0 2 0 S E C T I O N X I I • VA S C U L A R

STEP 2: PREOPERATIVE CONSIDERATIONS

The patient should be placed supine with the head rotated to the contralateral side from the planned incision. Left or right sides may be used, but care must be taken not to injure the thoracic duct on the left. A roll or bump under the flank may facilitate exposure of the lateral upper abdomen (Figure 92-2, A).

If one of the jugular veins has been dissected or catheterized previously, using the other untouched vein may be prudent.

STEP 3: OPERATIVE STEPS

1.INCISION

The patient is placed supine with the head rotated to the side opposite the vein being used. The patient is placed in a Trendelenburg position to engorge the vein by increasing the venous pressures. A roll or bump under the flank may facilitate exposure of the lateral upper abdomen. The venous incision is made approximately 1 fingerbreadth above the clavicle and between the two heads of the sternocleidomastoid muscle. The abdominal incision is made lateral to the rectus muscle, approximately 2 fingerbreadths below the costal margin and transversely for approximately 3 to 5 cm (Figure 92-2, B).

1 0 2 2 S E C T I O N X I I • VA S C U L A R

2. DISSECTION

The skin, subcutaneous fat, and platysma muscle are incised. The sternal and clavicular heads of the sternocleidomastoid muscle are split. The jugular vein is located lateral to the carotid artery and can be used as a landmark to facilitate the identification of the vein. The sheath that enwraps the vein keeps the vein from collapsing. This facilitates the circumferential dissection of the vein. If the dissection is close to the vein, damage to adjacent structures is minimal. The vein may have small tributaries coming into it, and disruption of these may cause a moderate amount of bleeding. Identification and ligation with division of these small vessels is advised. Elastic vessel loops are used proximally and distally to allow occlusion of the blood flow and control of the vessel in the operative field (see Figure 92-2, B).

After the skin incision is made, the subcutaneous fat is incised to the muscle. A 0.5% to 1% solution of lidocaine is injected into the subcutaneous tract from the abdominal incision to the jugular incision. The tract should run laterally on the chest wall, outside the area of the breast and over the clavicle. Marking the route of the tract on the skin will help you stay on course when passing the catheter/shunt. Push a vascular tunneling device through the subcutaneous tissues deep to the skin but above the muscle fascia, following the tract that was injected with the anesthetic. Pull the shunt from the bottom up, taking care to orient the shunt correctly. Denver shunts have a one-way pump that should fit over the ribs. The LeVeen shunts have a multiperforated abdominal end and a venous end that can be cut to appropriate length (Figure 92-3).

C H A P T E R 92 • Insertion of Peritoneal Venous Shunts 1023

Shunt tubing in subcutaneous tunnel

FIGURE 92–3

1 0 2 4 S E C T I O N X I I • VA S C U L A R

The muscle in the abdomen should be split to expose the peritoneum. A purse-string with a radius of 1 cm should be made in the peritoneum. Permanent suture is advised. Incision of the peritoneum within the purse-string is made with electrocautery or scissors. While the ascites is draining, place the intra-abdominal end of the shunt into the opening and thread the tubing into the peritoneal cavity. Secure the purse-string around the shunt. If using the LeVeen shunt, thread the entire catheter in until the disc is flush with the peritoneum. Connect the tubing running toward the neck incision to the port on the side of the abdominal disc. Secure the tube to the disc with a large tie. If using the Denver shunt, thread the catheter in until the “valve/pump” can be positioned over ribs 9 to 11. The subcutaneous tissue will have to be dissected to create a cavity to support the pump. The pump should be secured to the underlying tissue to avoid migration (Figure 92-4, A).

Prime the tubing by aspirating at the venous end until there are no bubbles in the tubing. If using the Denver shunt, press the pump several times until the fluid comes out the end of the shunt. Clamp the tubing at the site where it enters the neck incision from below. Estimate the length of the venous end of the shunt by placing the tubing onto the sternum. Cut the tube at the point where it crosses the manubrium. Do not cut the tube at an angle, because the tube may push against the side wall of the vein and obstruct the fluid flow

(Figure 92-4, B).

1 0 2 6 S E C T I O N X I I • VA S C U L A R

Place a purse-string suture in the anterior wall of the jugular vein with Prolene suture

(3-0 or 4-0). Occlude the vein with the elastic loops. Incise the vein within the purse-string. Raise the head of the patient to approximately 35 degrees. Keep the tubing clamped at skin level and tubing distal to the clamp filled with the ascitic fluid or heparinized saline (2500 U heparin in 250 mL normal saline).

Hold the edge of the incised vein and insert the tubing. Take tension off the lower elastic loop to allow the tube to be advanced into the thorax. Secure the purse-string around the tubing (Figure 92-5).

FIGURE 92–5

1 0 2 8 S E C T I O N X I I • VA S C U L A R

STEP 4: POSTOPERATIVE CARE

The patient should be admitted for an overnight stay. The potential problems are fever, fluid overload, and disseminated intravascular coagulation (DIC). Fever is usually transient and treated symptomatically. The identification of infection occurs in approximately 5% of those patients with fever and warrants treatment. Pulmonary edema occurs in approximately 10% of the patients but usually can be handled with diuretics. DIC is usually subclinical and can be treated expectantly. The worst case scenario is fulminant bleeding, which requires removal of the shunt. The bleeding may be related to exposure of the systemic circulation to fibrin split products (FSP)–rich ascitic fluid that may activate the coagulation mechanism. Bleeding complications do not appear to be related to the severity of the post-shunt coagulopathy but rather to the severity of liver dysfunction and presence of preoperative DIC, probably caused by the liver disease.

STEP 5: PEARLS AND PITFALLS

The contraindications for shunt insertion should include pseudomyxoma peritonei, recent or current infection, preoperative coagulopathy, liver failure, and loculated ascites. Relative contraindications include positive cytologic findings in ascitic fluid and concurrent cardiac failure. Bloody ascites and ascitic fluid protein content greater than 4.5 g/L are also considered contraindications to shunting, secondary to increased risk of shunt blockage from clot or fibrin plugs.

If a patient has had episodes of variceal bleeding, the risk of rebleeding postshunt is great secondary to the risk of postshunt coagulopathy and increased intravascular volume.

SELECTED REFERENCES

1. Smith EM, Jayson GC: The current and future management of malignant ascites. Clin Oncol (R Coll Radiol) 2003;15:59-72.

2. Becker G, Galandi D, Blum HE: Malignant ascites: Systematic review and guideline for treatment. Eur J Cancer 2006;42:589-597.

3. Suzuki H, Stanley AJ: Current management and novel therapeutic strategies for refractory ascites and hepatorenal syndrome. QJM 2001;94:293-300.