Vascular OnlineFirst, published on March 11, 2015 as doi:10.1177/1708538115576428
Original Article Vascular 0(0) 1–6 ! The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1708538115576428 vas.sagepub.com
Palmar arch anatomy: Ajmer Working Group classification Rajendra Gokhroo, Devendra Bisht, Sajal Gupta, Kamal Kishor and Bhanwar Ranwa
Abstract Introduction: Forearm arteries are frequently used as workhorse site for cardiac catheterization, bypass grafting and haemodialysis access. There is paucity of data on palmar circulation in live human being and only cadaveric data are available till date. We, therefore, made an attempt to look at the various patterns of sufficient or insufficient palmar arch circulation and various anomalies of forearm arteries, to discuss their clinical implications. Methods and results: We obtained the forearm and hand arteriograms of patients (n ¼ 302) through radial (n ¼ 200) and ulnar routes (n ¼ 102). Modified Allen’s test was normal in all of our patients. On the basis of predetermined parameters angiograms were analysed and findings were divided into three groups. These three groups were further classified as type A, type B, type C superficial palmar arch. Conclusion: We concluded that type A superficial palmar arch is most suitable for providing adequate collateral circulation in case of harvesting of forearm vessel, whereas type C superficial palmar arch appears to be highly susceptible for digital ischemia in case of radial or ulnar artery occlusion. Modified Allen’s test alone is not justifiable for documenting good collateral circulation and it should be supplemented by other tests to document good collateral circulation before proceeding to any radical procedure.
Keywords Palmar arch, cardiac catheterization, Allen test
Introduction The human hand is perfused by radial and ulnar arteries, which anastomose across the hand in the form of a superficial palmar arch (SPA) and a deep palmar arch (DPA). Therefore, SPA is an arterial arcade, formed by the anastomosis between the superficial branch of the ulnar artery and completed laterally by one of the branch of radial artery i.e. superficial palmar branch, arteria radialis indicis or arteria princeps pollicis. Of the two plamar arches, the SPA is the most important route to provide blood supply to the digital arteries. However, the SPA its contributing arteries are highly variable.1,2 The forearm arteries (radial and ulnar) are frequently used as a workhorse site for cardiac catheterization. Radial artery can be harvested to be used as coronary artery bypass graft without ischemic complications to the hand. Furthermore, the radial artery is a favourable access for haemodialysis access if sufficient ulnar collateral flow is present.
A variety of techniques3–8 to assess the capability of the ulnar artery to provide adequate perfusion to the hand in the event of radial artery removal or thrombosis have been proposed. These techniques have had sparse clinical validation. Allen’s test is the most commonly used bedside test to document adequacy of palmar circulation, but this test is subjective and unreliable, with many false-positive and false-negative results.9,10 Considering the reliability of modified Allen’s test (MAT) Pola et al.,6 Serrichio et al.8 and Zimmerman et al.11 showed that all the follow-up patients who Post Graduate Department of Cardiology, JLN Medical College & Associated Group of Hospitals, Ajmer, Rajasthan, India Corresponding author: Devendra Bisht, Post Graduate Department of Cardiology, JLN Medical College & Associated Group of Hospitals, Ajmer – 305 001, Rajasthan, India. Email: [email protected]
Downloaded from vas.sagepub.com at University of Manitoba Libraries on June 11, 2015
2
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underwent harvesting of the radial artery after a negative MAT did not have signs of hand ischemia. But Starnes et al.7 showed that MAT may unnecessarily exclude some patients from radial artery harvesting and radial access for haemodialysis (false-positive results) and may also place a number of patients at risk for hand ischemia (false negative). Kaminski and barnes10 reported a 73% false-positive rate of the MAT. Therefore, even MAT is not 100% sensitive or 100% specific for detecting adequate collateral flow to the digital arteries. To minimize the risk of hand ischemia, many surgeons advocate evaluation of the forearm and palmar circulation prior to radial artery harvesting. This evaluation has two major objectives: (1) to eliminate the possibility of post harvest ischemia of the hand and (2) to ensure that the radial artery is free of atherosclerosis and of appropriate size. Although upper extremity arterial atherosclerosis is uncommon, individuals with coronary artery disease are at higher risk. The purpose of the present study was (1) to assess the potential availability of forearm artery as a bypass conduit or haemodialysis access, (2) to assess the potential risk of hand ischemia during radial or ulnar arterial cannulation and (3) to assess the reliability of Allen’s test for documenting adequacy of palmar circulation.
Methods This was a prospective, open label, single center, observational study. Procedures were performed by single operator and analysed by five cardiologists. We obtained the forearm and hand arteriograms of patients (n ¼ 302) undergoing routine coronary angiography through radial and ulnar route. We, also, made an attempt to look at the various pattern of sufficient or insufficient palmar arch circulation and various anomalies of forearm arteries. We also tried to classify palmar arch circulation angiographically depending upon predetermined parameters. This classification is intended to guide the cardiologists, nephrologists and vascular surgeons for possible risk of hand ischemia in patients undergoing transradial/ transulnar cardiac catheterization, haemodialysis or radial artery harvesting for coronary artery bypass grafting, respectively. The Barbeau method was used to document the adequacy of palmar arch flow. Forearm access for the procedure was deemed contraindicated if the D type of response to the procedure was documented.12,13 The other pre-procedural exclusion criteria were absent clinical radial or ulnar artery pulsations; cardiogenic shock; patients on chronic haemodialysis; severe
dermomyoskeletal forearm deformities; history of CABG and bilateral use of either the internal mammary or radial artery. All patients had given written informed consent and patients allergic to radiographic contrast agent were excluded. Arterial cannulation was performed with judkin’s technique. With the help of 5 French TIG catheter, contrast was injected at the bifurcation of brachial artery and cine images were recorded for subsequent analysis. Only a nonionic contrast agent with low osmolarity was used. SPA and ulnar arterial angiogram were analysed through arterial cannulation of radial artery as superficial arch is formed predominantly through ulnar artery. Similarly deep palmar arch and radial artery was analysed through arterial cannulation of ulnar artery as deep arch is formed predominantly through radial artery. Both arteries were not cannulated in the same patient. After detailed analysis we tried to classify these observations on the basis of pre-determined parameters and a working classification was brought out (Table 4).
Terminology and arteriogram analysis We used the same terminology as used in previous studies. Five experienced cardiologists analysed the arteriograms under the following predetermined parameters— 1. Completeness of palmar arch 2. Arterial dominance of palmar arch 3. Average diameter of the forearm arteries (radial and ulnar) proximal to the wrist joint 4. Atherosclerotic changes in forearm and palmar arteries 5. Distal slow flow in palmar circulation 6. Number of digits supplied by ulnar artery 7. Average size of palmar arteries 8. Average size of digital arteries Completeness of the palmar arch was considered when the major artery forming the arch (e.g. ulnar artery for SPA and radial artery for DPA) was completed from contralateral side by one of the braches of another artery without any angiographically visible interruption of the arch. The major artery, supplying more than three digits via digital arteries, was considered as dominant whereas equal distribution of either artery (radial and ulnar) to digital supply was considered as co-dominant supply. Average arterial diameters were calculated quantitatively by software provided by the machine and other findings of the arteriograms were noted from cine images.
Downloaded from vas.sagepub.com at University of Manitoba Libraries on June 11, 2015
Gokhroo et al.
3
Observations On the basis of predetermined parameters angiograms obtained from 302 patients (n ¼ 302) were analysed (Table 1–3) (Figure 1) and findings were divided into three groups. These three groups were further classified as type A, type B and type C palmar arches (Table 4).
None of our patient suffered any major complication, only minor complications viz access site bleed in five patients, acute loss of ulnar pulse in four patients and absence of ulnar pulse at discharge were noted in three patients.
Discussion Table 1. Baseline characteristics of the study patients (n ¼ 302). Patient characteristics
Total (n ¼ 302)
Age distribution mean SD, (yrs) Male sex (%)
58.59 11.3 189 (62.6)
Presenting diagnosis (%) ACS-STEMI ACS-NSTEMI/UA Chronic stable angina Miscellaneous
144 90 49 19
(47.6) (29.8) (16.2) (6.4)
Co-morbidities Hypertension (%) Diabetes (%) Smokers (%) Dyslipidemia (%) Chronic kidney disease (CKD) (%) Allen’s test normal (%) Modified allen’s test normal (%)
154 87 135 154 41 299 302
(50.9) (28.8) (44.7) (50.9) (13.6) (99) (100)
Table 2. Detailed analysis of superficial palmar arch (SPA) and deep palmar arch (DPA) after selective angiograms from radial and ulnar artery access respectively. Parameters
SPA (n ¼ 200)
DPA (n ¼ 102)
Completeness of the SPA or DPA 1. Complete arch 2. Incomplete arch
149 51
56 46
Dominance 1. Radial artery 2. Ulnar artery 3. Co-dominance
27 145 28
47 44 11
Atherosclerotic changes 1. No atherosclerotic changes 2. Mild atherosclerotic changes 3. Diffuse atherosclerotic changes Slow flow distally 1. Distal slow flow present 2. Distal slow flow absent Average size of palmar arteries Average size of digital arteries
127 48 25
Till date, most of the studies incorporating palmar arch were done on cadavers. These studies provide us the various anatomical variations of forearm circulation, but not the physiological significance of this important circulation. We all know that intraluminal diameter is an indicator of blood flow and is therefore relevant in ensuring good reperfusion of local structures during intervention, but cadaveric studies provide only the external diameter and not the intraluminal diameter. One of the first reports that presented a complex anatomical classification of the SPAs was the classic work of Coleman and Anson.14 Since then, many other classifications have been suggested by different authors (Karlsson and Niechajev,15 Al-Turk and Metcalf,16 Doscher et al.,17 Ruengsakulrach et al.18 and Gellman et al.19 Other studies have also shown that the vascular anatomy of the palmar arches is highly variable.20 The high degree of variability in palmar circulation makes it important to have a uniform segmental classification system for cannulating these vessels. Here we have attempted to include the different variations of palmar circulation and forearm arteries in the form of a working classification, of which the operator should be aware while performing interventions. Several anatomic variants may lead to hand ischemia with radial artery harvesting. These include an incomplete SPA, radial artery dominance of the SPA and absence or malformation of the ulnar artery.7,21
60 26 16
Table 3. Working classification of superficial palmar arch (SPA) depending on predetermined parameters into type A, type B and type C. No’s in bracket depicts the patients’ number having that finding. Parameters (n ¼ 200)
Type A
Type B
Type C
Dominance
Co-dominance (28)
Ulnar (145)
Radial (27)
Completeness
Yes (149)
No (51)
Diameter of both vessels (>2.5 mm)*
Yes (49)
No (151)
Only one vessel >2.5 mm*
No
Both vessels
Original Article Vascular 0(0) 1–6 ! The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1708538115576428 vas.sagepub.com
Palmar arch anatomy: Ajmer Working Group classification Rajendra Gokhroo, Devendra Bisht, Sajal Gupta, Kamal Kishor and Bhanwar Ranwa
Abstract Introduction: Forearm arteries are frequently used as workhorse site for cardiac catheterization, bypass grafting and haemodialysis access. There is paucity of data on palmar circulation in live human being and only cadaveric data are available till date. We, therefore, made an attempt to look at the various patterns of sufficient or insufficient palmar arch circulation and various anomalies of forearm arteries, to discuss their clinical implications. Methods and results: We obtained the forearm and hand arteriograms of patients (n ¼ 302) through radial (n ¼ 200) and ulnar routes (n ¼ 102). Modified Allen’s test was normal in all of our patients. On the basis of predetermined parameters angiograms were analysed and findings were divided into three groups. These three groups were further classified as type A, type B, type C superficial palmar arch. Conclusion: We concluded that type A superficial palmar arch is most suitable for providing adequate collateral circulation in case of harvesting of forearm vessel, whereas type C superficial palmar arch appears to be highly susceptible for digital ischemia in case of radial or ulnar artery occlusion. Modified Allen’s test alone is not justifiable for documenting good collateral circulation and it should be supplemented by other tests to document good collateral circulation before proceeding to any radical procedure.
Keywords Palmar arch, cardiac catheterization, Allen test
Introduction The human hand is perfused by radial and ulnar arteries, which anastomose across the hand in the form of a superficial palmar arch (SPA) and a deep palmar arch (DPA). Therefore, SPA is an arterial arcade, formed by the anastomosis between the superficial branch of the ulnar artery and completed laterally by one of the branch of radial artery i.e. superficial palmar branch, arteria radialis indicis or arteria princeps pollicis. Of the two plamar arches, the SPA is the most important route to provide blood supply to the digital arteries. However, the SPA its contributing arteries are highly variable.1,2 The forearm arteries (radial and ulnar) are frequently used as a workhorse site for cardiac catheterization. Radial artery can be harvested to be used as coronary artery bypass graft without ischemic complications to the hand. Furthermore, the radial artery is a favourable access for haemodialysis access if sufficient ulnar collateral flow is present.
A variety of techniques3–8 to assess the capability of the ulnar artery to provide adequate perfusion to the hand in the event of radial artery removal or thrombosis have been proposed. These techniques have had sparse clinical validation. Allen’s test is the most commonly used bedside test to document adequacy of palmar circulation, but this test is subjective and unreliable, with many false-positive and false-negative results.9,10 Considering the reliability of modified Allen’s test (MAT) Pola et al.,6 Serrichio et al.8 and Zimmerman et al.11 showed that all the follow-up patients who Post Graduate Department of Cardiology, JLN Medical College & Associated Group of Hospitals, Ajmer, Rajasthan, India Corresponding author: Devendra Bisht, Post Graduate Department of Cardiology, JLN Medical College & Associated Group of Hospitals, Ajmer – 305 001, Rajasthan, India. Email: [email protected]
Downloaded from vas.sagepub.com at University of Manitoba Libraries on June 11, 2015
2
Vascular 0(0)
underwent harvesting of the radial artery after a negative MAT did not have signs of hand ischemia. But Starnes et al.7 showed that MAT may unnecessarily exclude some patients from radial artery harvesting and radial access for haemodialysis (false-positive results) and may also place a number of patients at risk for hand ischemia (false negative). Kaminski and barnes10 reported a 73% false-positive rate of the MAT. Therefore, even MAT is not 100% sensitive or 100% specific for detecting adequate collateral flow to the digital arteries. To minimize the risk of hand ischemia, many surgeons advocate evaluation of the forearm and palmar circulation prior to radial artery harvesting. This evaluation has two major objectives: (1) to eliminate the possibility of post harvest ischemia of the hand and (2) to ensure that the radial artery is free of atherosclerosis and of appropriate size. Although upper extremity arterial atherosclerosis is uncommon, individuals with coronary artery disease are at higher risk. The purpose of the present study was (1) to assess the potential availability of forearm artery as a bypass conduit or haemodialysis access, (2) to assess the potential risk of hand ischemia during radial or ulnar arterial cannulation and (3) to assess the reliability of Allen’s test for documenting adequacy of palmar circulation.
Methods This was a prospective, open label, single center, observational study. Procedures were performed by single operator and analysed by five cardiologists. We obtained the forearm and hand arteriograms of patients (n ¼ 302) undergoing routine coronary angiography through radial and ulnar route. We, also, made an attempt to look at the various pattern of sufficient or insufficient palmar arch circulation and various anomalies of forearm arteries. We also tried to classify palmar arch circulation angiographically depending upon predetermined parameters. This classification is intended to guide the cardiologists, nephrologists and vascular surgeons for possible risk of hand ischemia in patients undergoing transradial/ transulnar cardiac catheterization, haemodialysis or radial artery harvesting for coronary artery bypass grafting, respectively. The Barbeau method was used to document the adequacy of palmar arch flow. Forearm access for the procedure was deemed contraindicated if the D type of response to the procedure was documented.12,13 The other pre-procedural exclusion criteria were absent clinical radial or ulnar artery pulsations; cardiogenic shock; patients on chronic haemodialysis; severe
dermomyoskeletal forearm deformities; history of CABG and bilateral use of either the internal mammary or radial artery. All patients had given written informed consent and patients allergic to radiographic contrast agent were excluded. Arterial cannulation was performed with judkin’s technique. With the help of 5 French TIG catheter, contrast was injected at the bifurcation of brachial artery and cine images were recorded for subsequent analysis. Only a nonionic contrast agent with low osmolarity was used. SPA and ulnar arterial angiogram were analysed through arterial cannulation of radial artery as superficial arch is formed predominantly through ulnar artery. Similarly deep palmar arch and radial artery was analysed through arterial cannulation of ulnar artery as deep arch is formed predominantly through radial artery. Both arteries were not cannulated in the same patient. After detailed analysis we tried to classify these observations on the basis of pre-determined parameters and a working classification was brought out (Table 4).
Terminology and arteriogram analysis We used the same terminology as used in previous studies. Five experienced cardiologists analysed the arteriograms under the following predetermined parameters— 1. Completeness of palmar arch 2. Arterial dominance of palmar arch 3. Average diameter of the forearm arteries (radial and ulnar) proximal to the wrist joint 4. Atherosclerotic changes in forearm and palmar arteries 5. Distal slow flow in palmar circulation 6. Number of digits supplied by ulnar artery 7. Average size of palmar arteries 8. Average size of digital arteries Completeness of the palmar arch was considered when the major artery forming the arch (e.g. ulnar artery for SPA and radial artery for DPA) was completed from contralateral side by one of the braches of another artery without any angiographically visible interruption of the arch. The major artery, supplying more than three digits via digital arteries, was considered as dominant whereas equal distribution of either artery (radial and ulnar) to digital supply was considered as co-dominant supply. Average arterial diameters were calculated quantitatively by software provided by the machine and other findings of the arteriograms were noted from cine images.
Downloaded from vas.sagepub.com at University of Manitoba Libraries on June 11, 2015
Gokhroo et al.
3
Observations On the basis of predetermined parameters angiograms obtained from 302 patients (n ¼ 302) were analysed (Table 1–3) (Figure 1) and findings were divided into three groups. These three groups were further classified as type A, type B and type C palmar arches (Table 4).
None of our patient suffered any major complication, only minor complications viz access site bleed in five patients, acute loss of ulnar pulse in four patients and absence of ulnar pulse at discharge were noted in three patients.
Discussion Table 1. Baseline characteristics of the study patients (n ¼ 302). Patient characteristics
Total (n ¼ 302)
Age distribution mean SD, (yrs) Male sex (%)
58.59 11.3 189 (62.6)
Presenting diagnosis (%) ACS-STEMI ACS-NSTEMI/UA Chronic stable angina Miscellaneous
144 90 49 19
(47.6) (29.8) (16.2) (6.4)
Co-morbidities Hypertension (%) Diabetes (%) Smokers (%) Dyslipidemia (%) Chronic kidney disease (CKD) (%) Allen’s test normal (%) Modified allen’s test normal (%)
154 87 135 154 41 299 302
(50.9) (28.8) (44.7) (50.9) (13.6) (99) (100)
Table 2. Detailed analysis of superficial palmar arch (SPA) and deep palmar arch (DPA) after selective angiograms from radial and ulnar artery access respectively. Parameters
SPA (n ¼ 200)
DPA (n ¼ 102)
Completeness of the SPA or DPA 1. Complete arch 2. Incomplete arch
149 51
56 46
Dominance 1. Radial artery 2. Ulnar artery 3. Co-dominance
27 145 28
47 44 11
Atherosclerotic changes 1. No atherosclerotic changes 2. Mild atherosclerotic changes 3. Diffuse atherosclerotic changes Slow flow distally 1. Distal slow flow present 2. Distal slow flow absent Average size of palmar arteries Average size of digital arteries
127 48 25
Till date, most of the studies incorporating palmar arch were done on cadavers. These studies provide us the various anatomical variations of forearm circulation, but not the physiological significance of this important circulation. We all know that intraluminal diameter is an indicator of blood flow and is therefore relevant in ensuring good reperfusion of local structures during intervention, but cadaveric studies provide only the external diameter and not the intraluminal diameter. One of the first reports that presented a complex anatomical classification of the SPAs was the classic work of Coleman and Anson.14 Since then, many other classifications have been suggested by different authors (Karlsson and Niechajev,15 Al-Turk and Metcalf,16 Doscher et al.,17 Ruengsakulrach et al.18 and Gellman et al.19 Other studies have also shown that the vascular anatomy of the palmar arches is highly variable.20 The high degree of variability in palmar circulation makes it important to have a uniform segmental classification system for cannulating these vessels. Here we have attempted to include the different variations of palmar circulation and forearm arteries in the form of a working classification, of which the operator should be aware while performing interventions. Several anatomic variants may lead to hand ischemia with radial artery harvesting. These include an incomplete SPA, radial artery dominance of the SPA and absence or malformation of the ulnar artery.7,21
60 26 16
Table 3. Working classification of superficial palmar arch (SPA) depending on predetermined parameters into type A, type B and type C. No’s in bracket depicts the patients’ number having that finding. Parameters (n ¼ 200)
Type A
Type B
Type C
Dominance
Co-dominance (28)
Ulnar (145)
Radial (27)
Completeness
Yes (149)
No (51)
Diameter of both vessels (>2.5 mm)*
Yes (49)
No (151)
Only one vessel >2.5 mm*
No
Both vessels
