How can you estimate the risk of renal failure following contrast angioplasty

Source:

  1.  Mehran R, Aymong ED, Nikolsky E, et al. (2004). “A simple risk score for prediction of contrast-induced nephropathy after percutaneous coronary intervention: development and initial validation”. J. Am. Coll. Cardiol. 44 (7): 1393–9. doi:10.1016/j.jacc.2004.06.068PMID 15464318.

You can do that using a simplified scoring system as follows (tested mainly on coronary angioplasty though): [ excel file is provided also)

Risk Factors:
  • Systolic blood pressure <80 mm Hg – 5 points
  • Intraarterial balloon pump – 5 points
  • Congestive heart failure (Class III-IV or history of pulmonary edema) – 5 points
  • Age >75 y – 4 points
  • Hematocrit level <39% for men and <35% for women – 3 points
  • Diabetes – 3 points
  • Contrast media volume – 1 point for each 100 mL
  • Renal insufficiency:
    • Serum creatinine level >1.5 g/dL – 4 points
or
    • 2 for 40–60 mL/min/1.73 m2
    • 4 for 20–40 mL/min/1.73 m2
    • 6 for < 20 mL/min/1.73 m2
Scoring:
5 or less points
  • Risk of CIN – 7.5
  • Risk of Dialysis – 0.04%
6–10 points
  • Risk of CIN – 14.0
  • Risk of Dialysis – 0.12%
11–16 points
  • Risk of CIN – 26.1*
  • Risk of Dialysis – 1.09%
>16 points
  • Risk of CIN – 57.3
  • Risk of Dialysis – 12.8%

do you expect to have similar stroke rate if you operate on a nice talkative active person and on a tired non-talkative and inactive one? is it your technical skills that determines the risk of stroke?

Reference:
http://stroke.ahajournals.org/content/early/2014/04/30/STROKEAHA.113.003956.abstract

Activities of Daily Living Is a Critical Factor in Predicting Outcome After Carotid Endarterectomy in Asymptomatic Patients

  1. James G. Reeves, MD

Stroke, STROKEAHA.113.003956


NOT REALLY!!!! 
This study showed THREE times risk of stroke when the patient is dependent preoperatively! If you see such a patient, never quote your outcome for stroke; but rather quote three times your figures .. and be careful: how much benefits you expect to achieve if you operate on this patient: balancer it carefully to be on the safe and correct side.
Here are their findings:
Of 19 748 CEAs, 19 348 (97.97%) were functionally independent, 377 (1.99%) were functionally partially dependent, and 23 (0.12%) were functionallydependent. 

In functionally independent group, there were 196 (1.01%) strokes, 84 (0.43%) deaths, and 1416 (7.17%) other complications, 

whereas in the functionally partially dependent group, there were 14 (3.71%) strokes, 10 (2.65%) deaths, and 80 (21.22%) other complications. 

In multivariable risk-adjusted model, using functionally independent as reference, functionally partially dependent was associated with death (odds ratio, 3.3; 95% confidence interval, 1.6–6.8; P<0.001), stroke (odds ratio, 3; 95% confidence interval, 1.7–5.4;P<0.001), and other complications (odds ratio, 2.5; 95% confidence interval, 1.9–3.2; P<0.001).

How active claudicants are usually? can you depend on them to do the structured exercises?

source of discussion:

Physical Activity Monitoring in Patients with Intermittent Claudication
G.J. Laureta, b, H.J.P. Fokkenrooda, b, B.L. Bendermachera, M.R.M. Scheltingac, d, J.A.W. Teijinka, b, Corresponding author contact information,
EJVES June 2014

The answer is: No, they are not active at all … and they are therefore likely to fail in any advice for self exercising (it appears)!!

their conclusions:

Methods

Before initiating treatment, 94 patients with newly diagnosed IC and 36 healthy controls were instructed to wear a tri-axial seismic accelerometer for 1 week. Daily PA levels (in metabolic equivalents, METs) were compared with the ACSM/AHA public health PA minimum recommendations (≥64 METs·min·day, in bouts of ≥10 minutes). A subgroup analysis assessed the effect of functional impairment on daily PA levels.

Results

Data from 56 IC patients and 27 healthy controls were available for analysis. Patients with IC demonstrated significantly lower mean daily PA levels (±SD) than controls (387 ± 198 METs·min vs. 500 ± 156 METs·min, p = .02). This difference was solely attributable to a subgroup of IC patients with the largest functional impairment (WIQ-score < 0.4). Only 45% of IC patients met the public health physical activity guidelines compared with 74% of the healthy controls (p = .01).

Conclusions

More than half of patients with IC do not meet recommended standards of PA. Considering the serious health risks associated with low PA levels, these findings underscore the need for more awareness to improve physical exercise in patients with IC.

would you fight to get a Hyperbaric oxygen in difficult to heal diabetic foot ulcers, or would you consider primary amputation?

source of discussion:

Hyperbaric Oxygen for the Treatment of Diabetic Foot Ulcers: A Systematic Review
R.M. Stoekenbroeka, Corresponding author contact information, E-mail the corresponding author, T.B. Santemaa, D.A. Legematea, D.T. Ubbinka, A. van den Brinka, b, M.J.W. Koelemaya

EJVES June 2014

Their conclusions:

Two RCTs in patients with ischaemic ulcers found increased rates of complete healing at 1-year follow-up (number needed to treat (NNT) 1.8 (95% CI: 1.1 to 4.6) and 4.1 (95% CI: 2.3 to 19)), but found no difference in amputation rates. A third trial in ischaemic ulcers found significantly lower major amputation rates in patients with HBOT (NNT 4.2, 95% CI: 2.4 to 17), but did not report on wound healing. None of the RCTs in non-ischaemic ulcers reported differences in wound healing or amputation rates. Two trials with unknown ulcer types reported beneficial effects on amputation rates, although the largest trial used a different definition for both outcomes. HBOT did not influence the need for additional interventions.

Conclusion

Current evidence shows some evidence of the effectiveness of HBOT in improving the healing of diabetic leg ulcers in patients with concomitant ischaemia. Larger trials of higher quality are needed before implementation of HBOT in routine clinical practice in patients with diabetic foot ulcers can be justified.

This is very interesting topoic. Looking on the table and results, the trials did show a significant difference in the healing rate for a fairly low NNT; but interesting enough, this didn’t reflect on the final amputaion rate (minor or major) that significantly. But who said that the amputation is only related to wound healing?
So the answer to the question above is: yes, use it if available; there is some good evidence for its benefits; but don’t get over excited!

are you happy to expose the whole leg for a vein to be harvested, or would you consider mini-invasive endoscopic vein harvest?

reflection on:

Endoscopic Vein Harvesting in Lower Extremity Arterial Bypass: A Systematic Review

Well; the results are certainly NOT ENCOURAGING: the endoscopic harvesting is damaging the vein and is reducing the patency, SIGNIFICANTLY!!!
Any increased effect on infection rate: nop!!

See their results:

We identified 18 cohort studies and case series, with considerable clinical heterogeneity, including 2,343 patients. Meta-analysis of six studies revealed a significantly reduced rate of primary patency after EVH (hazard ratio 1.29, 95% confidence interval [CI] 1.03–1.63), with no significant difference between EVH and OVH with respect to wound infection in 12 studies (odds ratio 0.81, 95% CI 0.61–1.08). There was a lack of strong evidence to support the secondary outcomes of EVH.


HOWEVER, I am still UNHAPPY with slicing the leg like this … Is there any thing creative, please?? 

Would you operate on intermittent claudicants?

discussion source:

Invasive Treatment for Infrainguinal Claudication Has Satisfactory 1 Year Outcome in Three out of Four Patients: A Population-based Analysis from Swedvasc. EJVES June 2014

using the Swedish registry, some 775 patients were identified who underwent intervention for claudication (IC). Those are their results: 
Improvement at 1 year was seen in 567 (73.2%) patients, (225 [77.6%] in the open surgery group, 320 [71.6%] in the endovascular treatment group, and 22 [57.9%] in the hybrid treatment group). 
No significant difference was found between the open surgery and endovascular treatment groups comprising 737/775 patients (p = .350). 
Hybrid treatment gave significantly worse results (p = .046). 
Fifty-seven (7.3%) patients reported unchanged limb function and 32 (4.1%) patients reported deterioration. 
Within 30 days two patients died and one patient underwent amputation. 
Within 1 year 10 patients underwent 11 amputations: five (1.7%) in the open surgery group, three (0.6%) in the endovascular treatment group, and two (7.5%) in the hybrid treatment group; one underwent bilateral amputation (p = .07). 
Twenty-two patients died: 10 (3.4%) in the open surgery group, 12 (2.7%) in the endovascular treatment group and none in the hybrid treatment group (p = .465).


My comments:

I do quote my patients a 2% risk of complication following endovascular intervention for IC, and 1% serious complication (amputaion, death, stroke, etc.). This is based on my audit of the Unit results (unofficial). This article from Sweden does reflect almost similiar results; but with death rate of 2-4% which is high. 
Would I consider/recommend intervention for IC: well, I do present those figures, discuss in MDT, excludes other pathologies, and give the patient time to think of their quality of life. If all fits, then yes I do offer intervention (this is standard practice in our unit), and usually the patient reaches the rest pain level before I do anything; therefore the risk of them losing their leg is 46% in 6 months (according to TASC II). 



when no leg veins are available, should you use the arm veins, or a PTFE?

Arm Vein as an Alternative Autogenous Conduit for Infragenicular Bypass in the Treatment of Critical Limb Ischaemia: A 15 Year Experience. EJVES June 2014

what do we know?
The results for bypass surgery using leg vein vs PTFE are listed in the TASC II guidelines:

What this article tells us:
The authors claim that: The favourable long term results of secondary patency and limb salvage rates encourage the use of arm veins as alternative conduits for infragenicular bypass surgery.

the results are as follows:

The current research shows the following results:

and this is the abstract:

Methods

This was a retrospective study. Between 1991 and 2005. 120 infragenicular bypasses using arm vein conduits (AVCs) were performed in 120 patients. CLI was the main indication (87.5%) for the procedures. The indications for using arm veins were inadequacy or absence of the ipsilateral greater saphenous vein (GSV). Survival, limb salvage, and patency rates were calculated using the Kaplan–Meier method.

Results

There was a predominance of male gender (65%), and the group mean age was 68.1 ± 8.3 years. The mean follow-up period was 29.6 ± 26.3 months. The operative mortality (30 days) rate was 7.5%. The main alternative conduit was non-spliced cephalic vein (37.5%). Composite grafts included GSV + AVC (45.2%), AVC + AVC (43.3%) and small saphenous vein + AVC (11.5%). The 5-year primary and secondary patency (SP) rates were 45.2 ± 5.6% and 56.5 ± 5.0%, respectively. The 5-year SP rate was greatest when using non-spliced cephalic vein (65.8 ± 7.6%), but there was no difference in cumulative patency between spliced and non-spliced veins (49.5 ± 8.0% vs. 61.2 ± 6.4%; p = 0.501). The 5-year limb salvage and survival rates were 70.6 ± 5.9% and 59.6 ± 5.8%, respectively.
my comments:
There is some 10-15% improvement in 5 year patency rate. Out of 10 patients, 4-5 will keep the PTFE graft in 5 years, vs 5-6 in arm veins. If arm vein harvesting is going to be a long operation, then a PTFE with a cuff is probably more suitable. If, however, there is enough staff, and there is a higher risk of infection, then arm veins are likely to be a better alternative. 

Is EVAR really better than Open repair in ruptured aneurysms?

Reflections on:

Endovascular Aneurysm Repair Versus Open Repair for Patients with a Ruptured Abdominal Aortic Aneurysm: A Systematic Review and Meta-analysis of Short-term Survival

Comments:

Two very interesting points should always be remembered: 
  1. Despite the fact that many observational reports showing significant reduction in 30-day- mortality rate, this systematic review has shown that the improvement does not exceed 10%. It is possible that the trials that managed eventually to recruit patients in such unstable condition has, be default, underwent selection bias toward people with better outcome anyway. 
  2. The physiologic medical logic support the idea that approaching the bleeding (ruptured AAA)via mini invasive surgery would be less harmful and less shocking to doing that with a wider laparotomy incision. The long-term results, however, is not only dependent on the access but also on the overall organ dysfunction during the period from rupture to bleeding cessation. See the comments by Lindholt er al.