Repeated venipuncture as a reason of aneurysm and pseudoaneurysm of vascular access

The most complications of the vascular access are: thrombosis, aneurysm, infection. Aneurysms can be either true, containing all layers of a venous wall, or false (pseudoaneurysm), lined by brous tissue and thrombosis. Aneurysm dilatation is one of the major complications of vascular access. The incidence increased with the duration of the usage, repeated puncture at the same or nearby site, and increased intraluminal pressure of the graft. We present an uncommon case in which aneurysm and pseudoaneurysm of the native stula is caused by puncture, in both sides. Repeated punctures at the same site, may progressively weaken the venous wall resulting in dilation of the outow vein. A 68- year-old Albanian women had been in a hemodialysis program for 4 years, using a left brachiocephalic stula. The inow artery, outow vein, and the deep veins were examined in detail. During the study period the patient have had three surgeries, for aneurysm of hemodialysis access on one hand, and for pseudoanurysm of hemodialysis access on the other hand. But, even that the patient survived and everything went well. The idea of our paper was that in patients we have predisposition for the formation of aneurysm and pseudoaneursym, the medical staff have more frequent meetings, so that such cases are treated more specically, with more frequent visits to vascular surgeon, with more frequent measurements of draining vein diameter and ow of vascular access. The K/DOQI guidelines recommend a regular program of monitoring and surveillance of the vascular access. Color Doppler ultrasound s considered a valuable tool in the preoperative evaluation and in the follow-up.


Introduction
The most complications of the vascular access are: thrombosis, aneurysm, infection. Aneurysms can be either true, containing all layers of a venous wall, or false (pseudoaneurysm), lined by brous tissue and thrombosis.
Aneurysm dilatation is one of the major complications of vascular access. The incidence increased with the duration of the usage, repeated puncture at the same or nearby site, and increased intraluminal pressure of the graft. Surgical intervention is indicated where there is expansive growth with a diameter greater than 2cm and rupture or impending rupture (1,2,3,4) .
It is therefore, not advisable to puncture the same spot repeatedly. For these reason the super cialized arterial segment should be long enough to allow an adequate selection of sites for puncture.
Aneurysmorrhaphy is indicated for small aneurysms, with the diameter smaller than 2 cm, although excision followed by interposition of vascular graft is often required for larger ones. Pseudoneurysm occur at the site of needling/puncture or at the anastomosis (2,4,5,6,7) .

Material And Methods
A 68-year-old Albanian women had been in a hemodialysis program for 4 years, using a left brachiocephalic stula. The in ow artery, out ow vein, and the deep veins were examined in detail.
For reconstruction of the native arteriovenous stula, the minimum diameter of artery and vein had to be >2mm. While in terms of aneurysm, different authors de ne it as dilatation to more than three times the native vessel diameter, with the minimum size being 2cm.
The in ow artery and the out ow vein were examined by duplex ultrasound scan with linear transducers of 7-15 MHz. The aneurysm size was 3.3cm, with excellent function, othervise asymptomatic and the time to treatment from the creation of the AVF was 4 years.
Reason for reparing the aneurysm were skin changes with thinnig and erosion, with bleeding, in ammation, pain, oedema, a shortened area of cannulation, impossible to canulate because of risk of spontanoeus rupture ( g.1).
No oedema or collateral venous circulation was present. The patient underwent reconstruction of the same stula, with resection of the 2.5cm of cephalic vein and aneurysmorraphy of the cephalic vein. A long lateral incision overlying the cephalic vein was performed, managing aneurysm excision ( g.2).
After six months of using the stula patient have had an cerebrovascular insult, after which she went on Unit of Intensive Care with hypotension and loss of consciousness. As a result of this the stula thromboses. The patient has a central venous catheter placed in femoral vein. After the improvement of the general condition of the patient, the right brachio-cephalic stula was created, because the left basilic vein was very weak in diameter. Everything went well and after 6 weeks the stula was ready for puncture, patient did regular hemodialysis three times per week.
After three months of use, patient came urgent in Emergency Room from the local hemodialysis center, with severe pain and oedema of the right arm, that happened after needling/puncture of the stula ( g.3).
On physical exam we found out skin thinning and shiny atrophic skin, large pulsatile mass, with thrill on right arm, above cubital fossa, which was indication for next surgery ( g.4).

Discussion
One third of arteriovenous stulas develop complications including thrombosis (51.6%), stenosis (22.6%), aneurysm formation (6.7%) and infection (6.5%). Risk factors for these complications include: hypotension, hypertension, early puncture of the AVF, repeated puncture in the same site, external mechanical compression for hemostasis after removing needling. Pseudoaneurysm maybe thought as hemathomas communicating with the lumen of the access, which with time can develop a brotic sac (1,3,6,7,8) .
If an aneurysm has ruptured or there is a risk of imminent rupture (skin ulceration and infection), like in our case, emergency ligation of the aneurysm is required.
We present an uncommon case in which aneurysm and pseudoaneurysm of the native stula is caused by puncture, in both sides. Repeated punctures at the same site, may progressively weaken the venous wall resulting in dilation of the out ow vein.
Therefore it is demonstrated that even in long term AVF with aneurysm and pseudoaneurysm after needling it is advisable to try to salvage the access. At our patient we improved the quality of hemodialysis and no other venous segments or graft prothesis were used for the access salvage.
According to the Kidney Disease Outcomes Quality Initiative (KDOQI) recommendations, the stula with a native ideal vein must present at least 6 mm in diameter and ow superior to 600 mL/min, and be at a depth of 0.5 to 1 cm of the skin.
After the surgery, has presented some problems that we solved immediately, tryng to avoid the need for a central venous catheter. The patient is feeling good, still performing the hemodialysis on her native stula, on right side. We recommend her to change the needling site each time she perform hemodialysis.
To avoid loss of access and to prevent disartrous complications, the National Kindney Foundation Disease Outcomes Quality Initiative guidelines recommend that cannulation of the aneurysmal vein should be avoided. In our case, even thought the patient had aneurysmal out ow vein, she remained stable and asymptomatic, without compromising hemodialysis at all, till erosion and bleeding happened.
She was afraid to loss her vascular access, therefore she was reluctant to notify the vascular surgeon despite the recommendation of the nephrologist (8,9,10,11,12) .
Alternative treatment modalities for aneurysm of AVF inckude: excision and primary anastomosis, open plication with sutures and stapling devices to re-fashion the aneurysm and reduce the volume of the sac, excision and interposition of venous or prostethic graft, and ligation of access when patient have had renal transplantation. Some authors suggest ballon angioplasty for stenosis in some segments of out ow vein away from aneurysmal part.
Alternative treatment modalities for pseudoaneurysm of AVF include: thrombin injection or ultrasound compression for small pseudoaneurysms and surgical repair for large pseudoaneurysms to prevent local complications or enlargement.
Some patients may have a predisposition to aneurysm formation. We considered this as a possible condition to our patient, so we after surgery recommend needling sites changed and blunt needles used if possible (3,4,7) .
There are several important factors and conditions to consider in maintaining long term function of the vascular access. It is very important to maintain a normal volume status. It is well known that hypotension from dehydration is one of the most common causes of thrombosis of vascular access.
Local factors also contribute to thrombosis of vascular access, including mispuncturing and formation of hematomas, compression of hematoma, repuncturing with the same neddle causes contamination.
Antiplatelet drugs such as dipyridamole, ticlopidine and prostaglandins may be used to prevnt thickening of the intima and occlusion of the draining vein (6,8,9,11) .
The idea of our paper was that in patients we have predisposition for the formation of aneurysm and pseudoaneursym, the medical staff have more frequent meetings, so that such cases are treated more speci cally, with more frequent visits to vascular surgeon, with more frequent measurements of draining vein diameter and ow of vascular access. The K/DOQI guidelines recommend a regular program of monitoring and surveillance of the vascular access. Color Doppler ultrasound s considered a valuable tool in the preoperative evaluation and in the follow-up. Also, patients due to the general aggravated condition, receive a lot of parenteral therapy, which mainly nurses of hemodialysis patients should take into account, not to damage the large veins which in the future will be used to realize the vascular access.

Declarations
No con ict of interest.
No funding.

Consent
The patient signed an informed consent document to participate and provided her permission regarding publishing her data and photographs.