Keywords
arteriosclerosis - stenosis - stenting - percutaneous transluminal angioplasty - critical
limb ischemia
Introduction
Critical limb ischemia (CLI) is a wearing condition characterized by insufficient
blood flow to the limbs due to arterial stenosis or occlusion typically associated
with peripheral artery disease (PAD). Worldwide the prevalence of PAD is estimated
to be over 200 million people, with 1–2 % suffering from CLI, thus showing the relevance
of this condition [1]. A standard classification used to categorize the grade of ischemia in PAD is the
Fontaine Classification: Stage I asymptomatic, Stage II intermittent claudication
(IIa walking distance > 200m; IIb walking distance < 200 m), Stage III ischemic rest
pain, Stage IV ulceration or gangrene or both [2].
In Germany, the prevalence of symptomatic PAD has been increasing with estimates suggesting
that up to 1.8 million individuals may be affected by the condition [3]
[4]. Early stages of PAD (Fontaine I and IIa) can be treated conservatively, while advanced
stages require interventional or surgical treatment. CLI presents as an advanced form
of PAD with Fontaine stages III and IV, and therefore typically presents as chronic,
severe pain, non-healing wounds, and can ultimately lead to limb loss if left untreated.
Furthermore, limb loss and cardiovascular events are more likely to occur in the short
term in individuals with CLI, than early stages of PAD [5].
In the past, open surgical procedures were the primary approach to managing PAD. However,
in recent years, we have seen an increase in endovascular interventional procedures.
These minimally invasive techniques, including percutaneous transluminal angioplasty
(PTA) and stenting, have gained prominence owing to their high safety profiles and
reduced invasiveness compared to traditional open surgery [6]
[7]
[8]
[9]. PTA entails the expansion of narrowed or obstructed arterial segments via catheter-based
techniques, while stenting involves the deployment of stents via catheters to preserve
the patency of arteries [10]. Both procedures have consistently demonstrated favorable outcomes in the restoration
of blood flow, effectively improving patient outcomes and relieving suffering [11]. While interventional procedures exhibit high success rates and good safety profiles,
it is essential to acknowledge that major complications, although infrequent, can
have profound consequences, potentially leading to extended hospitalization, increased
morbidity and mortality, and a significant reduction in the quality of life.
In Germany, medical facilities performing interventional radiological procedures in
association with the German Interventional Radiological Society (DeGIR) are encouraged
to document patient data by means of DeGIR's quality management system [4]. This system systematically and anonymously collects pre-, intra-, and post-operative
data, including complications and their respective levels of severity.
Despite the strides made in Germany's healthcare landscape, to date, a comprehensive
nationwide evaluation of the effectiveness and complication rates associated with
endovascular interventions for CLI within the country has not yet been performed.
This study thus aims to assess the success rates and major complications associated
with interventional radiological treatments for CLI. Specifically, this study is focused
on PTA and stenting procedures performed within Germany throughout the year 2021.
Moreover, the intent is to compare these findings with internationally published data,
thus providing a broader perspective on Germany's standing in the global landscape
of CLI management.
Materials and Methods
Study design
This study examines the safety and efficacy of the interventional treatment of CLI
in Germany in 2021, using data from the DeGIR quality management data system. The
technical/clinical success and major complication rates were the primary focus of
the analysis. Technical success was defined as the restoration of blood flow in the
area of the target lesion, by confirmed angiographic flow. The intervention was considered
clinically successful when symptom relief or improvement was reported immediately
intra-operatively or post-operatively until discharge from the clinic. Major complications,
as per SIR, encompass conditions that necessitate therapy with brief hospitalization
(< 48 h), demand significant intervention leading to an unplanned escalation in the
level of care and prolonged hospitalization (> 48 h), result in permanent adverse
sequelae, or ultimately lead to death [12].
Patient selection
This analysis includes data from patients who underwent endovascular treatments for
CLI in Germany in 2021with Fontaine stages III and IV. The data originates from the
quality management system managed by the German Interventional Radiology Society (DeGIR),
designed to gather information on interventional procedures, such as pre-, intra-
and post-operative data.
Statistical analysis
A retrospective descriptive analysis of DeGIR quality management system data was performed
to determine the efficacy and safety of interventional radiological treatments for
CLI. Microsoft Excel (Version 16.34, Microsoft, Redmond, WA, USA) was applied to determine
the effectiveness and rates of major complications, focusing on clinical and technical
success rates.
Results
The DeGIR quality management system recorded 16 393 PTA procedures in 208 different
hospitals, 701 stent procedures in 136 hospitals, and 8110 combined PTA/stent procedures
in 201 hospitals.
PTA
Among 16 393 patients treated by means of PTA for CLI, a technical success rate of
96.3 % and a clinical success rate of 92.33 % were reported ([Table 1]). The most frequent complications included distal embolization (0.48 %), major bleeding
(0.40 %), and aneurysm formation (0.19 %) ([Table 2]). Further complications were organ failure (0.08 %), cardiac decompensation (0.05 %),
intracranial bleeding (0.02 %), pulmonary dysfunction (0.012 %), and post-operative
infection/abscess (0.012 %). The lowest rates with 0.006 % were parenchyma ischemia,
organ damage under PTA, and drug side effects. Other complications were reported in
0.11 % of cases.
Table 1
Technical and clinical success rates of percutaneous transluminal angioplasty (PTA),
stenting, the combined intervention (PTA & stent), and overall rates in critical limb
ischemia in Germany 2021.
|
Success rates
|
PTA
(n = 16 393)
|
Stent
(n = 701)
|
PTA & stent
(n = 8110)
|
Overall
(n = 25 204)
|
|
Technical success (in %)
|
96.3
|
98.7
|
98.71
|
97.14
|
|
Clinical success (in %)
|
92.33
|
96.15
|
96.91
|
93.91
|
Table 2
Displayed are the frequent major complication rates of percutaneous transluminal angioplasty
(PTA), stenting, the combined intervention (PTA & stent), and overall rates in critical
limb ischemia in Germany 2021.
|
Major complication (rate in %)
|
PTA (n = 16 393)
|
Stent (n = 701)
|
PTA & stent (n = 8110)
|
Overall
(n = 25 204)
|
|
Major bleeding
|
0.40
|
1.28
|
0.54
|
0.47
|
|
Distal embolization
|
0.48
|
1.0
|
0.96
|
0.65
|
|
Aneurysm formation
|
0.19
|
0.43
|
0.19
|
0.20
|
|
Organ failure
|
0.08
|
–
|
0.06
|
0.07
|
|
Cardiac decompensation
|
0.05
|
0.29
|
0.11
|
0.07
|
|
Intracranial bleeding
|
0.02
|
–
|
–
|
0.01
|
|
Stent dislocation
|
–
|
–
|
0.07
|
0.02
|
|
Other
|
0.11
|
0.14
|
0.14
|
0.16
|
|
Overall
|
1.33
|
3.14
|
2.07
|
1.65
|
Stenting
Among 701 patients treated solely by stenting for CLI, a positive technical success
of 98.7 % and a clinical success of 96.15 % were reported ([Table 1]). The most frequent major complications were distal embolization (1 %), major bleeding
(1.28 %), and aneurysm formation (0.43 %) ([Table 2]). Further complications were cardiac decompensation (0.29 %,) and other complications
(0.14 %).
PTA/stent
In 8110 cases of combined PTA and stenting for CLI, a technical success rate of 98.71 %
and a clinical success rate of 96.91 % were observed ([Table 1]). The most frequent major complications were distal embolization (0.96 %), major
bleeding (0.54 %), and aneurysm formation (0.19 %) ([Table 2]). Cardiac decompensation and pulmonary dysfunction were reported in 0.11 % of cases.
Further complications were stent dislocation (0.07 %), organ failure (0.06 %), and
other complications (0.14 %).
Discussion
The results of the analysis of the DeGIR quality management system data in 2021 show
a high success rate and relatively low major complication rates for endovascular radiological
treatment of CLI by PTA and/or stenting procedures. The technical success rates for
both procedures exceeded 96 %, suggesting that these methods are efficient at treating
CLI. Clinical success rates were similarly high, which indicates that these methods
are also effective at relieving symptoms associated with CLI.
Current research has shown comparable results regarding complications and technical
success. Cardiovascular complication rates < 30 days after endovascular therapy for
CLI by Faber et al. were reported in 3.2 % of cases [11]. Farber et al. also found that in patients treated for critical limb ischemia who
had an adequate great saphenous vein, the incidence of major adverse limb events or
death was significantly lower in the surgical group than in the endovascular group. Based
on these results, a surgical strategy could also be considered in these patients [11]. Technical success for CLI treatment has previously been reported as minimum 92 %
[13] and 90 % [14]. Additionally, a systematic review and meta-analysis showed a technical PTA success
rate of 91.1 % in 44 studies [15]. Furthermore, a Cochrane systematic review reported the technical success to be
93.7 % and 97.6 % for PTA and stenting, respectively. The Cochrane review also showed
procedural complications in 7.4 % of PTA procedures and 6.3 % of stenting procedures
[16].
Major complication rates were under 1.3 % across all three categories of procedures,
which suggests that they have a good safety profile. The most common complications
were distal embolization and major bleeding, both of which are known complications
of interventional radiological procedures [16]
[17]
[18]. The overall low complication rates reflect positively on the quality and safety
of these treatments. The results also showed that a combined PTA and stenting procedure
had a higher technical and clinical success rate compared to PTA and stenting alone.
A previous systematic review found similar results and explained this finding by the
fact that stenting in addition to PTA can resolve PTA-associated complications [16].
However, this study is not without limitations. The retrospective study design limits
the ability to control confounding variables or establish causality. The voluntary
nature of DeGIR system reporting and potential reporting biases could impact the validity
of findings. Additionally, regional differences in data input, coupled with incomplete
or missing entries, influence data accuracy [19]
[20]. Nevertheless, this is the first study of its kind in Germany evaluating endovascular
treatments for CLI on a nationwide scale. A previous study analyzing the DeGIR quality
database highlighted the importance of follow-up data to fully draw a conclusion on
the efficacy of interventions [21]. In the future quality assessment should be extended by this point of interest.
Lastly, only data from 2021 was included in this study, which may not fully represent
long-term trends for CLI treatment. Despite these limitations, the findings of this
study provide valuable insights into the nationwide effectiveness and safety of interventional
radiology treatment for CLI in Germany and will help to identify areas for improvement.
In conclusion, treatment of critical limb ischemia by PTA and/or stenting procedures
by interventional radiologists in Germany is effective and safe. The results are consistent
with published international data and suggest a trend towards surpassing international
benchmarks. A study of this size can potentially contribute to the establishment of
international/national quality standards for the management of critical limb ischemia.
In future studies, it is important to keep track of the outcomes over a longer period
of time by observing patients at 30 days, 6 months, and ideally for up to 1 year.
This will give further information on the long-term effects and results of the treatments
combined with initial high operative success rates and low complication rates.
-
The study approves the high efficacy and safety of radiological endovascular treatments
for critical limb ischemia in Germany.
-
For clinicians, this study affirms that their therapeutic approaches in critical limb
ischemia are both effective and safe.
-
The study offers a clear view on the effectiveness of current practice, provides a
benchmark for future interventions, and potentially shapes guideline recommendations.
