需要订阅 JoVE 才能查看此. 登录或开始免费试用。

Summary

We present a modified no-touch technique (MNTT) to create a radio-cephalic arteriovenous fistula (RC-AVF) in which the venous and arterial wall avoid devascularization and the radial artery does not sever.

Abstract

Autologous arteriovenous fistula (AVF) is the primary and best option to obtain vascular access for hemodialysis treatment; other options are arteriovenous graft (AVG) and central venous catheterization (CVC). The implementation of radio-cephalic autologous arteriovenous fistula (RC-AVF) in the forearm was preferred among patients with superior vascular conditions. However, there is a high rate of early fistula failure. The chosen surgical method is understood to have an effect on the maturation of the fistula. New surgical procedures such as radial artery deviation and reimplantation (RADAR) have been significantly improved for juxta-anastomotic stenosis. Nevertheless, new problems such as stenosis of arteries and narrowing of surgical indication were also found. In this report, we presented a modified no-touch technique (MNTT) to create an RC-AVF, in which the venous and arterial wall avoid devascularization and the radial artery does not sever.

Introduction

Radio-cephalic autologous arteriovenous fistula (RC-AVF) have been regarded as the primary and best choice for vascular access in hemodialysis patients^1,2. However, the early failure to mature continues to be a major problem with RC-AVF creation³. Different surgical methods have different degrees of vascular injury and affect the maturation of RC-AVF. In 1996, Souza⁴ first proposed the use of a no-touch technique (NTT) to separate the great saphenous vein in coronary artery bypass grafting and achieved good results^5,6,7. Horer et al.⁸ was the first to use NTT to construct RC-AVF. At the 1-year follow-up, primary patency was 54% and secondary patency was 80%. Sadaghianloo et al.⁹ further extended the concept of no-touch technology and proposed the radial artery deviation and reimplantation (RADAR) technique. This technique is associated with less juxta-anastomotic stenosis. However, the inflow artery stenosis was more prominent with RADAR. We speculate that this may be related to the severance of the radial artery and skeletonization of the distal tip of the artery.

To further reduce the injury to veins and arteries during the operation, we proposed a new modified no-touch technique (MNTT), which significantly improved the patency rate and the fistula maturation¹⁰. The aim of this technique was to primarily avoid both devascularization of the venous and arterial wall and severing of the radial artery. After the skin and subcutaneous tissue were incised, the cephalic vein and its surrounding adipose tissue were seen below the superficial fascia. An 8-10-mm-long incision was made in the superficial fascia and cephalic vein wall, and the radial artery pedicle (including the radial artery and its accompanying veins) was isolated 40-50 mm. The artery pedicle was not severed, and the radial artery pedicle was raised to approach the cephalic vein. An 8-10-mm-long incision was made in the artery. The anastomosis was performed side-to-side and the distal vein was ligated to form a functional end-to-side anastomosis (Figure 1).

We evaluated blood vessels by Doppler ultrasound before the surgeries of 10 cases: there was no stenosis in the radial artery and cephalic vein with radial artery diameter≥1.6 mm and cephalic vein diameter≥2 mm. Echocardiography showed left ventricular score >60%, and the patient had no surgical contraindications. A distance of <2 cm between the artery and vein was identified as the proposed anastomosis site.

Figure 1. Schematic diagram of anastomosis types in AVFs¹². a: Conventional surgery for an AVF. b: AVF created using the NTT. c: AVF created using the MNTT and a functional end-to-side anastomosis. AVF: arteriovenous fistula; NTT: no-touch technique. Please click here to view a larger version of this figure.

Protocol

The MNTT was conducted according to the human research protocol approved by the ethics committee of the Affiliated Suzhou Science & Technology Town Hospital of Nanjing Medical University (IRB2021029).

1. Preoperative evaluation

1. Check the medical history: Ensure that the patients have no coagulation abnormalities, valvular heart disease, congestive heart failure, peripheral vascular disease, skin disease, history of central venous catheterization, history of pacemaker implantation, neck and chest trauma, or surgical diseases.
2. Perform physical examination results: Ensure symmetrical blood pressure in both upper limbs, good arterial pulse, strong pulsation, negative Allen test¹¹, good venous distensibility after binding the tourniquet, no edema or varicose veins in the upper limb, and no previous central or peripheral venous scars.
3. Perform comprehensive assessment of the forearm vasculature of the patient's operative limb by color Doppler ultrasound.

2. Disinfection and anesthesia

1. Place the patient in the supine position with external rotation and abduction of the operative upper limb.
2. Perform routine iodophor disinfection, draping, and local infiltration anesthesia with 1% lidocaine.

3. Superficial fascia exposure

1. Make a 4-cm skin incision (longitudinal incision) at a distance of <2 cm between the radial artery and the cephalic vein of the forearm, and ensure it is relatively close to the cephalic vein.
2. Separate the subcutaneous adipose tissue using curved hemostatic forceps to expose the superficial fascia. Look for the presence of the cephalic vein and its surrounding tissues below the superficial fascia (Figure 2a). Do not open the superficial fascia in this step and do not use the electric knife to stop the bleeding.

4. Preparation of the cephalic vein

1. Ensure that below the exposed superficial fascia, the cephalic vein (including part of the vasa vasorum) and its surrounding adipose tissue could be clearly seen.Make two tunnels along the direction perpendicular to the cephalic vein. The tunnel openings should be located >1 cm from both sides of the cephalic vein.
2. Pull the cephalic vein close to the radial artery by two blue vessel loops passing through the tunnels at each end to facilitate surgical suturing (Figure 2b).

5. Preparation of the radial artery

1. Cut the tissue layer by layer to expose the radial artery pedicle (including the radial artery and its accompanying veins on both sides) in the pulsating area of the radial artery that can be reached with the index finger. Ligate the small artery branches and pick out the radial artery pedicle with the hemostatic forceps. Dissect the radial artery pedicle for about 40-50 mm.
2. Pass the two red vessel loops through each end of the radial artery pedicle. The radial artery could be pulled to be closer to the cephalic vein to facilitate the surgical suture (Figure 2c).

6. Opening the cephalic vein and the radial artery

1. Place a vascular clamp along the tunnel at both ends of the cephalic vein to block the cephalic vein blood flow. Place a vascular clamp at each end of the pedicle to block arterial blood flow.
   NOTE: Although vascular clamps were used to block blood flow, the intact tissue is preserved around the cephalic vein, which plays a better protective role for the vessels.
2. Pull the red vessel loops to bring the radial artery pedicle closer to the cephalic vein, and an incision is made on the lateral wall corresponding to the radial artery and cephalic vein.
3. Lift the superficial fascia at the cephalic vein gently with micro-forceps and cut the superficial fascia and the wall of the cephalic vein with a micro-scissor or sharp knife. The incision length should be about 8-10 mm.
   NOTE: Do not touch or mobilize the vein outside this incision.
4. Open the arterial sheath and the wall of the radial artery successively to make an 8-10-mm-long incision with a sharp knife and microscopic scissors, taking care not to twist the vessel. The incision is in the lateral wall of the artery.
   NOTE: Do not touch or mobilize the artery outside this incision.
5. Gently rinse the cephalic vein and radial artery with heparin saline solution (25 IU/mL) to remove any blood or blood clots.

7. Functional end-to-side anastomosis

1. Use the 7.0 non-absorbable single-strand suture to establish vein-arterial anastomosis (side-to-side) with the Kunlin's technique (Figure 2d, e). Suture the posterior wall of the vessel first, and then suture the anterior wall of the vessel. Pull the vessels close to each other to reduce vascular tension.
2. Open the blood flow and ligate the distal cephalic vein to form a functional end-to-side anastomosis (Figure 2f).
3. Ensure that no obvious bleeding is detected in the surgical field and use a mattress suture for surgical incision.

Figure 2. Surgical steps of the modified no-touch technique. a: Exposure of the cephalic vein with the surrounding tissue in situ. b: Placing the blue vessel loop. c: Exposure of the radial artery and its companion vein. d: A side-to-side anastomosis using the Kunlin's technique. e: Anastomosed the posterior wall of the vessel. f: The distal cephalic vein was ligated to form a functional end-to-side anastomosis. Please click here to view a larger version of this figure.

Representative Results

Since January 2021, we have applied the MNTT technique in 10 patients to construct AVF. Seven of the 10 patients have been under dialysis.

None of the patients had fever or infection after surgery. Physical examination of the cephalic-vein at weeks 4 and 8 showed significant dilation. Fistula can be palpable tremor with loud murmur. Doppler ultrasonography showed obvious dilation of the cephalic vein and radial artery. The blood flow spectrum of the cephalic vein 1.5 cm away from the anastomosis showed spiral laminar flow (Figure 3). The fistula constructed by MNTT can be punctured repeatedly with two needles. Blood flow of the brachial artery was >600 mL/min (Table 1). Four hours of hemodialysis was successfully completed. None of the patients had any current vascular access-related complications.

Figure 3. Postoperative ultrasound results. a: Juxta-anastomotic region. b: Spiral laminar flow was shown at the outflow tract vein and radial artery. c: Cephalic vein. d: Blood flow of cephalic vein (5 cm from the anastomosis). e: Blood flow of radial artery (1.5 cm from the anastomosis). f: Blood flow of brachial artery (elbow fossa). Please click here to view a larger version of this figure.

Table 1: Ultrasound results of the patient 4 and 8 weeks after RC-AVF surgery Please click here to download this Table.

Discussion

Venous juxta-anastomotic stenosis is one of the main factors affecting the maturation of AVF⁵. It is known to be closely related to intimal hyperplasia^13,14,15. However, prevention strategies for intimal hyperplasia are still limited. Modified surgical procedures¹⁶ such as RADAR have been shown to have less venous juxta-anastomotic stenosis, increased maturation and patency, and fewer secondary interventions^9,17. However, the inflow artery stenosis was more prominent with RADAR.

Here, we extended the RADAR technique and avoided devascularization of the venous and arterial wall and did not sever the radial artery. The results showed a significant reduction in venous stenosis, and no arterial stenosis was observed. Spiral laminar flow was shown on the blood-flow spectrum of the cephalic vein 1.5-cm from the anastomosis. The blood flow of the brachial artery was >600 mL/min. In the postoperative follow-up, we found that the patients did not have pain, ischemia, numbness, and other adverse problems in the distal forearm. These improved outcomes suggest that MNTT is likely the preferred surgical technique to perform AVF.

The first critical surgical step was exposure of the superficial fascia. The cephalic vein and its surrounding tissues below the superficial fascia could be seen clearly. Care should be taken not to damage the superficial fascia, and an electric knife should not be used to stop bleeding. The second critical surgical step was preparation of the radial artery. By bringing the cephalic vein and radial artery close together, we can achieve suturing. In the procedure of artery isolation, the arterial pedicle (artery and two veins) was dissected for 4-5 cm. The farther the distance between the artery and the vein, the longer the arterial pedicle needed to be dissected. In the 10 cases of RC-AVF that we completed with MNTT, the distance between the artery and the vein was up to 2 cm.

The advantages of this technique are listed here. The cephalic vein and radial artery were not skeletonized at the site of anastomosis. The aim of MNTT is primarily to avoid devascularization of the venous and arterial wall. The artery pedicle was not severed. MNTT is applicable to a wide range of patients (forearm and upper arm fistulas).

There are limitations associated with the technique. First, based on our experience, the operation cannot be performed if the distance between the cephalic vein and radial artery >3 cm. Second, despite the protecting the perivascular tissue, anastomosis is still needed with a vascular clamp to block blood flow.

There is a wide range of surgical indications without severing the artery. In our experience, MNTT is suitable for snuffbox, forearm, and upper arm fistula surgery.

We confirmed that MNTT can be used to create RC-AVF, and the short-term follow-up outcomes were satisfactory. A larger sample size is still needed to evaluate the long-term efficiency and applicability of this technique.

Materials

Curved hemostatic forceps	Xinhua Surgical Instrument Co., Ltd.	ZH131R/RN
Dissecting Forceps	Xinhua Surgical Instrument Co., Ltd.	ZDO25R/RN
Electrotome	Changzhou Yanling Electronic Equipment Co., Ltd.	TY21205812
Eyelld Retractor	Xinhua Surgical Instrument Co., Ltd.	Z014602T
Lidocaine	Hebei Tiancheng Pharmaceutical Co., Ltd.	1B200612104
Halsey needleholder	Xinhua Surgical Instrument Co., Ltd.	ZM208R/RN
Micro forceops	Xinhua Surgical Instrument Co., Ltd.	ZD275RN/T
Micro needle holder forceps	Xinhua Surgical Instrument Co., Ltd.	ZF2618RB/T
Micro scissors	Xinhua Surgical Instrument Co., Ltd.	ZF022T
Micro vessel knife	Xinhua Surgical Instrument Co., Ltd.	ZF1549RN
Non-absorbable suture 3-0	Ethicon,LLC	SA84G
Poly propylene 7-0	Ethicon,LLC	PDB601
Sharp blade	Suzhou Medical Products Factory Co., Ltd.	TY21232001
scalpel handle	Shanghai Medical Instrument (Group) Co., Ltd. Surgical Instruments Factory	J11030
Syringe with needle (5ml)	BD medical devices (Shanghai) Co., Ltd	2006116
Triangle needle	Hangzhou Huawei medical supplies Co., Ltd	7X17
Vessel clamp	Xinhua Surgical Instrument Co., Ltd.	ZF220RN
Vessel loop	Shenzhen Yiman Technology Co., Ltd	EM-SR1