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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3742_Библиотеки_им_академика_М_И_Перельмана
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320 Section 15: Dialysis Access
and after insertion revealed a 7% incidence of stenosis/occlusion centrally, especially in those
patients with a longer catheter dwell time. Sources of peripheral venous stenosis include NIH
in the outflow anastomosis, cephalic vein stenosis, incompetent valves, or feeding branches.
Symptoms of venous hypertension include fullness in the chest, swelling of the upper extremity,
and collateral veins seen in the chest wall.
Correct Answer D 17%–26%
Reference
Schwab, S. J., Quarles, L. D., Middleton, J. P., et al. (1988). Hemodialysis-associated subclavian vein
stenosis. Kidney Int, 33(6), 1156–1159. PMID: 2969991
28. RATIONALE
Significant stenosis at the venous anastomosis off the hemodialysis graft responds favorably to
standard balloon angioplasty. Primary patency within the first year after angioplasty is greater
than 50% while primary assisted patency is 80%–90%. If the suboptimal result is obtained with
a standard balloon angioplasty, high-pressure balloon or a cutting balloon angioplasty should
be considered as a second-line method of relieving the stenosis. Covered stent and bare-metal
stents are reserved for the management of complications and for central outflow stenosis. PTA is
the treatment of choice for stenosis caused by an obstruction of the fistulas. Repeated PTA may
be required for better long-term patency.
Correct Answer C Cutting balloon or high-pressure balloon angioplasty
Reference
Bountouris, I., Kritikou, G., Degermetzoglou, N., & Avgerinos, K. I. (2018). A review of percutane-
ous transluminal angioplasty in hemodialysis fistula. Int J Vasc Med, 2018, 1420136. PMID:
29785307
29. RATIONALE
(a) Venography demonstrates brachiocephalic (central) vein occlusion-Defibbrilator wires in the right IJ vein. (b) Post
Angioplast y and stenting across the brachiocephalic vein with reconst itution of blood f low.
Section 15: Dialysis Access 321
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Angioplasty for CVS may not be as effective in vessels with increased elasticity and recoil.
Angioplasty has even been shown to accelerate restenosis, with recurrent lesions showing a
more aggressive neointimal hyperplasia. PTA is the first-line approach as recommended by
KDOQI, with stenting reserved for angioplasty failure. However, an excellent early result but a
poor long-term patency of 50% at 6 months and 25% at 12 months has been reported with angioplasty alone. Stent grafts have shown better outcomes over bare-metal stents with improved primary and assisted patency rates. A covered stent may jail important collaterals of a central vein
leading complications for the future. In the setting of wires from the pacemaker/defibrillator, it
may be prudent to place a contralateral access for hemodialysis at the time of the index permanent arteriovenous access procedure. Open surgical management is considered a last remaining option for recurrence of failed endovascular management and includes internal jugular vein
transposition, axillo-jugular bypass, axillo-axillary crossover bypass, and axillo-atrial bypass.
Hybrid alternatives such as the Hemoaccess Reliable Outflow (HeRO) vascular access device
(Hemosphere, Inc., Minneapolis, MN) should be considered.
Correct Answer
D Covered stent
Reference
Agarwal, A. K. (2013). Central vein stenosis. Am J Kidney Dis, 61(6), 1001–1015. PMID: 23291234
30. RATIONALE
A review of a vascular quality initiative database of 3608 patients compared tapered with nontapered grafts. Tapered grafts had similar rates of ischemic steal at 3 months (4.1% vs. 4.6%) and on
multivariate analysis did not affect primary patency or reintervention rates of both open as well as
endovascular interventions. Therefore, tapered arteriovenous grafts for hemodialysis do not provide any additional advantage as compared to non-tapered grafts for hemodialysis access.
Correct Answer
C Similar primary patency
Reference
Roberts, L., Farber, A., Jones, D. W., et al. (2019). Tapered arteriovenous grafts do not provide signif-
icant advantage over nontapered grafts in upper extremity dialysis access. J Vasc Surg, 69(5),
1552–1558. PMID: 30583896
31. RATIONALE
Several factors contribute to the increased risk of bleeding in a patient on hemodialysis. A common etiology is anemia of chronic disease secondary to end-stage renal disease. As hematocrit
declines, there is reduced clearance of nitric oxide causing platelet inhibition and vasodilation,
and ultimately coagulopathy. Maintenance of hematocrit greater than 30% is the key, with an
inverse relationship between packed red cells and bleeding times. Uremia-induced platelet
dysfunction with ineffective adhesion to sub-endothelium from reduced expression of Gp1b
receptors and a reduced affinity for Von Willebrand factor (vWF) is associated with increased
risk of bleeding in a patient on hemodialysis. Treatment with desmopressin immediately acts
on endothelial vasopressin receptors, and CAMP-mediated signaling decreases bleeding time.
Maximal effect is seen at 1 hour lasting 4–6 hours. Infusion of other blood products to replenish
clotting factors may also be necessary.
Correct Answer D Desmopressin
322 Section 15: Dialysis Access
Reference
Kim, J. H., Baek, C. H., Min, J. Y., et al. (2015). Desmopressin improves platelet function in uremic
patients taking antiplatelet agents who require emergent invasive procedures. Ann Hematol,
94(9), 1457–1461. PMID: 25933676
32. RATIONALE
Most ESRD patients do not have kidney failure in isolation, with associated comorbidities
requiring antiplatelet or anticoagulant therapy being quite common such as history of deep
venous thrombosis, atrial fibrillation, and coronary artery disease, and the use of medications
increases bleeding risk in an already predisposed population towards coagulopathy. Physical
trauma of large-size needles during hemodialysis causes a continuous risk of bleeding. Pulsatile
bleeding with or without rapidly expanding hematoma should be temporarily controlled with
constant, direct pressure at the bleeding site for 30–40 minutes or until bleeding resolves.
Tourniquet application is rarely feasible, as most AV fistulas/AV grafts are placed in the upper
arm. If bleeding persists despite pressure, a suture may be placed through the skin and subcutaneous tissue but not through the underlying fistula/graft using proximal and distal manual
pressure to visualize the area of bleeding. Persistent pulsatile bleeding is concerning for venous
outflow stenosis, graft infection, and pseudoaneurysm. The patient will likely require a shuntogram. If there is skin comprise, including thinning/ulceration, with exposed access, an interposition graft tunneled in healthy tissue planes and sutured to a well-incorporated segment of a
previously placed graft near the arterial and the venous end anastomosis is recommended. Skin
breakdown over the graft needs emergent operation.
Correct Answer D Direct pressure for 30–40 minutes; if bleeding persists, place a suture over
the bleeding site and administer desmopressin, then evaluate the shunt by shuntogram followed by the appropriate management strategy
Reference
Inui, T., Boulom, V., Ba ndyk, D., et al. (2017). Dialysis access hemorrhage: access rescue from a surgica l
emergency. Ann Vasc Surg, 42, 45–49. PMID: 28341509
33. RATIONALE
Development of high-output heart failure is an underappreciated complication of permanent
dialysis access in patients with a proximal access and with a history of compensated heart
failure. Flow in a well-functioning access fistula is approximately 700–1500 mL/min. This may
result in left ventricular hypertrophy, reduced ejection fraction, and heart failure. Symptoms
include tachycardia, elevated pulse pressure, and jugular venous distention. On examination
the fistula appears large with rapid flow and aneurysmal growth, often referred to as a “mega
fistula.” Characteristic findings include pulmonary hypertension with normal pulmonary
vascular resistance and high cardiac output with low-normal systemic vascular resistance. In
patients with high cardiac output heart failure, intraoperative access flow monitoring demonstrates flow >2000 mL/min. Treatment involves reduction of flow as described in the rationale
for management of dialysis-associated steal syndrome (DASS).
Correct Answer D >2000 mL/min
Reference
Stern, A. B., & Klemmer, P. J. (2011). High-output heart failure secondary to arteriovenous fistula.
Hemodial Int, 15(1), 104–107. PMID: 21223485
Section 15: Dialysis Access 323
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34. RATIONALE
An arterio-arterial graft for hemodialysis is rarely indicated. The main indications are that all
large four deep veins (femoral and internal jugular vein) are occluded or are not suitable due to
septic complications; the patient in heart failure is refractory to therapy so that standard arterial venous access will have a negative effect on heart failure. To guarantee a sufficient flow for
effective dialysis access, always insert a loop graft in the course of an artery. A large size artery
with high f low is selected. The physiological advantage of arterio-arterial interposition grafts
includes their lack of effect on cardiac output or peripheral perfusion. The flow rate in these
grafts is typically around 150–250 cc/minute, which is much lower than the standard AV fistula
or graft; the time required for dialysis sessions is longer (5–6 hours). Large surface area dialyzers increase the efficiency of hemodialysis. Primary patency rates range from 67% to 94.5% at 6
months to 54% to 61% at 36 months with secondary patency rates from 83%–93% at 6 months to
72%–87% at 36 months.
Correct Answer D No change in cardiac output or peripheral perfusion with preference for
axillo-axillary loop grafts
Reference
Grima, M. J., Vriens, B., Holt, P. J., & Chemla, E. (2018). An arterioarterial prosthetic graft as an alter-
native option for haemodialysis access: a systematic review. J Vasc Access, 19(1), 45–51. PMID:
2914 8001
MCQs 1–9
SECTION 16: AMPUTATIONS
Q1. The most common indication for below
the knee amputation is:
A. Trauma
B. Failed arterial reconstruction for chronic
limb ischemia
C. Sarcoma involving lower leg
D. Critical limb ischemia in patients with diabe-
tes mellitus presenting as infected gangrene
Q2. In patients undergoing transmetatar-
sal amputation (TMA) for diabetic foot
ulceration, the risk of reulceration during
a follow-up time of 4 years is:
A. 15%–20%
B. 21%–30%
C. 31%–40%
D. 41% or higher
Q3. Contraindications to transmetatarsal
amputation (TMA) include all of the following except:
A. Forefoot infection, cellulitis
B. Dependent rubor involving the dorsal
forefoot proximal to the metatarsal phalangeal crease
C. Gangrenous changes in the plantar skin
extending proximal to the metatarsal
phalangeal crease
D. Patients above age 75
Q4. The conversion rate of below the knee
amputation to above the knee amputation
is approximately:
A. <5%
B. 6%–9%
C. 10%–15%
D. 16%–20%
Q5. The most common complication following
below the knee and above the knee amputations are:
A. Cardiac
B. Wound infection
C. Pneumonia
D. Hematoma
Q6. The following statement best reflects the
energy expenditure in patients with lower
extremity amputation:
A. An estimated 50% more energy is
expended to walk on an AKA prosthesis
compared to 20% on a BKA prosthesis
B. An estimated 60% more energy is
expended to walk on an AKA prosthesis
compared to 30% on a BKA prosthesis.
C. An estimated 70% more energy is
expended to walk on an AKA prosthesis
compared to 40% on a BKA prosthesis
Q7. All are potential complications of above
the knee amputation except:
A. Hematoma
B. Wound complications and stump
ischemia
C. Deep venous thrombosis
D. Arteriovenous fistula involving the
femoral artery and vein
Q8. Energy requirements with use of a pros-
thesis following hip disarticulation is:
A. 50% of normal ambulation
B. 100% of normal ambulation
C. 150% of normal ambulation
D. 200% of normal ambulation
Q9. The incidence of wound complications
following hip disarticulation is:
A. Less than 10%
B. 10%–15%
C. 16%–20%
D. 20%–50%
DOI: 10.1201/9781003389897-16
Section 16: Amputations 325
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RATIONALE 1–9
1. RATIONALE
A large proportion of amputations (82%) are performed for critical limb ischemia in patients
with diabetes mellitus presenting as infected gangrene despite prior attempts at repeated arterial reconstructions for limb salvage. Some patients with diabetes mellitus with chronic ulcers
in the feet present to the ER with gas gangrene and require emergent guillotine amputation
above the ankle to be followed by definitive amputation after source control, usually in 5–7 days
after guillotine amputation. Traumatic amputations following motor vehicle accident, combat, or terrorist attack are also common causes of below the knee amputation. Below the knee
amputation is the most common of all traumatic amputations with motor vehicle accidents. In
cases of severe infection, acute cellulitis needs to be controlled prior to amputation. The level of
amputation should be decided after assessing the type of pathology, potential for rehabilitation,
and presence of adequate perfusion. Clinical condition of the skin below the knee is an important determinate in the healing of the BK stump.
Correct Answer D Critical limb ischemia in patients with diabetes mellitus presenting as
infected gangrene
Reference
McIntyre, K. E. (2014). Below knee amputation. In J. C. Stanley, F. Veith, & T. W. Wakefield (Eds.),
Current therapy in vascular and endovascular surgery (pp. 647–648). Elsevier Health Sciences.
2. RATIONALE
Among 83 transmetatarsal amputations for diabetic foot ulcers over a 4-year period, reulceration occurred in 44% of patients with transmetatarsal amputation at a mean follow-up of
15 months after surgical healing. Successful transmetatarsal amputation is defined as one
which had clinical healing 1 year after surgery. Mean follow-up in the forementioned study
was 4 years and mean time to surgical healing was 109.8 days. Patients with reulceration were
younger, with a significantly higher preprocedure Hb1Ac.
Correct Answer D 41% or higher
Reference
Tokarski, A. R., Barton, E. C., Wagner, J. T., et al. (2022). Are transmetatarsal amputations a durable
limb salvage option? A single-institution descriptive analysis. J Foot Ankle Surg, 61(3), 537–541.
PMID: 34794876
3. RATIONALE
TMA is indicated for trauma, tissue loss, infection, and gangrene limited to the toes. TMA requires
shoe modification and inserts with forefoot space replacement. Amputation may be done for
gangrene extending a short distance on the dorsal skin past the metatarsal phalangeal crease,
provided plantar skin is healthy and arterial inf low is adequate. In patients with arterial occlusion
and dependent rubor, endovascular or open surgical reconstruction should be considered prior
to transmetatarsal amputation. Previous revascularization attempts, ABI equal to or less than 0.4,
insulin-dependent diabetes mellitus, low albumin level (less than 3.0 g/dL), and high C-reactive
protein are the important factors associated with poor transmetatarsal amputation outcomes.
326 Section 16: Amputations
Well-padded dressing with short-leg plaster cast will control edema and prevent stump trauma
immediately after TMA. Early ambulation after TMA should be avoided. A rigid dressing is used
until the transmetatarsal flap is well healed, which usually occurs 3–4 weeks following surger y.
Transmetatarsal amputation is not contraindicated in patients above 75 years of age.
Correct Answer D Patients above age 75
Reference
Aljarrah, Q., Allouh, M. Z., Husein, A., et al. (2022). Transmetatarsal amputations in patients with dia-
betes mellitus: a contemporary analysis from an academic tertiary referral centre in a developing community. PLoS ONE, 17(11), e0277117. PMID: 36327256
4. RATIONALE
The below the knee amputation site may not heal and may require further debridement, skin grafts,
and intensive wound care. In spite of all the available treatment modalities, approx imately 9.4%–12%
with below the knee amputation need to be converted to above the knee amputation. There is no
ideal test available to predict satisfactory healing of a below the knee stump. Doppler arterial evaluation, presence of popliteal pulse, transcutaneous oxygen measurements, and catheter-based arteriography are not completely reliable in predicting healing of a below the knee amputation. Clinical
examination with satisfactory condition of the skin at the site of amputation are as important as any
available test to determine the healing of a below the knee amputation site.
Correct Answer C 10%–15%
Reference
Aulivola, B., Hile, C. N., Hamdan, A. D., et al. (2004). Major lower extremity amputation: outcome of a
modern series. Arch Surg, 139(4), 395–399; discussion 399. PMID: 15078707
5. RATIONALE
From a study of 959 patients with lower extremity amputations (704 below the knee and
255 above the knee), the overall 30-day mortality was 16.5% for above the knee amputations
and 5.7% for below the knee amputations (P ≤0.001). Complications include cardiac (10.2%),
wound infection (5.5%), and pneumonia (4.5%). Overall survival was 69.7% at 1 year and 34.7%
at 5 years. Survival was significantly worse for above the knee amputations (50.6% at 1 year and
22.5% at 5 years) than below the knee amputation (74.5% at 1 year and 37.8% at 5 years, p <0.001).
Survival in patients with diabetes mellitus and end-stage renal disease was significantly worse
than those undergoing lower extremity amputations without diabetes mellitus or ESRD.
Correct Answer A Cardiac
Reference
Aulivola, B., Hile, C. N., Hamdan, A. D., et al. (2004). Major lower extremity amputation: outcome of a
modern series. Arch Surg, 139(4), 395–399; discussion 399. PMID: 15078707
6. RATIONALE
The ability to ambulate for patients who have undergone major amputations of the lower
extremity is largely determined by the level of amputation. The energy expenditure in the
Section 16: Amputations 327
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case of transmetatarsal amputation is increased by 16%–33% at a comfortable walking speed.
Transfemoral amputations require 65%–70% more energy, and in patients with above the knee
amputation, an estimated 70% more energy is expended with use of a prosthesis as compared to
40% with a below the knee amputation prosthesis.
Correct Answer C An estimated 70% more energy is expended to walk on an AKA prosthesis
compared to 40% on a BKA prosthesis
Reference
Chin, T., Sawamura, S., Shiba, R., et al. (2005). Energy expenditure during walking in amputees
after disarticulation of the hip. A microprocessor-controlled swing-phase control knee versus
a mechanical-controlled stance-phase control knee. J Bone Joint Surg Br, 87(1), 117–119. PMID:
15686251
7. RATIONALE
Deep venous thrombosis has been reported in up to 50% of patients following major lower
extremity amputations and may result in mortality in a large proportion of such patients.
Venous thromboembolic prophylaxis is essential in patients undergoing major amputation.
Incidence of wound complication is 40%, most often secondary to ischemia and wound infection. Wound infections are more common when amputation is performed for infectious indications and in patients with diabetes mellitus, malnutrition, malignancy, wound hematoma, and
prior prosthetic graft arterial reconstruction. Excisional debridement, systemic antibiotics, and
nutritional optimization are essential. Vacuum-assisted dressings are very useful. Stump ischemia manifests as persistent pain with pallor and coolness of the stump with blister formation.
Mortality following above the knee amputation ranges from 11% to 18%. The survival rate after
1 year is approximately 50%, and less than 10% of elderly patients can walk using an above the
knee prosthesis.
Correct Answer D Arteriovenous fistula involving the femoral artery and vein
Reference
Nehler, M. R., Coll, J. R., Hiatt, W. R., et al. (2003). Functional outcome in a contemporary series of
major lower extremity amputations. J Vasc Surg, 38(1), 7–14. PMID: 12844082
8. RATIONALE
Hip disarticulation is most often performed for treatment of high-grade diaphyseal tumors
distal to the lesser trochanter, occasionally after massive trauma, severe infections, massive
decubitus ulcers, severe arterial insufficiency, and congenital limb anomalies. Few patients are
able to utilize a prosthesis, as energy requirements to use a prosthesis following disarticulation
have been estimated to be 200% of normal ambulation. Mortality rates up to 44% have been
reported following disarticulation of the hip.
Correct Answer D 200% of normal ambulation
Reference
Sugarbaker, P. H., & Chretien, P. B. (1981). A surgical technique for hip disarticulation. Surgery, 90(3),
546–553. PMID: 7268632
328 Section 16: Amputations
9. RATIONALE
A review of 53 hip disarticulations performed for atherosclerotic arterial occlusive disease in 10,
infection in 12, infection and ischemia in 14, and tumors 17 demonstrated an overall mortality of 20.8%, with 50% mortality in patients who underwent hip disarticulation due to arterial
occlusive disease. No patient was able to use a prosthesis, but most were independent in wheelchairs. The incidence of wound complications following hip disarticulation is 20%–50%. In
patients with gangrene of the extremity with prior failed revascularization attempts, hip disarticulation should not be delayed in those for whom above the knee or subtrochanteric amputation is not feasible. Prior above the knee amputation and urgent operation were associated with
increased risk of wound complications following hip disarticulation. Both limb ischemia and
wound infection substantially increase the morbidity and mortality of disarticulation of the hip.
Correct Answer D 200% of normal ambulation
Reference
Endean, E. D., Schwarcz, T. H., Barker, D. E., et al. (1991). Hip disarticulation: factors affecting out-
come. J Vasc Surg, 14 (3), 398–404. PMID: 1880849
SECTION 17: ENDOVASCULAR
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RETRIEVAL OF FOREIGN BODIES
MCQs 1–4
Q1. The incidence of fragmentation or embo-
lization of a central venous catheter is
approximately:
A. 1%
B. 2%
C. 3%
D. 4%
Q2. The most optimal method to retrieve an
intravascular foreign body is:
A. Open surgical removal
B. Endovascular removal with loop snare
C. Endovascular using retrieval forceps and
using internal jugular vein access
D. Endovascular with retrieval forceps and
using femoral vein access
Q3. A fragment of a mediport catheter broke
and lodged in the right pulmonary artery
branch. The best option for access in
removing the foreign body is via:
A. Right subclavian vein
B. Right femoral vein
C. Right internal jugular vein
D. Open operative removal
Q4. Endovascular retrieval forceps are best
used for:
A. Cutting the struts of the IVC filter
B. Removing an IVB with a free end
C. Removing a spherical or an ovoid object
(bullet)
D. Removing an IFB without a free end
DOI: 10.1201/9781003389897-17
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