Access for Dialysis: Surgical and Radiologic Procedures - part 2 pdf

29Primary Arterio-Venous (Native) Fistulas (PAVF) 3 intimal rupture and subsequent thrombosis. Frequent use of 1% topical lidocaine will help to prevent and reverse vasospasm. Extend the arteriotomy to the appropriate length (8-10 mm), matching the vein using fine Dietrich scissors (Fig. 3.10C). Take the appropriate needle of the previously placed proximal double-armed 7-0 polypropylene corner suture and suture inside out to the proximal arterial corner. Have the assistant dilate the artery using a Blue Darter forceps for exact suture placement and to keep from catching the back wall with the suture (Fig. 3.11). The corner bites should be small (approximately 1 mm). Tie the suture in three square knots. Correctly placed, the knot is on the outside of the vessel (Fig. 3.12A). Place the second double-armed polypropylene suture in similar fashion to the distal arterial corner, but do not tie the suture at this time (Fig. 3.11). This helps to expose the back wall while placing the first 2-3 proximal sutures (Fig. 3.12). An artery or vein may be closest to the surgeon, depending on which side of the arm the surgeon prefers to sit. The running suture is begun at the back wall in the proximal corner. The very first stitch is placed from outside-in on the vessel closest to the surgeon (Fig. 3.12A). The purpose of this first stitch is just to get inside the vessel with the needle passing as close to the corner knot as possible. Alternatively, Fig. 3.9. The two corner stitches are used to keep the vein and the patch oriented at all times. 30 Access for Dialysis: Surgical and Radiologic Procedures 3 one may pass the suture (the needle) between the back walls and then place the first stitch out-in on the vessel next to the surgeon (Fig. 3.12B). The first back wall suture and all subsequent back wall sutures go inside-out on the opposite vessel and outside-in on the vessel nearest the surgeon (Fig. 3.12C). In these illustrations, the surgeon is on the ulnar site closest to the radial artery. The stitches closest to each corner are placed taking small bites (1 mm) of the vessels with minimal travel. This will maximize blood flow and preserve lumen size by preventing a purse-string effect. Large bites in the corners jeopardize the very survival of the fistula. No rough handling of the vessels is permissible. Forceps may Fig. 3.10A, B. Techniques for dilating and local heparinization of the radial artery. C: The arteriotomy is extended to match the size of venous patch. A B C 31Primary Arterio-Venous (Native) Fistulas (PAVF) 3 be used to push and direct vessels during suturing, but not to grasp. The intima should never be picked up by forceps. The only acceptable grabbing is of the perivas- cular loose connective tissue using fine forceps. After the first 2-3 back wall stitches have been placed, the distal arterial corner stitch is tied, or this suture can be left untied under slight tension until the back wall is completed. In either case, this suture is attached to a rubber-shod clamp hanging over the patient’s hand. This gives the appropriate tension and lines up the back walls nicely for precise suturing. Every stitch is strategically placed to maximize the fistula size and resultant blood flow (Fig. 3.13A). The last stitch of the back wall goes inside-out on the vessel away from the surgeon (Fig. 3.13B). If not done before the distal corner stitch is now tied in three knots (sutures a & b) (Fig. 3.14A). One end is rubber-shod and the other end is used to tie to the back wall suture (suture c) using 6-7 square knots (Fig. 3.14B). These last two tied su- tures are then cut. Start in either corner and run the anterior wall (Fig. 3.15A). The first 2-3 stitches should be double bites while the assistant gently dilates the vessels with a Blue Darter forceps. When the anterior anastomosis is halfway complete, this suture is rubber-shod. Then start the suture from the other corner (Fig. 3.15B), to meet midway on the anterior wall. If the surgeon runs both sutures toward himself, the very last stitch may be reversed so that the knot can be tied across the anterior wall (mainly an aesthetic point). Fig. 3.11. By using the sharp microforceps to dilate the artery, exact stitching is facilitated. 32 Access for Dialysis: Surgical and Radiologic Procedures 3 Fig. 3.12. A) The first stitch of the back wall anastomosis goes outside-in on the vessel closest to the surgeon. B) Alternatively, this stitch can be placed after passing under- neath the vein patch. C) All subsequent stitches are single bites through the back wall anastomosis. If a Heifet’s clamp was placed on the vein, it is removed now. The distal arterial Heifet’s clip is removed, and then the proximal arterial clip is released. There is always slight bleeding from the suture lines at this time. Even if the bleeding seems significant, simply apply gentle pressure for a few minutes. Unless there is a technical mishap along the suture line, the bleeding will stop. A serious mistake often made immediately after removal of the vascular clamps is to start placing extra sutures to stop small bleeding points from needle holes. Figure 3.16 shows an overview of a “patch” cephalic vein PAVF. Often, however, there is no suitable dorsal branch. Figure 3.17 illustrates the steps for an end-of-vein to side-of-artery without “patch.” The principal technique is identical to the patch A B C 33Primary Arterio-Venous (Native) Fistulas (PAVF) 3 Fig. 3.13A. The back wall running suture. Fig. 3.13B. The very last stitch of the back wall anastomosis. 34 Access for Dialysis: Surgical and Radiologic Procedures 3 steps. However, because of the absence of the patch, exact suturing technique be- comes even more important. Also, placing the corner stitches before dividing the vein to keep orientation is imperative (Figs. 3.17C-D). All suturing techniques de- scribed above for the patch PAVF apply. When the bleeding has stopped, the vessels should be examined for strictures (from fibrous bands or vasospasm). Topical 1-2% lidocaine and judicious cutting of fibrous bands with microscissors will resolve these problems. There is often pro- nounced spasm in the vein at the level immediately beyond the point where the dissection stops. Be sure that the vein makes a smooth curve, and then gently spread or cut along the vein for another 1-2 cm. A sponge soaked in lidocaine in contact with the vein for a few minutes will usually relieve the vasospasm. Finally, make sure the entire wound is absolutely dry before skin closure. Fig. 3.14. Technique for tying the distal corner sutures. 35Primary Arterio-Venous (Native) Fistulas (PAVF) 3 Fig. 3.15. A: Completion of the front wall anastomosis. B: The proximal and distal sutures are tied midway. 36 Access for Dialysis: Surgical and Radiologic Procedures 3 Two or three subcutaneous sutures may be placed, avoiding suturing over the vein. The authors prefer subcuticular (5-0 polyglactin) skin closure with steri-strips and a loose dressing applied. A circular or even semi-circular tightly taped wound covering may obstruct fistula flow and cause hand edema. The patient is encouraged to elevate the arm resting on pillows and to make fists over a soft ball to prevent swelling. Complications of Primary AV Fistulas Early problems after PAVF placement are often related to surgical/technical fac- tors and include thrombosis, postoperative bleeding, infection, hand ischemia (“steal”) and paresthesia from peripheral nerve injury during anesthesia or surgery. Late complications are usually related to dialysis practice and needle puncture technique. The most common are vascular stenosis at various levels, thrombosis, usually starting at a stenosis site, infection/inflammation usually in association with thrombosis, false aneurysm at the anastomosis site, infiltrating hematoma after di- alysis needle puncture, true aneurysm along the vein and venous hypertension in the hand. Early Complications Thrombosis is the most common early complication. The incidence depends on the criteria (i.e., the quality of vessels, usually the vein) used for placement of PAVF. One should, however, always suspect a technical problem such as a kinked or twisted vein, problem with suturing, compressing hematoma, a too tight subcutaneous clo- sure with edema, preexisting unrecognized proximal venous occlusion or a dressing that is too tight. Sometimes, thrombosis occurs at the anastomosis within a few days of operation. Most often, the vein is patent proximal to the clotted anastomosis. The fistula should be explored since the problem, if found, can usually be corrected. However, one may alternately find thickened, inflamed vessels which place the Fig. 3.16. Overview of the “patch” primary AV fistula technique. 37Primary Arterio-Venous (Native) Fistulas (PAVF) 3 fistula at risk for rethrombosis after repair. Moving the anastomosis 2-3 cm proxi- mally in order to use unaffected tissue and vessels is recommended. Kinks and rotations of the vein must be corrected. This requires taking down the anastomosis, properly aligning the vessels and carefully re-anastomosing the vessels. Again, if the vessels show signs of inflammation, one is better off creating a new anastomosis. A more proximal and unrecognized, preexisting venous stenosis (usually from previous needle punctures) can be assessed with a Fogarty catheter (#3-5) or smooth dilators (#3-5) if they will reach. Some surgeons routinely pass a Fogarty catheter during the initial surgery to ensure an adequate vein all the way to the antecubital fossa. If there is no adequate passage, and assuming the artery is of size and quality deemed likely to result in a successful fistula, another form of vascular access should be considered such as a straight polytetrafluoroethylene (PTFE) graft from the dis- tal radial artery (already exposed). If the adequacy of the artery is in question, it is Fig. 3.17. Techniques for preparing the cephalic vein without patch technique. The length of the venotomy is determined by the local anatomy, including the angle between the vein and artery. The suturing technique is identical to that described for the patch anas- tomosis. 38 Access for Dialysis: Surgical and Radiologic Procedures 3 wiser to place a loop PTFE AV graft with both anastomoses in the antecubital fossa (Chapter 4). Postoperative bleeding is uncommon and requires exploration if continuous or in the case of expanding hematoma. A small anastomotic bleed will usually require a carefully placed 7-0 polypropylene suture. Exact suturing is facilitated with a neuro-suction held by the surgeon’s left hand, while the suture is placed with the needle driver in the right hand. Only when the surgeon can see the bleeding hole in the suture line can an exact stitch be placed. This may be obvious only for a fraction of a second, and the coordination between the surgeon’s left (suction) hand and right (suture) hand is critical. A larger bleed from an anastomotic defect will require clamping of the artery. Bleeding from other sites is addressed accordingly. A sloppy ligature on the distal vein(s) may produce profound acute bleeding requiring compression and explora- tion. Minor bleeding or oozing can be stopped by a bipolar electrocautery. He- matoma formation causing compression of the vein may result in thrombosis. Infection is and should be extremely uncommon. Every attempt should be made to save a well-functioning fistula using common surgical principles and judgment. Late infections along the vein are uniformly related to dialysis needle puncture technique. Hand ischemia (“steal”) is caused by reversal of blood flow through the radial artery away from the hand. This complication is less common with primary AV fistulas than with PTFE grafts (Chapter 4). However, the treatment is simple and consists of suture ligating the radial artery distal to the AV anastomosis using perma- nent sutures (Fig. 3.18). This increases pressure and thereby flow to the palmar arch of the hand from the ulnar artery. The diagnosis of arterial steal is made from clini- cal examination, but should also include duplex Doppler ultrasonography to obtain flow determinations and finger pressures before and after manual occlusion of the artery distal to the anastomosis. Based on duplex Doppler measurements and finger pressures, there will always be evidence of some arterial steal with any type of AV fistula. However, clinical symptoms such as pain, coolness and tingling are quite uncommon after PAVF. Differential diagnoses include nerve damage (from radial nerve compression during surgery or related to axillary block anesthesia), distal embolization and carpal tunnel syndrome. Late Complications Vascular stenosis can occur at any level. Often, it is seen in the cephalic vein 1-2 cm from the anastomosis. Even though this can be corrected with a vein or PTFE patch angioplasty, it is most appropriate to create an entirely new anastomosis a few centimeters up the artery as illustrated in Figure 3.19A. A stenosis further up the vein can be corrected by a patch angioplasty (Fig. 3.19B) or a graft interposition (Fig. 3.19C), depending on length, severity and other anatomical considerations, as well as the surgeon’s preference. Thrombosis can also occur at any level along the vein. In fact, it often starts at a stenosis site. Therefore, the development of a venous stenosis often precedes throm- bosis formation. If the thrombosis occurs at the anastomosis and the proximal vein is still open, treatment consists of re-anastomosing the fistula a few centimeters up the artery as described in Figure 3.19A. A thrombosed primary AV fistula may also be declotted and the stenosis corrected with a patch or interposition graft. Another option is to utilize radiographic interventional techniques with t-PA and balloon [...]... the patient should undergo a venogram to Access for Dialysis: Surgical and Radiologic Procedures, 2nd ed., edited by Ingemar J.A Davidson 20 02 Landes Bioscience 46 4 Access for Dialysis: Surgical and Radiologic Procedures determine the extent of the process, as well as its suitability for balloon angioplasty (which should be done in the same setting) or surgical repair (bypassing the stenosis) The surgeon... affects the thumb and causes pain, bluish discoloration and eventually ulceration 44 Access for Dialysis: Surgical and Radiologic Procedures 3 Fig 3 .22 This upper arm PAVF had an estimated 6 L/min blood flow before “banding.” Selected References 1 2 3 Humphries Jr AL, Nesbit Jr RR, Caruana RJ et al Thirty-six recommendations for vascular access operations: Lessons learned from our first thousand operations... along the vein and have the assistant cut with a knife or fine scissors (Fig 4.5) If there is no assistant, a similar technique is used with a fine forceps and scissors This technique for dissection is identical for both arteries and veins, and was 48 Access for Dialysis: Surgical and Radiologic Procedures 4 Fig 4 .2 The skin incisions and intended loop configuration in relation to the forearm anatomy... and corrected if and when significant symptoms develop It must be remembered that an AV fistula is the patient’s lifeline and any surgical intervention may potentially result in fistula failure requiring further access procedures and acute placement of dual lumen catheters or PTFE grafts One should exercise great judgment and err toward the conservative side 3 42 Access for Dialysis: Surgical and Radiologic. .. toward the conservative side 3 42 Access for Dialysis: Surgical and Radiologic Procedures Summary Steps in Primary AVF Creation 1 2 3 4 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Mark radial artery and cephalic vein and dorsal branch Skin incision between the radial artery and cephalic vein Dissect cephalic vein and the dorsal branch Place vessel loops Cut through the fascia on top of the... Amer Surg 1981; 47:4 Burger H, Kluchert BA, Koostra G et al Survival of arteriovenous fistulas and shunts for haemodialysis Eur J Surg 1995; 161: 32 7-3 34 Katsumata T, Ihashi K, Nakano H et al An alternative technique to create end-of-vein to side-of-artery fistula for angioaccess J Amer Coll Surg 1996; 1 82: 6 9-7 0 CHAPTER 1 CHAPTER 4 PTFE Bridge Grafts Ingemar J.A Davidson, Illustrations: Stephen T Brown... considerations for PTFE grafts are outlined in Chapter 2 The correct, atraumatic surgical technique is the key for short- and long-term graft patency Early graft failure (thrombosis and infection) before the graft has been used, is likely the result of poor surgical technique and debilitating patient circumstances, i.e., HIV infection, diabetes, preexisting infectious conditions, intravenous drug abuse and obesity... type, which the authors currently use and prefer, is a sheath tunneler Again, for the loop access placement the semicircular type is preferred (bottom, Fig 4.7) This tunnel device consists of three parts, a semicircular sheath containing a rod to which a bullet or head is screwed (attached) during the subcutaneous tunnel 52 Access for Dialysis: Surgical and Radiologic Procedures 4 Fig 4.6 Detailed anatomy... more appropriate and is easier to close (Fig 4.11A) A mosquito hemostat is placed at the very tip of the 4 mm end to keep this portion of the graft away from the operating field 4 Access for Dialysis: Surgical and Radiologic Procedures Fig 4. 12 Vascular clamps are placed on all venous branches and a small venotomy is created (A) The vein is gently dilated and heparinized locally (B) and the venotomy... with and have used three types of tunneling devices (Fig 4.7) First, is the so-called Noon tunneler (top of Fig 4.7), which is essentially a 6 mm dilator at either end of a 25 cm long flexible steel rod The graft is tied to one end and pulled through in a semi-circular movement 50 Access for Dialysis: Surgical and Radiologic Procedures Fig 4.4A Static retractors of this type are sometimes needed 4 Fig . technique to create end-of-vein to side-of-artery fistula for angioaccess. J Amer Coll Surg 1996; 1 82: 6 9-7 0. CHAPTER 1 CHAPTER 4 Access for Dialysis: Surgical and Radiologic Procedures, 2nd ed., edited. judg- ment and err toward the conservative side. 42 Access for Dialysis: Surgical and Radiologic Procedures 3 Summary Steps in Primary AVF Creation 1. Mark radial artery and cephalic vein and. 3.11. By using the sharp microforceps to dilate the artery, exact stitching is facilitated. 32 Access for Dialysis: Surgical and Radiologic Procedures 3 Fig. 3. 12. A) The first stitch of the