Posterior Tibial Thrombectomy

From Reference 29. Used with permission.

From Reference 29. Used with permission.

TABLE 45.3 Technique of Contemporary Venous Thrombectomy

1. Identify etiology of extensive venous thromboembolic process a. Complete thrombophilia evaluation b. Rapid CT scan of chest, abdomen, and pelvis

2. Define full extent of thrombus a. Venous duplex examination b. Contralateral iliocavagram, MRV, or spiral CT

3. Prevent pulmonary embolism (numerous techniques)

a. Anticoagulation b. Vena caval filter (if nonocclusive caval clot)

c. Balloon occlusion of vena cava during thrombectomy d. Positive end-expiratory pressure during thrombectomy

4. Perform complete thrombectomy a. Iliofemoral (vena cava) thrombectomy b. Infrainguinal venous thrombectomy (if required)

5. Ensure unobstructed venous inflow to and outflow from thrombectomized iliofemoral venous system a. Infrainguinal venous thrombectomy (if required)

b. Correct iliac vein stenosis (if present)

6. Prevent recurrent thrombosis a. Arteriovenous fistula b. Continuous therapeutic anticoagulation c. Catheter-directed postoperative anticoagulation (if infrainguinal venous thrombectomy is required)

d. Extended oral anticoagulation

MRV, magnetic resonance venography; CT, computerized tomography.

whether thrombus has extended into the vena cava. Magnetic resonance venography with gadolinium or spiral computerized tomography (CT) scan with contrast may obviate the invasive procedure in some patients. Our preference is spiral CT scan with contrast, since a rapid CT scan of the chest can be performed simultaneously to evaluate for PE and other pathology, followed by a CT scan of the abdomen and pelvis, which not only localizes the proximal extent of thrombus, but also examines for intraabdominal and pelvic pathology.

During the operation, complete thrombus removal is ensured by completion phlebography. Correction of an underlying venous stenosis with balloon angioplasty and stenting (if needed) is critical to obtain unobstructed venous drainage into the vena cava. Residual iliac vein obstruction produces venous hypertension at best and often leads to recurrent venous thrombosis. Therefore, it must be identified and corrected. A properly constructed AVF increases venous velocity through the previously thrombosed iliofemoral venous system without increasing venous pressure, thereby decreasing the risk of rethrombosis. Prolonged therapeutic anticoagulation is important to prevent recurrence.

The more recent modifications, which include balloon catheter thrombectomy of the vena cava during suprarenal caval balloon occlusion for nonocclusive caval clot and infrainguinal venous thrombectomy followed by early and continued postoperative anticoagulation through a catheter remaining in the posterior tibial vein and construction of an AVF, are likely to further improve outcome. The sequential details of the contemporary venous thrombectomy are described in the following sections.

Preoperative Procedures

1. Evaluate the patient for an underlying thrombophilia. Since the majority of patients with DVT do not develop this degree of extensive thrombosis, the likelihood of identifying an underlying thrombophilia is high. If the patient is already anticoagulated, blood is sent for antiphospholipid antibody, factor V Leiden, prothrombin gene mutation, and homocysteine. These can be reliably performed in patients who are already being treated with heparin. A blood sample also is sent for type and cross-match.

2. Delineate the full extent of thrombus. It is always important to know whether the clot is involving the vena cava. A contralateral iliocavagram frequently is performed to assess the vena cava (see Figure 45.1). Additionally, a rapid spiral CT scan with contrast of the chest examines for PE as well as thoracic pathology. The subsequent abdominal and pelvic CT scans during the same contrast infusion can identify the proximal extent of thrombus and any intraabdominal or pelvic pathology that may be etiologically associated with the DVT (see Figure 45.2). We have found PE in approximately 50% of our patients. We have also found renal cell carcinoma with tumor thrombus extending into the vena cava, adrenal tumors, retroperitoneal lymphoma, hepatic metastases from unknown primaries, and iliac vein aneurysms. Each of these is critically important for proper patient management and would have been overlooked had the CT scan not been performed.

Vena Tibial Prximal
FIGURE 45.1 Contralateral iliocavagrams showing nonocclusive thrombus in the vena cava illustrate the value of imaging to detect proximal extent of thrombus.29 Used with permission.
Nonocclusive Dvt
FIGURE 45.2 Asymptomatic PE (arrow, A) and renal cell carcinoma (arrow, B) identified with CT scan of chest as part of the evaluation of patients with iliofemoral DVT.29 Used with permission.

3. Therapeutic anticoagulation with unfractionated heparin (UFH) is initiated after the blood samples are drawn for the thrombophilia evaluation. Unfractionated heparin is continued throughout the procedure and postoperatively.

4. Vena caval filtration is not routinely required. An exception may be those patients with nonocclusive thrombus extending into the vena cava (see Figure 45.1). The recently introduced optional (nonpermanent) vena caval filters have been used with plans for early retrieval. Patients with caval thrombus also have been managed with balloon occlusion of the proximal vena cava at the time of balloon catheter thrombectomy. The protective vena caval balloon is

Venous Thrombectomy

FIGURE 45.3 Preoperative iliocavagram shows nonocclusive thrombus extending from the left iliofemoral venous system into the vena cava (A). A suprarenal balloon catheter was placed from the contralateral femoral vein and inserted under fluoroscopy. The balloon is inflated at the time of thrombectomy (B). Schematic of iliocaval thrombectomy performed with the double balloon catheter technique, protecting the patient from pulmonary embolism (C).15

FIGURE 45.3 Preoperative iliocavagram shows nonocclusive thrombus extending from the left iliofemoral venous system into the vena cava (A). A suprarenal balloon catheter was placed from the contralateral femoral vein and inserted under fluoroscopy. The balloon is inflated at the time of thrombectomy (B). Schematic of iliocaval thrombectomy performed with the double balloon catheter technique, protecting the patient from pulmonary embolism (C).15

positioned during preoperative iliocavagraphy from the contralateral femoral vein using fluoroscopic guidance. After positioning, the balloon remains deflated until the time of thrombus extraction (see Figure 45.3).

5. The operating room is prepared for fluoroscopy. An autotransfusion device is made available during the procedure.

Operative Details

6. General anesthesia is recommended for the majority of patients.

7. A longitudinal inguinal incision is made with exposure and control of the common femoral vein, femoral vein, saphenofemoral junction, and profunda femoris vein (see Figure 45.4A).

8. A longitudinal venotomy is made in the common femoral vein at about the level of the saphenofemoral junction. The precise location of the venotomy depends upon the extent and location of the thrombus. Since the common femoral vein is dilated, closure of the longitudinal venotomy with fine monofilament suture can be achieved without compromising vein lumen.

9. The infrainguinal venous thrombectomy is performed first. The leg is elevated and compressed from the toes proximally with a tightly wrapped rubber bandage. The foot is dorsiflexed and the leg squeezed and milked to remove the clot from below.

10. If infrainguinal clot persists, a cut-down on the medial portion of the lower leg is performed to expose the posterior tibial vein in order to accomplish a balloon catheter infrainguinal venous thrombectomy (see Figure 45.4B). A #3 or #4 balloon catheter is passed proximally from below to exit from the common femoral venotomy (see Figure 45.5A). The stem of a plastic IV catheter (12-14 gauge) is slid halfway onto the balloon catheter coming up from below and another (#4) balloon catheter is placed into the opposite end of the plastic sheath. Pressure is applied to the two balloons to secure the catheters inside the sheath by a single operating surgeon. The #4 balloon catheter is guided distally through the venous valves and clotted veins (see Figure 45.5B) to the level of the posterior tibial venotomy (see Figure 45.5C). The infrainguinal venous thrombectomy is then performed with a #4 or #5 balloon catheter, if necessary (see Figure 45.5D,E), repeating catheter passage as required until no further thrombus is extracted.

Iliofemoral Artery

11. Following the infrainguinal balloon catheter thrombectomy, the infrainguinal venous system is vigorously flushed with a heparin-saline solution to hydraulically force residual thrombus (which can be considerable) from the deep venous system by placing a #14-#16 red rubber catheter into the proximal posterior tibial vein and flushing with a bulb syringe (see Figure 45.6). After applying a vascular clamp below the femoral venotomy, the infrainguinal venous system is then filled with a dilute plasminogen activator solution using approximately 4 to 6 mg of rt-PA in 200 cc of saline. The plasminogen activator solution remains in the infrainguinal veins for the remainder of the procedure. If the infrainguinal venous thrombectomy is not successful due to chronic thrombus in the femoral vein, the femoral vein is ligated and divided below the profunda. Patency of the profunda is ensured by direct thrombectomy, if required.

12. The proximal thrombectomy is performed by passing a #8 or #10 venous thrombectomy catheter partway into the iliac vein for several passes to remove thrombus before advancing the catheter into the vena cava. The proximal thrombectomy is performed under fluoroscopy with contrast in the balloon, especially if a vena caval filter is present, there is clot in the vena cava, or resistance to catheter passage is encountered. The anesthesiologist should apply positive end-expiratory pressure during the iliocaval thrombectomy. If there is clot in the vena cava, the caval throm-bectomy can be performed with a protective balloon catheter inflated above the thrombus and the thrombectomy performed under fluoroscopy (see Figure 45.3).

13. After completion of the iliofemoral thrombectomy, the iliofemoral venous system is examined with intraoperative phlebography/fluoroscopy to ensure unobstructed venous drainage into the vena cava (see

Iliofemoral Venous System

FIGURE 45.5 Technique of infrainguinal balloon catheter venous thrombectomy begins with passage of a #3 or #4 balloon catheter from the posterior tibial vein proximally, exiting the femoral venotomy. A silastic IV sheath is placed halfway onto the catheter and another #4 balloon catheter inserted into the other end of the sheath (A). The balloons are inflated to fix the catheter tips inside of the sheath with pressure applied by a single individual guiding them distally through the clotted veins and venous valves (B). Catheters and sheath exit the posterior tibial venotomy (C). The thrombectomy catheter balloon is inflated gently as the catheter is pulled proximally (D) to exit the femoral venotomy, extracting thrombus (E).15

FIGURE 45.5 Technique of infrainguinal balloon catheter venous thrombectomy begins with passage of a #3 or #4 balloon catheter from the posterior tibial vein proximally, exiting the femoral venotomy. A silastic IV sheath is placed halfway onto the catheter and another #4 balloon catheter inserted into the other end of the sheath (A). The balloons are inflated to fix the catheter tips inside of the sheath with pressure applied by a single individual guiding them distally through the clotted veins and venous valves (B). Catheters and sheath exit the posterior tibial venotomy (C). The thrombectomy catheter balloon is inflated gently as the catheter is pulled proximally (D) to exit the femoral venotomy, extracting thrombus (E).15

Figure 45.7). Any underlying iliac vein stenosis is corrected with balloon angioplasty using a stent if venous recoil occurs. If a stent is used, a 12 mm diameter or greater is recommended.

14. After closing the venotomy with fine monofilament suture, an end-side AVF is constructed using the end of the proximal saphenous vein or a large proximal branch of the saphenous vein anastomosed to the side of the superficial femoral artery (see Figure 45.8A). The anastomosis should be limited to 3.5 to 4.0 mm in diameter. Frequently the proximal saphenous vein requires thrombectomy to restore patency prior to the AVF.

15. A piece of PTFE or silastic is placed around the saphenous AVF and a large permanent monofilament suture (#0) looped and clipped, leaving approximately

Teflon Silastic

FIGURE 45.6 A red rubber catheter (largest diameter possible) is placed into the posterior tibial vein and vigorously injected with a heparin-saline solution using a bulb syringe to flush residual thrombus. After flushing, the femoral vein is clamped and the leg veins injected with 150-200 cc of a dilute UK or rt-PA solution.15

FIGURE 45.6 A red rubber catheter (largest diameter possible) is placed into the posterior tibial vein and vigorously injected with a heparin-saline solution using a bulb syringe to flush residual thrombus. After flushing, the femoral vein is clamped and the leg veins injected with 150-200 cc of a dilute UK or rt-PA solution.15

Dilated Iliac Vein

After thrombectomy, After balloon dilation before balloon dilation

FIGURE 45.7 After thrombectomy, the right common iliac vein shows residual stenosis (A). Following iliac vein veno-plasty, the stenosis is corrected, restoring unobstructed venous drainage into the vena cava (B).29 Used with permission.

Venous Thrombectomy

FIGURE 45.8 The venotomy is closed with fine monofilament suture, and a 3.5-4.0 mm AVF is constructed sewing the transected end of the saphenous vein to the side of the superficial femoral artery. A piece of PTFE (5 mm graft) or similar wrap is placed around the saphenous AVF, looped with #0 monofilament suture and the ends clipped, leaving approximately 2-21/2 cm in the subcutaneous tissue to guide surgical closure of the AVF, should it be necessary (A). The distal posterior tibial vein is ligated. An infusion catheter (pediatric NG-tube) is brought into the wound through a separate stab wound in the skin and inserted and fixed in the proximal posterior tibial vein. The proximal posterior tibial vein and catheter is looped with #0 monofilament suture and fixed to the skin through a sterile button, which is used to snugly occlude the posterior tibial vein at the time of catheter removal (B).15

FIGURE 45.8 The venotomy is closed with fine monofilament suture, and a 3.5-4.0 mm AVF is constructed sewing the transected end of the saphenous vein to the side of the superficial femoral artery. A piece of PTFE (5 mm graft) or similar wrap is placed around the saphenous AVF, looped with #0 monofilament suture and the ends clipped, leaving approximately 2-21/2 cm in the subcutaneous tissue to guide surgical closure of the AVF, should it be necessary (A). The distal posterior tibial vein is ligated. An infusion catheter (pediatric NG-tube) is brought into the wound through a separate stab wound in the skin and inserted and fixed in the proximal posterior tibial vein. The proximal posterior tibial vein and catheter is looped with #0 monofilament suture and fixed to the skin through a sterile button, which is used to snugly occlude the posterior tibial vein at the time of catheter removal (B).15

2 cm in the subcutaneous tissue (see Figure 45.8A). This will guide future dissection in the event that operative closure of the AVF becomes necessary; however, most do not.

16. The common femoral vein pressure is measured before and after the AVF is opened. The venous pressure should not change. If the venous pressure increases when the AVF is opened, the proximal iliac vein should be reevaluated for residual stenosis or obstruction, and the proximal lesion corrected. If the pressure remains elevated, the AVF is constricted to decrease flow and normalize pressure.

17. If there appears to be notable serous fluid in the wound, a search for transected lymphatics is performed and they are ligated or coagulated. A #7 Jackson-Pratt drain (or other similar closed suction drain) is placed in the wound to evacuate blood clot and serous fluid that may accumulate postoperatively. The drain exits through a separate puncture site adjacent to the incision. The wound is closed with multilayered running absorbable sutures to achieve a hemostatic and lymphostatic wound closure.

18. The distal posterior tibial vein is ligated. An infusion catheter (typically a pediatric NG tube) is brought into the wound via a separate stab incision in the skin and inserted and fixed in the proximal posterior tibial vein (see Figure 45.8b). This catheter is used for postoperative heparin anticoagulation and a follow-up

Tibial Vein Blood Clot

(predischarge) phlebogram. This ensures maximal heparin concentration into the affected venous segment. A 2-0 monofilament suture is looped around the posterior tibial vein (and catheter) and both ends exit the skin. The ends of the suture are passed through the holes of a sterile button, which is secured snugly to the skin when the catheter is removed. This obliterates the proximal posterior tibial vein and eliminates the risk of bleeding following catheter removal. Prior to catheter removal, an ascending phlebogram is performed through the catheter to once again examine the veins phlebographically (see Figure 45.9).

19. Antibiotic ointment and sterile dressings are placed on the wounds. The patient's leg is wrapped with sterile gauze and multilayered elastic bandages from the base of the toes to the groin. The bandages are snugly applied, with the posterior tibial vein catheter exiting between the layers of the bandage on the lower leg.

Postoperative Details

20. Full anticoagulation is continued postoperatively with UFH through the catheter in the posterior tibial vein. The heparin solution and pump are attached to an IV

pole with wheels and the patient is allowed (encouraged) to ambulate. Oral anticoagulation is begun when the patient is awake and resumes oral intake. The heparin infusion is continued for a minimum of four to five days and the INR reaches 2-3.

21. Intermittent pneumatic compression garments are used on both legs during the postoperative period when the patient is not ambulating.

22. Prior to removing the posterior tibial vein catheter, a predischarge ascending phlebogram is obtained to evaluate patency of the femoropopliteal and iliofemoral venous segments. In the presence of an AVF, there may be significant washout of contrast in the common femoral vein, thereby mitigating good visualization of the iliac venous segments. Any significant stenosis in the iliofemoral venous segment should be treated to maintain unobstructed venous drainage into the vena cava.

23. Oral anticoagulation is continued for an extended period of time, at least one year in all patients and indefinitely in many.

24. Upon discharge the patient is prescribed 30 to

40 mmHg ankle gradient compression stockings and instructed to wear the stockings from the time he/she

ILIOFEMORAL (CAVAL) VENOUS THROMBOSIS

Rapid CT Scan with Contrast (Chest, Abdomen, and Pelvis)

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