PresentedYaounde, Cam2010;21.

PresentedSwitzerland So10, 2010. Abs

1DepartmeCameroon.

2DepartmeCameroon.

3DepartmeCameroon.

4DepartmeCameroon.

674

Patients Characteristics and Outcome of 518Arteriovenous Fistulas for Hemodialysis ina Sub-Saharan African Setting

Marcus Fokou,1 Gloria Ashuntantang,2 Abel Teyang,1 Francois Kaze,2 Alain Chichom Mefire,3

Marie Patrice Halle,4 Fru Angwafo III,1 Samuel Takongmo,5 and Wilhelm Sandmann,6,7

Yaounde, Douala, and Limbe, Cameroon; D€usseldorf and Kamp-Lintfort, Germany

Background: To present the particular aspects of arteriovenous fistula (AVF) for hemodialysisin sub-Saharan Africa in terms of patients’ characteristics, patency and complication rates, aswell as factors influencing them.Methods: From November 2002 to November 2009, 518 fistulas were constructed on adults.Demographic data, patency, and complications were analyzed. The association between age,sex, and comorbidities (HIV, hypertension, diabetes) on one hand and complications as wellas AVF patency on the other was sought.Results: Males represented 73.7% of the patient population, and the mean age of the popula-tion was 45.3 years. As far as etiologies of end-stage renal disease (ESRD) and comorbiditiesare concerned, chronic glomerulonephritis was the leading cause of ESRD (134; 25.9%), fol-lowed by hypertension (22.3%), although prevalent in 83.2% of patients, and diabetes(20.1%), although prevalent in 22.2%. No cause for the ESRD could be identified in 89 patients(17.2%). Only 20.64% had AVF as the initial vascular access. The main types of AVF con-structed were radiocephalic (68%) and brachiocephalic (24.9%). The median follow-up periodwas 275 days. The cumulative patency rate at 1 year and 2 years was 76% and 51%, respec-tively. Altogether, 188 complications occurred in 16% of the AVFs. Aneurysms, failure to mature,and thrombosis were the most frequent complications occurring in 27.65%, 14.89%, and 10.63%of cases, respectively. The management options for the complications included the creation ofa new access for 63 complications (33.51%) and nonoperative management in 44.14% of thecases. We found no adverse effect of comorbid factors like diabetes mellitus (c2 ¼ 3.58, P >0.05) and HIV-positive status (c2 ¼ 0.64, P > 0.05) on the complications rate.Conclusion: According to our patients’ characteristics, there is a possibility of constructing AVFon nearly every hemodialysis patient with a good outcome.

at the 7th Congress of the Cameroon Cardiac Society,eroon, March 18, 2010. Abstract in Cardiovasc J Afr

at the Joint Congress of German, Austrian, andcieties of Vascular Surgery, Berlin, Germany, Septembertract in Ao3.3.1.4 Gef€aßchirurgie 2010;15:379.

nt of Surgery, Yaound�e General Hospital, Yaounde,

nt of Medicine, Yaound�e General Hospital, Yaounde,

nt of Medicine, Douala General Hospital, Douala,

nt of Surgery, Limbe Regional Hospital, Limbe,

5Department of Surgery, Yaound�e University Hospital Centre,Yaound�e, Cameroon.

6Centre for Vascular Surgery and Kidney Transplantation, Univer-sity of D€usseldorf, D€usseldorf, Germany.

7Vascular Centre, Kamp-Lintfort Hospital, Kamp-Lintfort,Germany.

Correspondence to: Marcus Fokou, MD, Department of Surgery, TheYaound�e General Hospital, BP 5408 Yaound�e, Cameroun; E-mail:mfokou@yahoo.com

Ann Vasc Surg 2012; 26: 674–679DOI: 10.1016/j.avsg.2011.07.019� Annals of Vascular Surgery Inc.Published online: January 27, 2012

Vol. 26, No. 5, July 2012 Aspects of AVFs for hemodialysis in Sub-Saharan Africa 675

INTRODUCTION

Since the advent of hemodialysis in 1944, and the

subsequent use of arteriovenous fistulae (AVFs) as

a long-term vascular access,1 there has been a drastic

increase in both the availability of hemodialysis and

long-term survival of patients with chronic renal

failure. This has resulted in permanent vascular

access procedures in dialysis (AVFs, prosthetic arte-

riovenous grafts, and autologous vein grafts)

becoming the most common operations performed

by vascular surgeons. Because of data illustrating

superiority of AVF in terms of patency rates, lower

complication rate, and lower costs, it has been rec-

ommended in countries such as United States that

AVF should be constructed in at least 50% of

patients on chronic hemodialysis.2 This goal has

even been raised to 65% in recent guidelines.3

In developing countries and particularly in sub-

Saharan Africa, there are very few reports concern-

ing vascular access surgery4,5 compared with North

Africa6,7, as hemodialysis is not yet widespread in

these areas. In Cameroon, since the year 2000,

hemodialysis is accessible to many. Therefore,

construction and maintenance of vascular accesses

has become a challenge.

In this report, we present the particularities of AVF

for hemodialysis in our setting. Specifically, we

sought to audit the patients’ characteristics, the

complications, patency rates, and todetermine factors

that affect these outcomes. To the best of our knowl-

edge, this is the largest published report concerning

vascular access surgery in sub-Saharan Africa.

METHODS

We retrospectively evaluated upper-limb AVFs per-

formed between November 2002 and 2009 at the

Yaound�e General Hospitalda university teaching

hospital with most modern facilities for vascular

surgery and hemodialysisdin Cameroon. The cases

included in the study were consecutive adult

patients with end-stage renal disease (ESRD)

referred for the creation of AVF (8 patients aged

<16 years were not considered for this study).

Primary (firstly created) and secondary (all subse-

quently constructed) AVFs were included for evalu-

ation. Outpatient and inpatient hospital records

were reviewed. All the patients underwent preoper-

ative general and local examination according to the

recommended reporting standards. The general

evaluation was aimed at identifying comorbid

conditions, such as heart failure, peripheral arterial

disease, stroke, diabetes mellitus, and high blood

pressure; medical history; and vascular access

history. The local evaluation was focused on the

potential access site. It included the following steps:

1) brachial pressures; 2) examination of the skin to

exclude lesions or scars on the site; 3) vein examina-

tion using a tourniquet or a blood pressure cuff to

ascertain the distensibility, continuity, and

compressibility; 4) palpation and Doppler explora-

tion of the radial, brachial, and ulna arteries. At

the end of this procedure, a decision on the

following was made: 1) the patient’s suitability for

surgery; 2) type of AVF to be performed: radioce-

phalic (RCAVF), brachiocephalic (BCAVF), brachio-

basilic, or cubitobasilic; and 3) the need for

a treatment (treatment of heart failure, sepsis,

severe anemia, or skin infection) before surgery. A

preoperative ultrasonography was mandatory only

in obese patients or in cases of a secondary fistula

with a poor venous visibility.

In our practice, we start first by placing a wrist

RCAVF on the nondominant arm, if anatomically

favorable. From there, we moved to a BCAVF. Our

next choices are a RCAVF and then a BCAVF on

the dominant arm. The brachiobasilic AVF and the

other possibilities are realized as last alternative.

All the operations were performed by the two

vascular surgeons of the team either as an ambula-

tory or a 1-day hospital stay procedure. Local anes-

thesia with 1% lidocaine was used for every patient.

Operative details, such as the quality of veins and

the perioperative complications, were noted by the

surgeon. The thrill and a hand-held Doppler were

used for perioperative quality control. The postoper-

ative management included analgesics and dressing

every 4 days. Patients were advised to avoid exerting

pressure or any compression on the upper limb. No

venous punctures or blood pressure measurements

with inflatable cuffs were permitted on the upper

limb concerned.

Follow-up visits with the vascular surgeon were

scheduled (two times during the first week and

then weekly during the first month postopera-

tively). Dressings, suture removal, and assessment

of fistula patency by physical examination were

done during these visits. The fistulas were allowed

to mature for a minimum of 4 weeks. If maturation

was not achieved 3 months after surgery, this was

considered as a failure to mature. The decision on

the first puncture of the access was jointly taken

by the attending surgeon and the nephrologists.

Postoperative complications were followed up by

the surgeon and the nephrologists. Functionality

was determined by the ability to access the fistula

for hemodialysis. Complications were graded

according to the time of occurrence as immediate

(within 48 hours after the surgery), early (before

676 Fokou et al. Annals of Vascular Surgery

first puncture or within the first 30 days after

surgery), and late (after 30 days). The seriousness

of the complications was also evaluated. Complica-

tions were considered to be severe when they led

to the loss of the access, to be moderate when

surgical or endovascular intervention was required

to save the fistula, and to be mild when no surgical

management was necessary.

The end points were the death of the patient, final

fistula failure, or failure of patient to turn up for

follow-ups. Statistical analysis was done using the

Epi-info 6 (Redmond, WA). Categorical data were

compared using c2 test, nominal data were

compared using Student t test, and the statistical

significance was set at a P < 0.05. Patency rate was

determined by KaplaneMeier curve.

RESULTS

Sociodemographic Data

During the 7-year study period, 518 upper-arm

vascular accesses were created on 492 limbs on

478 patients. Of these, 382weremales, representing

73.7% of the population. Two patients who relo-

cated overseas for kidney grafting were not included

in this analysis. The mean age of the patients at time

of surgery was 45.33 (range: 17e74) years.

As far as etiologies of ESRD and comorbidities are

concerned, chronic glomerulonephritis was the

leading cause of ESRD (134; 25.9%), followed by

hypertension (22.3%), although prevalent in

83.2% of patients, diabetes (20.1%), although prev-

alent in 22.2%, and HIV (5%), although prevalent

in 51 (9.84) of patients. No cause for the ESRD could

be identified in 89 patients (17.2%).

A history of previous permanent access (AVF,

graft) was found in 6.7% of the patients at presenta-

tion. At the time of AVF creation, 411 of patients

(79.34%) were undergoing dialysis through

a temporary venous catheter. In cases of subclavian

catheter, they were located on the side opposite to

the limb of the AVF in 70% of the cases. The dura-

tion of catheter carriage ranged from 20 to 214

days, with a mean of 79.83 days.

A corrective treatment was necessary in 6% of

the patients before surgery. This included mainly

blood transfusions and medical treatment of heart

failure. A preoperative vascular ultrasonography

was necessary to trace the veins in 2% of patients

(all of whom were obese).

Operative Data

Only native AVFs were constructed. No grafts were

placed. The distribution of AVFs showed 357

RCAVFs (68.91%), 129 BCAVFs (24.9%), and

approximately 6% for the other anatomical types

(Table I). Perioperative quality control demon-

strated a 97.8% success rate on first attempt. Perio-

perative exploration showed that 8% of veins were

not very suitable. In these cases, a dilatation with

heparinized saline as well as with dilators and selec-

tive obliteration of venous side branches were

done. However, in 3%, another vein segment was

chosen. Approximately 86% of AVFs were created

on the nondominant arm. Among those located

on the dominant arm, 5% were firstly constructed

AVFs.

Follow-up

The median follow-up period was 275 days, ranging

from 6 months to 7 years. Outcomes were catego-

rized as functioning, death, and complicated, as

defined in our Methods section.

Arteriovenous fistula patency rate was 76% and

51% at 1 and 2 years, respectively. Figure 1 repre-

sents the 3-year survival curve.

The time to first cannulation varied from 17 to

180 days, with a median of 31 ± 15 days.

There was no association between sociodemo-

graphic factors, comorbidities studied, type of AVF,

time to first cannulation, and catheter carriage on

the patency of AVF. HIV status did not also have

an adverse effect on the patency. On the contrary,

most of patients died with functioning fistulas.

During the follow-up period, among the AVFs

successfully constructed, 16% experienced one or

more complications. The total number of complica-

tions was 188, which are listed in Table II. Primary

failure (failure to mature) and aneurysmal forma-

tion were the most common complications. The

complication rate was not statistically significant

among the different types of AVF.

No adverse effect of the following patients’ char-

acteristics on the frequency of complications was

found: age, gender, time to first cannulation, and

length of catheter carriage. Furthermore, 46 of the

188 complications occurred in diabetic patients

(c2¼ 0.88, P> 0.05) and 15 in HIV-positive patients

(c2 ¼ 1.16, P > 0.05).

Complications were classified as immediate in 24

(12.82%), early in 44 (23.40%), and late in 74.10%

of cases. Failure to mature, hemorrhage, and aneu-

rysms were themost common complications seen in

the early, immediate, and late groups, respectively.

Severe complications were encountered in

35.89% of the cases. These weremainly thrombosis,

severe andmultifocal stenosis, multifocal or infected

aneurysms, and pseudoaneurysms. Minor and

Table I. Types of AVF realized

Variable Number %

RCAVF 357 68.91

BCAVF 129 24.90

BBAVF 26 5.01

CBAVF 6 1.15

AVF, arteriovenous fistula; BB, brachiobasilic; CB, cubitobasilic;

RC, radiocephalic; BC, brachiocephalic.

Fig. 1. KaplaneMeier patency curve of the arteriove-

nous fistula.

Table II. Different types of complications

Complication Number %

Aneurysm 52 27.65

Failure to mature 2 14.89

Hematoma/hemorrhage 24 12.27

Stenosis 20 10.63

Thrombosis 20 10.63

Ischemia 12 6.38

Collateral veins dilation 12 6.38

Infection 8 4.25

Cardiac insufficiency 8 4.25

Major edema 4 2.13

Total 188

Vol. 26, No. 5, July 2012 Aspects of AVFs for hemodialysis in Sub-Saharan Africa 677

moderate complications occurred in 43.58% and

20.5% of the cases, respectively.

The management options for our complications

were mainly conservative. The creation of a new

AVF as a definitive therapeutic decision was done

in 33.15% of cases.

DISCUSSION

The proportion of patients commencing dialysis

with an AVF was only 20.65%, whereas 79.35%

initiated dialysis with temporary central venous

catheter. The late presentation of patients with

ESRD for specialized care (owing to late referral

from nonspecialized centers, geographical distance,

ignorance, and low income) has been described

earlier in our setting.8 This late presentation at end

stage with uremic complications requires emer-

gency renal replacement therapy.8,9 Therefore,

central venous catheters are inevitable. In Nigeria,

Nwankwo et al. reported the use of catheters for

vascular access in most (91%) of the patients in

a cohort of 179 patients over a 5-year period.4 A

proportion of 92.8% and 86.3% catheter use was

also described in Ivory Coast10 andMorocco, respec-

tively.6 It is also interesting to mention that in most

sub-Saharan African countries, catheters will

constitute the only access modality owing to the

lack of vascular surgeon. On the contrary, in

western countries, there is a large variation in the

proportion of patients who commence hemodialysis

through an AVF versus catheters in favor of AVF in

Europe and catheter in the United States without

a sound scientific explanation.11e14

If we consider the goal of 65% native AVF for

patients entering into a hemodialysis program set

by the U.S. National Kidney Foundation guide-

lines,3 we still have room for improvement. This

improvement is, however, dependent on several

factors, including a sound prevention program for

chronic kidney disease, which will enable early

detection and appropriate care of persons with this

condition to avoid late diagnosis, late presentation,

and unprogrammed dialysis.

The duration of catheter carriage in our patients

at the time of surgery was 79.83 days, meaning

that the time from dialysis onset to fistula creation

is lengthy. The explanations for this lie in the long

period of nephrological care necessary to improve

on the state of these patients who present late.

Furthermore, most patients pay for the procedure

out of their pocket owing to the absence of a health

insurance policy. Finally, dialysis subsidies in the

country do not cover vascular access. Identical prob-

lems were also raised in other dialysis facilities in

sub-Saharan Africa.4e7,10

We succeeded in creating a fistula in nearly every

patient on chronic hemodialysis. Currently, the

prevalence of AVF versus graft in dialysis patients

is variable among countries. Our figures are largely

above the ultimate goal of ‘‘prevalent functional

AVF placement rate greater than 65% of patients’’

set up in guideline number 8.1.3 Apart from the

difficulties in affording prosthetic materials,

although they are available, and the high infectious

risk, the difference in patient characteristics could

explain the low need of prosthetic grafts in our

678 Fokou et al. Annals of Vascular Surgery

population. While the mean age of chronic dialysis

patients in Europe and United States is approxi-

mately 70 years, the mean age of our population

was <50 years. More so, although diabetes mellitus

with its inherent vascular complications accounts

for a major part of patients on renal replacement

therapy in the developed world, we still have

chronic glomerulonephritis prevalent in our popu-

lation.9 In western countries, because enough

health care is provided, there is also an aggressive

approach to indiscriminately draw blood and use

intravenous lines. These aforementioned factors

greatly affect the vascular integrity of patients and

make the creation of native fistulas difficult. The

samemay apply to other sub-Saharan African coun-

tries.4e7,10 Another specific hypothesis is that our

dialysis program was for <10 years, and within

this period, the vein sites for an AVF were not yet

exhausted for a patient.

The distribution of the type of AVF showed a great

proportion of RCAVF, which is the generally recom-

mended AVF and the most constructed in the

majority of current surgical works.11,14e16 On the

contrary, some authors, such as Mc Lafferty

et al.17 and Martin et al.,18 reported a high propor-

tion of BCAVF without a particular explanation.

The mean time to first cannulation in our study

group was 40 days. Actually, the best time for the

maturation of a fistula is not clearly defined and

differs among dialysis teams, from <28 days to 96

days.10 Hemodynamic studies addressing this issue,

such as those conducted by Le Blanc et al.14 and

other authors,18 led to the conclusion that after 4

weeks, a BCAVF was hemodynamically ready to

maintain a sustainable dialysis. In our experience,

4 weeks after the operation, most of the fistulas

are already well ‘‘arterialized.’’

The cumulative patency rate of 76% at 1 year and

51% at 2 years is not different from the figures in

many countries. A patency of 3 years is a reasonable

goal for a fistula.3 In our team, our aim was to

achieve an 80% patency at 1 year and >60%

patency at 2 years.

As far as complications are concerned, our overall

complication rate of 16%, including the frequency

and management of the different types, is difficult

to compare, as the issue is not addressed by most

of the reports dealing with vascular access.19,20 In

the U.S. National Kidney Foundation guidelines,

for example, no threshold was set that can be used

as a quality indicator, as setting a goal may

discourage native AVF construction in patients

with complex vascular anatomy.2,3 Primary

failure continues to be a major obstacle, with stud-

ies reporting values ranging from 25% to

43%.11,12,17,21 With regard to the different types of

complications, the paucity of the surgical literature

makes discussion difficult. Only a few reports have

addressed the management of aneurysms22,23 or

some specific complications, such as ischemia.24,25

Unlike some reports, we did not find a poorer fistula

patency rate or a higher complication rate in dia-

betic and elderly patients, as has been reported in

some studies,15,26,27 perhaps because of the rela-

tively young age of our patients and the relatively

lowprevalence of diabetes. EvenwithHIV, a relation

not yet analyzed by current surgical literature, an

adverse effect on the fistula outcome was not

noticed.

CONCLUSION

In this study, we reported our 7-year experience in

vascular access surgery in a setting where access to

prosthetic graft is seldom, and showed that in nearly

every patient with the same characteristics, it is

possible to construct an AVF in the course of dialysis

with a good outcome. There were no effects of HIV

status on the outcome of the fistula. Although not

specifically analyzed, we think there is a positive

effect of low income and insurance status in the

effort to always try to construct a native AVFda

policy that can be implemented in patients from

same socioeconomic conditions.

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