Popliteal Entrapment Syndrome M. H. L. GIBSON, PH.D., J. G. MILLS, M.S., G. E. JOHNSON, M.D., A. R. DOWNS, M.D.*
A probable cause of popliteal artery entrapment is proposed. The medial head of the gastrocnemius muscle during its embryological development crosses the popliteal fossa from lateral to medial. It is proposed that the migrating medial head carries the popliteal artery and vein across the fossa and entraps them against the medial condyle of the femur. Dissection of 86 anatomical specimens revealed two cases of unilateral and one case of bilateral entrapment of both popliteal vessels. Two surgical cases of popliteal entrapment are presented. This entrapment syndrome is a remedial cause of claudication and when considered, it is readily diagnosed and surgical correction is effective. Because of distal embolisation and occlusions, early recognition and treatment is desirable. Forty-seven cases from the literature are reviewed as to the entrapment type and the age and sex of the patients. Submitted for publication June 18, 1976. Department of Surgery, Health Sciences Centre, 700 William Avenue, Winnipeg, Manitoba, Canada R3E OW3 *
From the Departments of Anatomy, University of Manitoba, Faculty of Medicine, Winnipeg, and Michigan State University, East Lansing, Michigan, U.S.A., and the Department of Surgery, University of Manitoba, Health Sciences Centre, Winnipeg, Canada
SINCE the first reported case by Stuart,32 over 95 years ago there has been an ever increasing interest and awareness of the entrapment syndrome of the popliteal artery. The entrapment of the popliteal artery is a rare cause of ischemia of the lower limb. However, to date there have been well over 50 reported cases of this syndrome in the literature. This syndrome typically involves either an aberrant path for the popliteal vessels or an aberrant attachment of the gastrocnemius or plantaris muscles over the normally popl
i tea profunda.
a.
FEMUR
medial inferior genicular a.
ADULT POPLITEAL A.
T I B IA
FIG. 1. A schematic medial view of the embryological development of the popliteal artery (modified from Senior, 1919).
poplitea superficialis a.]
posterior tibial recurrent a.
peroneal a.
anterior tibi recurrent a.
posterior tibial a.
anterior a.
=
popl iteus muscle
=
tibialis posterior muscle
= = =
341
degenerated portion of the poplitea profunda a.
342
GIBSON AND OTHERS
Ann. Stirg. * Mai-ch 1977
artery forming the lower segment (Fig. 1). Originally the major blood supply to the leg is via the poplitea profunda artery, passing between the anterior surface of the popliteus muscle and the posterior surface of the tibia (Fig. 1). However, by the 22 mm stage the superficialis poplitea artery is sufficiently well developed and begins to act as an additional blood supply to the leg. By the 24.5 mm stage the segment of the poplitea profunda artery passing anterior to the popliteus muscle has ceased to exist. Beginning at this stage of development the leg is supplied by the superficialis poplitea artery lying on the posterior surface of the popliteus muscle. Therefore, the main arterial channel through the popliteal region has been transferred from the anterior to the posterior surface of the popliteus muscle (Fig. 1).
FIGS. 2a and b. Case 1. F. N. (left) There is marked medial displaceof the popliteal artery at the level of the femoral condyle. (right) The flow contrast media is delayed in the portion of the popliteal artery which is displaced. ment
positioned vessels.24 In either case, the popliteal or accompanied by its vein are compressed against the condyle of the femur, producing intermittent claudication of the affected limb as the most common patient complaint. The purpose of this paper is to explain embryologically a possible cause of this entrapment, and its incidence in a population of dissected human specimens, and also to report on two clinical cases in which the presence of multiple distal occlusions emphasizes the importance of early diagnosis and artery either alone
treatment.
Embryology of the Popliteal Artery The formation of the adult human popliteal artery, according to Senior,30 results from the union of two embryonic vessels; the poplitea profunda artery forming the upper segment and the superficialis poplitea
Embryology of the gastrocnemius muscle At about the time the major arterial supply to the leg changes from the anterior to the posterior surface of the popliteus muscle, the development of the gastrocnemius muscle is well advanced.3'25 Earlier detection reveals that the anlage of the gastrocnemius is attached inferiorly to the developing calcaneus and by the 14 mm stage (5.5 wks) the medial and lateral heads of the muscle are distinct. At this time the two heads of the gastrocnemius are in the active process of migrating from their original lateral position in the developing leg, superiorly towards their adult attachments on the femur.3'25 By the 20 mm stage (7 wks) the lateral head of the gastrocnemius has formed a tendinous attachment to the lateral epicondyle of the femur. However, at this stage the medial head of the gastrocnemius has not yet attained its femoral attachment.3 It continues to migrate medially and superiorly, eventually attaching to the medial epicondyle of the femur, usually at a level more cranial than the attachment of the lateral head. Dissected specimens From among the specimens willed to the Departments of Anatomy at The University of Manitoba and Michigan State University a total of 86 human specimens were selected for dissection. Of these, 22 were female. In each specimen the popliteal region of both limbs was dissected to determine if the popliteal vessels took a normal course through the popliteal fossa or whether they were compressed by an aberrant muscle slip or tendon. In three specimens dissected, there were popliteal vessels taking a deviate course through the popliteal region. Two of these specimens, a 72-year-old male and a 85-year-old female, at the time of their death had a unilateral entrapment of the right popliteal vessels. The third
343
POPLITEAL ENTRAPMENT SYNDROME
Vol. 185 * No. 3
I
FIG. 3a. Case 1. F. N.
Operative photograph -the popliteal artery emerges from between the two portions of the origin of the medial head of the gastrocnemius (at the point of the scissors). Distal to this, the artery is moderately dilated.
specimen, a 66 year old male had a bilateral entrapment of both popliteal vessels. In all three cases the vessels were passing through the medial head of the gastrocnemius muscle. Histological sections of the entrapped vessels showed no occlusion of the lumen and essentially were normal. The records of the deceased were scrutinized and it was found that each had complained of mild intermittent claudication in the affected limb(s) for a number of years.
drome. At operation the popliteal artery at the level of the knee joint lay between two portions of the medial head of the gastrocnemius muscle and was compressed by the tendinous lateral portion. Just distal to the site of compression the artery was slightly dilated (Fig. 3).
I
Case Reports Case 1: F.N., a 43-year-old school inspector who was previously well, presented in May 1968 complaining of claudication in the right calf and numbness and tingling in his right foot on walking. He was a non-smoker and there was no history of cardiac or cerebral disease. On physical examination his blood pressure was 120/80, pulse was 72 and regular. The right popliteal pulse was graded three out of four. The dorsalis pedis and posterior tibial pulses were absent. The right leg below the knee was cooler than the left. All other peripheral pulses were normal. The systolic pressure at the right ankle was 85 mm Hg and at the left ankle 135 mm Hg when the right brachial blood pressure was 122/80 mm Hg. The serum cholesterol was 155 mg/100 ml and triglycerides were 149 mg/100 ml. A right femoral angiogram revealed normal femoral and iliac arteries. At the level of the femoral condyles the popliteal artery was displaced rather abruptly medially and returned to its normal position just below the level of the knee joint (Fig. 2a and b). The artery was narrowed at the site of the displacement with an irregular lumen. The anterior tibial artery was occluded. The diagnosis preoperatively was thrombosed popliteal aneurysm with distal propagation of the thrombus or popliteal entrapment syn-
"
,/
\
\\
/
l!
/./-
FIG. 3b. Line diagram of operative findings. (1) Medial tendinous origin of medial head of gastrocnemius. (2) Lateral muscular origin of medial head of the gastrocnemius. (3) Popliteal artery lying between the two origins of the medial head of the gastrocnemius.
GIBSON AND OTHERS
344
-,.e6J,:
dilated
The
graft
portion
in the normal
position
right
muscle. A
its normal
lying 10
There
Hg.
a
were
The left
position.
The
right
pressure
time
of the
asymptomatic.
followup
three
systolic
The
Pathological
examination
diameter
of
1.3
a
of cm.
pressure
right
the
resected
The
dilated
in
was
128/80
mm
days post-
first detected.
was
was
pressure
13
half years
pressure at the
Hg when the right brachial blood maximum
and
right
patent and
was
pedal pulses palpable until
no
The post-
the
was
systolic
ankle
placed
was
gastrocnemius
on
popliteal artery
operatively when the dorsalis pedis pulse the
graft
performed.
was
ankle was 70 mm Hg when the right brachial pressure was 128/72 and pressure at the left ankle was 138 mm Hg. The serum cholesterol was 165 mg/100 ml and triglycerides 68 mg/100 ml. The blood work and urinalysis were normal. Bilateral femoral angiograms revealed medial displacement of the right popliteal artery (Fig. 5a). The preoperative diagnosis was popliteal entrapment syndrome with distal embolisation. At operation two tendinous attachments of the medial head of the gastrocnemius into the medial femoral condyle were again noted. The popliteal artery was found to lie between these two tendons and was compressed. Distal to the compression the artery was dilated. The origins of the medial head of the gastrocnemius were divided. An operative angiogram was performed which demonstrated an intraluminal filling defect in the popliteal artery. The anterior tibial artery was occluded and there was partial occlusion of the posterior tibial artery (Fig. 6). The peroneal artery was patent. An endarterectomy was performed and saphenous vein patch was applied. Postoperatively the posterior tibial pulse was normal. The postoperative pressure was 100 mm Hg when the right brachial blood pressure was 119/71 mm Hg. The postoperative angiogram demonstrated patency of the reconstruction (Fig. 7).
saphenous vein
a
functioning graft
Hg when the right brachial blood
mm
and
The vein
sympathectomy
revealed
position (Fig. 4).
in its normal
excised
continuity.
between the two heads of the
lumbar
operative angiograms
operative angiogram with vein graft in normal position.
then
was
inserted to restore
was
FIG. 4. Case 1. F. N. Post-
'
Ann. SLII-g. . Nlai-ch 1977
later
At
he
was mm
ankle
was
125
118/85
mm
Hg.
revealed
artery
portion
was
a
almost
completely occluded with thrombus. On microscopic examination there new
was
minimal atheroma and the lumen contained both old and
thrombus.
Case 2. L. H.,
until
a
19-year-old student, had been previously normal
prior
months
4
presentation
to
before being foot and non.
seen
right leg
popliteal pulse pulses
were
was
was
grade
one
began
to
suffer
block. One month
he noted coldness and numbness in the
pain in the great
toe
Physical examination
whose
he
when
pain in the right calf after walking about
associated with
revealed
cooler
than
a
healthy appearing
the
left
normal. The dorsalis one
out
of four.
right
Raynaud's phenome-
below
young
man
knee.
The
the
pedis and posterior tibial
The
pressure
at
the
right
FIGS. 5a and b. Case 2. L. H. Bilateral femoral angiograms: right popliteal artery is displaced medially. (b) left-normal popliteal artery in the popliteal fossa.
Vol. 185 * No. 3
POPLITEAL ENTRAPMENT SYNDROME
345
Search of the Literature Articles available to the authors were surveyed and a summary of patient data is listed in Table 1. We were able to compile information on a total of 47 patients: 40 were male, ranging in age from 12 to 64 years; 5 were female, ranging in age from 17 to 41 years; and one patient had neither sex nor age
FIG. 7. Case 2. L. H. Postoperative angiogram-popliteal artery lying in its normal position with the vein patch.
indicated. Of the 40 males reported, 34 were Type 1 (Fig. 8b), i.e., where the artery passes medial to the medial head of the gastrocnemius muscle,24 6 males were Type 2, i.e., where the artery is in its normal course and is compressed by an aberrant origin of the gastrocnemius or the plantaris muscle24 and in one male patient the type was not given. Three of the 5 female patients were classified as Type 1 and the remaining two were Type 2. There were 5 patients in which the arterial entrapment was bilateral. Three were male and one was female and they were all 21 years or under. In one patient with bilateral entrapment the sex, type and age of the patient were not given and there was one patient reported as having unilateral entrapment of both the popliteal artery and vein.8
Discussion In reviewing the literature dealing with the developFIG. 6. Case 2. L. H. Operative angiogram. upper arrow-denotes filling defect in popliteal artery. lower arrows-denote occlusion of the anterior tibial artery and intraluminal filling defects in the posterior tibial artery.
ment of the popliteal artery30 and the gastrocnemius muscle3 it appears that the sequencing of events may explain the anomalous entrapment of the popliteal artery. The embryonic superficialis poplitea artery or better still the newly formed popliteal artery lies
346
Ann. Sirg.
GIBSON AND OTHERS
*
March 1977
TABLE 1. Siummary of Popliteal Entrapmenit Types*. with the Age and Sex of Patients from the Literature Female
Male
11-20
yr
Type 2
Type I
Type 2
Type I
Patient Age (Decade)
No.
Reference
No.
Reference
No.
12
1,3.6,20-24,
1
12
1
No.
Reference
Total
24
2
17.24
15
21
0
8
0
5
0
11
Reference
26.27
yr
6
6,21.26.2s.31
1
14
1
31-40 yr
3
4.18.35
2
4.13
0
41-50
8
7,1,15.6,24,4
29,34
1
21-30
yr
9
33.34
51-60yr 61-70 yr Total
0
0
0
2
1
0
0
0
1
34
6
3
2
45 It
4
2.19.27
It T
As defined by Insua. et al. 1970. 24-year-old male, type unknown.14 Neither sex nor age given but was a type 2.6
posterior to the popliteus muscle at about the time the medial head of the gastrocnemius transverses the popliteal fossa in its normal migration from the lateral side of the leg to the medial epicondyle of the femur. It would seem that the migrating medial head of the gastrocnemius muscle normally misses the newly formed popliteal artery and consequently lies in its normal anatomical position (Fig. 8a). However, with a majority of the cases reported in the literature revealing the popliteal artery entraped by the medial head of the gastrocnemius, it strongly suggests that for some reason, whether it is an enhancement in develop-
ment of the artery or a delay in the migration of the medial head of the gastrocnemius, the artery is swept
along with the medial head (Fig. 8b). The lateral head, to the best of our knowledge, has not been implicated. This is probably due to the fact that by the 20 mm stage the lateral head of the muscle is attached to the
lateral epicondyle of the femur and the poplitea superficialis has not fully completed its development until the 22 mm stage of fetal growth. In our series of 86 dissected specimens we found two unilateral entrapments of both popliteal vessels and one bilateral entrapment of both vessels by a slip of the
popliteal vein & artery
popliteal artery entraped between the medial condyle of the femur and the medial head of the gastrocnemius muscle
,medial head
gastrocnemius
B
FIG. 8a and b. (a) The normal vascular arrangement in the left popliteal fossa. (b) The most common type of popliteal artery entrapment found, in which the medial head of the gastrocnemius has in its development migration (arrow) entrapped the popliteal artery.
Vol. 85 * No. 3
POPLITEAL ENTRAPMENT SYNDROME
medial head of the gastrocnemius muscle (Type 1). It was found that the deceased patients had complained of intermittent claudication of their affected limbs. This clearly points out that entrapments of these vessels are still being missed. The authors still believe that this anomally is rare, probably with three or four new cases being reported a year. Both of our surgical cases were Type 1 with the aberrant portion of the medial head of the gastrocnemius being inserted more lateral than usual. Clinically, the most common presentation is progressive calf claudication. Twice it has been noted that the patient suffered from claudication while walking, but was asympatomatic while running.5 One patient had mild symptoms while walking and they could be increased while sitting with the foot acutely dorsiflexed. Depending upon the patency of the popliteal artery the pedal pulses may or may not be palpable. The popliteal pulse may also be aberrant. In cases associated with poststenotic dilatation, a fullness in the popliteal fossa may be present. Servello3l was the first to note that, with severe dorsiflexion of the foot, the pedal pulses diminish. In both patients there was occlusion of branches of the popliteal artery distal to the site of the entrapment. Stenosis and occlusion of the branches of the popliteal artery is likely due to distal embolisation, secondary to thrombosis at the site of entrapment. Many of the variations and degrees of entrapment by the medial head of the gastrocnemius is due mainly to the variability of its attachment to the femur.5'19 However, the artery has been found piercing the medial head of the muscle as found in our three dissected specimens and by others.'0'21 The case described by Love and Whelan26 where the popliteal artery passed anterior to the popliteus muscle can be explained by the fact that the poplitea superficialis artery probably failed to develop (Fig. 1). Therefore, the poplitea profunda artery persisted anterior to the popliteus muscle, remaining as the major blood supply to the leg. Another variation is where the two heads of the muscle fail to develop and instead it attaches to the lateral epicondyle of the femur, whereas a tendinous slip crosses the vessels posteriorly and attaches to the medial epicondyle of the femur producing an entrap-
ment.'4 It appears odd that there is only one previous case reported where both the popliteal artery and vein are entrapped.8 This may be because the limb veins, which are true accompanying vessels to the arteries, are the last to develop,'5 and therefore would normally be unavailable for entrapment. However, in all three of our dissected specimens the popliteal vein was entrapped along with the artery.
347
Acknowledgments The authors would like to thank M. Strickler of Michigan State University and S. Bradbury of The University of Manitoba for their technical assistance in preparing the specimens.
References 1. Albertazzi, V. J., Elliott, T. E., and Kennedy, J. A.: Popliteal Artery Entrapment. Angiology, 20:119, 1969. 2. Arnold, G.: Seltene Gefass-und Muskelanomalien am Bein. Anat. Anz. Bd., 123:471, 1968. 3. Bardeen, C. R.: Development and Variation of the Nerves and the Musculature of the Inferior Extremity and of the Neighboring Regions of the Trunk in Man. Am. J. Anat., 6: 259-390, 1907. 4. Brightmore, T. G., and Smellie, W. A.: Popliteal Artery Entrapment. Br. J. Surg., 58:481, 1971. 5. Carter, A. E., and Eban, R.: A Case of Bilateral Developmental Abnormality of the Popliteal Arteries and Gastrocnemius Muscles. Br. J. Surg., 51:518, 1964. 6. Chambardel-Dubreuil, L.: Variations des Arteres du Pelvis et du Membre Inferieur. Paris, Masson & Cie., 1925. 7. Chavatzas, D., Barabas, A., and Martin, P.: Popliteal-artery Entrapment. Lancet, 2:181, 1973. 8. Darling, R. C., Buckley, C. J., Abbott, W. M., and J. K. Raines: Intermittent Claudication in Young Athletes: Popliteal Artery Entrapment Syndrome. J. Trauma, 14:543, 1974. 9. Delaney, T. A., and Gonzalez, L. L.: Occlusion of Popliteal Artery Due to Muscular Entrapment. Surgery, 69:97, 1971. 10. Edmondson, H. T., and Crowe, J. A.: Popliteal Arterial and Venous Entrapment. Am. Surg., 38:657, 1972. 11. Evans, H. M.: The Development of the Vascular System. In: Human Embryology, (Ed.) Keibel and Mall. Philadelphia, J. B. Lippincott Co., Vol. 2, 1912; pp. 570-709. 12. Ezzet, F., and Yettra, M.: Bilateral Popliteal Artery Entrapment: Case Report and Observations. J. Cardiovasc. Surg., 12: 71, 1971. 13. Fontanetta, A. P., Kirshbom, I., Fisher, M. M., et al.: Popliteal Artery Entrapment: Lateral Deviation and Compression of Artery. Vasa, 3(4):399, 1974. 14. Gallagher, E. G., and Hudson, T. L.: Popliteal Artery Entrapment. Am. J. Surg., 128:88, 1974. 15. Gaylis, H.: Popliteal Artery Entrapment Syndrome. S. Afr. Med. J., 46:1071, 1972. 16. Gordon, J. A., and Dent., R. I.: Popliteal Artery Entrapment Syndrome. Cent. Afr. J. Med., 20:95, 1974. 17. Haimovici, H., Sprayregen, S., and Johnson, F.: Popliteal Artery Entrapment by Fibrous Band. Surgery, 72:789, 1972. 18. Hall, K. V.: Anomalous Insertion of the Medial Gastrocnemic Head with Circulatory Complications. Arch. Pathol. Microbiol. Scand., (Suppl.) 148:53, 1961. 19. Hall, K. V.: Intravascular Gastrocnemic Insertion. Acta. Chir.
Scand., 128:193, 1964. 20. Hamming, J. J.: Intermittent Claudication at an Early Age, Due to an Anomalous Course of the Popliteal Artery. Agiology, 10:369, 1959. 21. Hamming, J. J., and Vink, U.: Obstruction of the Popliteal Artery at an Early Age. J. Cardiovasc. Surg., 6:516, 1965. 22. Harris, J. D., and Jepson, R. P.: Entrapment of the Popliteal Artery. Surgery, 69:246, 1971. 23. Husni, E. A., and Ryu, C. K.: Entrapment of the Popliteal Artery and its Management. Angiology, 22:380, 1971. 24. Insua, J. A., Young, J. R., and Humphries, A. W.: Popliteal Artery Entrapment Syndrome. Arch. Surg., 101:771, 1970. 25. Lewis, W. H.: The Development of the Muscular System. In: Human Embryology, (Ed.) Keibel and Mall. Philadelphia, J. B. Lippincott Co., Vol. 1, 1912; pp. 494-505. 26. Love, J. W., and Whelhan, T. J.: Popliteal Entrapment Syndrome. Am. J. Surg., 109:620, 1965. 27. Mahler, F., Brunner, U., and Bollinger, A.: Das Kompressions-
348
28. 29.
30. 31.
GIBSON AND OTHERS
syndrom der arteria poplitea. Deutsch. Med. Wscher., 94: 786, 1969. Mentha, C.: Malposition et Stenose extrinseque de l'Artere poplitee par la Compression musculotendineuse du Jumeau interne. J. Chir., 91:489, 1966. Rich, N. M., and Hughes, C. W.: Popliteal Artery and Vein Entrapment. Am. J. Surg., 113:696, 196/. Senior, H. D.: The Development of the Arteries of the Human Lower Extremity. Am. J. Anat., 25:55, 1919. Servello, M.: Clinical Syndrome of Anomalous Position of the Popliteal Artery. Circulation, 26:885, 1962.
Ann. SLirg. * March 1977
32. Stuart, T. P. A.: Note on a Variation in the Course of the Popliteal Artery. J. Anat. Physiol., 13:162, 1879. 33. Teniere, P., Lecossais, J.-C., Testart, J., and Jouanneau, P.: Syndrome de 1' "Artere Poplitee Piegee." J. Chir., 102:465, 1971. 34. Trede, M., Laubach, K., Saggan, W., and Perera, R.: A poplitea-Verschluss durch Verlaufsanomalie. Thoraxchirurgie, 20:393, 1972. 35. Turner, G. R., Gosney, W. G., Ellingson, W., and Gaspar, M.: Popliteal Artery Entrapment Syndrome. JAMA, 208:692, 1969.
A probable cause of popliteal artery entrapment is proposed. The medial head of the gastrocnemius muscle during its embryological development crosses the popliteal fossa from lateral to medial. It is proposed that the migrating medial head carries the popliteal artery and vein across the fossa and entraps them against the medial condyle of the femur. Dissection of 86 anatomical specimens revealed two cases of unilateral and one case of bilateral entrapment of both popliteal vessels. Two surgical cases of popliteal entrapment are presented. This entrapment syndrome is a remedial cause of claudication and when considered, it is readily diagnosed and surgical correction is effective. Because of distal embolisation and occlusions, early recognition and treatment is desirable. Forty-seven cases from the literature are reviewed as to the entrapment type and the age and sex of the patients. Submitted for publication June 18, 1976. Department of Surgery, Health Sciences Centre, 700 William Avenue, Winnipeg, Manitoba, Canada R3E OW3 *
From the Departments of Anatomy, University of Manitoba, Faculty of Medicine, Winnipeg, and Michigan State University, East Lansing, Michigan, U.S.A., and the Department of Surgery, University of Manitoba, Health Sciences Centre, Winnipeg, Canada
SINCE the first reported case by Stuart,32 over 95 years ago there has been an ever increasing interest and awareness of the entrapment syndrome of the popliteal artery. The entrapment of the popliteal artery is a rare cause of ischemia of the lower limb. However, to date there have been well over 50 reported cases of this syndrome in the literature. This syndrome typically involves either an aberrant path for the popliteal vessels or an aberrant attachment of the gastrocnemius or plantaris muscles over the normally popl
i tea profunda.
a.
FEMUR
medial inferior genicular a.
ADULT POPLITEAL A.
T I B IA
FIG. 1. A schematic medial view of the embryological development of the popliteal artery (modified from Senior, 1919).
poplitea superficialis a.]
posterior tibial recurrent a.
peroneal a.
anterior tibi recurrent a.
posterior tibial a.
anterior a.
=
popl iteus muscle
=
tibialis posterior muscle
= = =
341
degenerated portion of the poplitea profunda a.
342
GIBSON AND OTHERS
Ann. Stirg. * Mai-ch 1977
artery forming the lower segment (Fig. 1). Originally the major blood supply to the leg is via the poplitea profunda artery, passing between the anterior surface of the popliteus muscle and the posterior surface of the tibia (Fig. 1). However, by the 22 mm stage the superficialis poplitea artery is sufficiently well developed and begins to act as an additional blood supply to the leg. By the 24.5 mm stage the segment of the poplitea profunda artery passing anterior to the popliteus muscle has ceased to exist. Beginning at this stage of development the leg is supplied by the superficialis poplitea artery lying on the posterior surface of the popliteus muscle. Therefore, the main arterial channel through the popliteal region has been transferred from the anterior to the posterior surface of the popliteus muscle (Fig. 1).
FIGS. 2a and b. Case 1. F. N. (left) There is marked medial displaceof the popliteal artery at the level of the femoral condyle. (right) The flow contrast media is delayed in the portion of the popliteal artery which is displaced. ment
positioned vessels.24 In either case, the popliteal or accompanied by its vein are compressed against the condyle of the femur, producing intermittent claudication of the affected limb as the most common patient complaint. The purpose of this paper is to explain embryologically a possible cause of this entrapment, and its incidence in a population of dissected human specimens, and also to report on two clinical cases in which the presence of multiple distal occlusions emphasizes the importance of early diagnosis and artery either alone
treatment.
Embryology of the Popliteal Artery The formation of the adult human popliteal artery, according to Senior,30 results from the union of two embryonic vessels; the poplitea profunda artery forming the upper segment and the superficialis poplitea
Embryology of the gastrocnemius muscle At about the time the major arterial supply to the leg changes from the anterior to the posterior surface of the popliteus muscle, the development of the gastrocnemius muscle is well advanced.3'25 Earlier detection reveals that the anlage of the gastrocnemius is attached inferiorly to the developing calcaneus and by the 14 mm stage (5.5 wks) the medial and lateral heads of the muscle are distinct. At this time the two heads of the gastrocnemius are in the active process of migrating from their original lateral position in the developing leg, superiorly towards their adult attachments on the femur.3'25 By the 20 mm stage (7 wks) the lateral head of the gastrocnemius has formed a tendinous attachment to the lateral epicondyle of the femur. However, at this stage the medial head of the gastrocnemius has not yet attained its femoral attachment.3 It continues to migrate medially and superiorly, eventually attaching to the medial epicondyle of the femur, usually at a level more cranial than the attachment of the lateral head. Dissected specimens From among the specimens willed to the Departments of Anatomy at The University of Manitoba and Michigan State University a total of 86 human specimens were selected for dissection. Of these, 22 were female. In each specimen the popliteal region of both limbs was dissected to determine if the popliteal vessels took a normal course through the popliteal fossa or whether they were compressed by an aberrant muscle slip or tendon. In three specimens dissected, there were popliteal vessels taking a deviate course through the popliteal region. Two of these specimens, a 72-year-old male and a 85-year-old female, at the time of their death had a unilateral entrapment of the right popliteal vessels. The third
343
POPLITEAL ENTRAPMENT SYNDROME
Vol. 185 * No. 3
I
FIG. 3a. Case 1. F. N.
Operative photograph -the popliteal artery emerges from between the two portions of the origin of the medial head of the gastrocnemius (at the point of the scissors). Distal to this, the artery is moderately dilated.
specimen, a 66 year old male had a bilateral entrapment of both popliteal vessels. In all three cases the vessels were passing through the medial head of the gastrocnemius muscle. Histological sections of the entrapped vessels showed no occlusion of the lumen and essentially were normal. The records of the deceased were scrutinized and it was found that each had complained of mild intermittent claudication in the affected limb(s) for a number of years.
drome. At operation the popliteal artery at the level of the knee joint lay between two portions of the medial head of the gastrocnemius muscle and was compressed by the tendinous lateral portion. Just distal to the site of compression the artery was slightly dilated (Fig. 3).
I
Case Reports Case 1: F.N., a 43-year-old school inspector who was previously well, presented in May 1968 complaining of claudication in the right calf and numbness and tingling in his right foot on walking. He was a non-smoker and there was no history of cardiac or cerebral disease. On physical examination his blood pressure was 120/80, pulse was 72 and regular. The right popliteal pulse was graded three out of four. The dorsalis pedis and posterior tibial pulses were absent. The right leg below the knee was cooler than the left. All other peripheral pulses were normal. The systolic pressure at the right ankle was 85 mm Hg and at the left ankle 135 mm Hg when the right brachial blood pressure was 122/80 mm Hg. The serum cholesterol was 155 mg/100 ml and triglycerides were 149 mg/100 ml. A right femoral angiogram revealed normal femoral and iliac arteries. At the level of the femoral condyles the popliteal artery was displaced rather abruptly medially and returned to its normal position just below the level of the knee joint (Fig. 2a and b). The artery was narrowed at the site of the displacement with an irregular lumen. The anterior tibial artery was occluded. The diagnosis preoperatively was thrombosed popliteal aneurysm with distal propagation of the thrombus or popliteal entrapment syn-
"
,/
\
\\
/
l!
/./-
FIG. 3b. Line diagram of operative findings. (1) Medial tendinous origin of medial head of gastrocnemius. (2) Lateral muscular origin of medial head of the gastrocnemius. (3) Popliteal artery lying between the two origins of the medial head of the gastrocnemius.
GIBSON AND OTHERS
344
-,.e6J,:
dilated
The
graft
portion
in the normal
position
right
muscle. A
its normal
lying 10
There
Hg.
a
were
The left
position.
The
right
pressure
time
of the
asymptomatic.
followup
three
systolic
The
Pathological
examination
diameter
of
1.3
a
of cm.
pressure
right
the
resected
The
dilated
in
was
128/80
mm
days post-
first detected.
was
was
pressure
13
half years
pressure at the
Hg when the right brachial blood maximum
and
right
patent and
was
pedal pulses palpable until
no
The post-
the
was
systolic
ankle
placed
was
gastrocnemius
on
popliteal artery
operatively when the dorsalis pedis pulse the
graft
performed.
was
ankle was 70 mm Hg when the right brachial pressure was 128/72 and pressure at the left ankle was 138 mm Hg. The serum cholesterol was 165 mg/100 ml and triglycerides 68 mg/100 ml. The blood work and urinalysis were normal. Bilateral femoral angiograms revealed medial displacement of the right popliteal artery (Fig. 5a). The preoperative diagnosis was popliteal entrapment syndrome with distal embolisation. At operation two tendinous attachments of the medial head of the gastrocnemius into the medial femoral condyle were again noted. The popliteal artery was found to lie between these two tendons and was compressed. Distal to the compression the artery was dilated. The origins of the medial head of the gastrocnemius were divided. An operative angiogram was performed which demonstrated an intraluminal filling defect in the popliteal artery. The anterior tibial artery was occluded and there was partial occlusion of the posterior tibial artery (Fig. 6). The peroneal artery was patent. An endarterectomy was performed and saphenous vein patch was applied. Postoperatively the posterior tibial pulse was normal. The postoperative pressure was 100 mm Hg when the right brachial blood pressure was 119/71 mm Hg. The postoperative angiogram demonstrated patency of the reconstruction (Fig. 7).
saphenous vein
a
functioning graft
Hg when the right brachial blood
mm
and
The vein
sympathectomy
revealed
position (Fig. 4).
in its normal
excised
continuity.
between the two heads of the
lumbar
operative angiograms
operative angiogram with vein graft in normal position.
then
was
inserted to restore
was
FIG. 4. Case 1. F. N. Post-
'
Ann. SLII-g. . Nlai-ch 1977
later
At
he
was mm
ankle
was
125
118/85
mm
Hg.
revealed
artery
portion
was
a
almost
completely occluded with thrombus. On microscopic examination there new
was
minimal atheroma and the lumen contained both old and
thrombus.
Case 2. L. H.,
until
a
19-year-old student, had been previously normal
prior
months
4
presentation
to
before being foot and non.
seen
right leg
popliteal pulse pulses
were
was
was
grade
one
began
to
suffer
block. One month
he noted coldness and numbness in the
pain in the great
toe
Physical examination
whose
he
when
pain in the right calf after walking about
associated with
revealed
cooler
than
a
healthy appearing
the
left
normal. The dorsalis one
out
of four.
right
Raynaud's phenome-
below
young
man
knee.
The
the
pedis and posterior tibial
The
pressure
at
the
right
FIGS. 5a and b. Case 2. L. H. Bilateral femoral angiograms: right popliteal artery is displaced medially. (b) left-normal popliteal artery in the popliteal fossa.
Vol. 185 * No. 3
POPLITEAL ENTRAPMENT SYNDROME
345
Search of the Literature Articles available to the authors were surveyed and a summary of patient data is listed in Table 1. We were able to compile information on a total of 47 patients: 40 were male, ranging in age from 12 to 64 years; 5 were female, ranging in age from 17 to 41 years; and one patient had neither sex nor age
FIG. 7. Case 2. L. H. Postoperative angiogram-popliteal artery lying in its normal position with the vein patch.
indicated. Of the 40 males reported, 34 were Type 1 (Fig. 8b), i.e., where the artery passes medial to the medial head of the gastrocnemius muscle,24 6 males were Type 2, i.e., where the artery is in its normal course and is compressed by an aberrant origin of the gastrocnemius or the plantaris muscle24 and in one male patient the type was not given. Three of the 5 female patients were classified as Type 1 and the remaining two were Type 2. There were 5 patients in which the arterial entrapment was bilateral. Three were male and one was female and they were all 21 years or under. In one patient with bilateral entrapment the sex, type and age of the patient were not given and there was one patient reported as having unilateral entrapment of both the popliteal artery and vein.8
Discussion In reviewing the literature dealing with the developFIG. 6. Case 2. L. H. Operative angiogram. upper arrow-denotes filling defect in popliteal artery. lower arrows-denote occlusion of the anterior tibial artery and intraluminal filling defects in the posterior tibial artery.
ment of the popliteal artery30 and the gastrocnemius muscle3 it appears that the sequencing of events may explain the anomalous entrapment of the popliteal artery. The embryonic superficialis poplitea artery or better still the newly formed popliteal artery lies
346
Ann. Sirg.
GIBSON AND OTHERS
*
March 1977
TABLE 1. Siummary of Popliteal Entrapmenit Types*. with the Age and Sex of Patients from the Literature Female
Male
11-20
yr
Type 2
Type I
Type 2
Type I
Patient Age (Decade)
No.
Reference
No.
Reference
No.
12
1,3.6,20-24,
1
12
1
No.
Reference
Total
24
2
17.24
15
21
0
8
0
5
0
11
Reference
26.27
yr
6
6,21.26.2s.31
1
14
1
31-40 yr
3
4.18.35
2
4.13
0
41-50
8
7,1,15.6,24,4
29,34
1
21-30
yr
9
33.34
51-60yr 61-70 yr Total
0
0
0
2
1
0
0
0
1
34
6
3
2
45 It
4
2.19.27
It T
As defined by Insua. et al. 1970. 24-year-old male, type unknown.14 Neither sex nor age given but was a type 2.6
posterior to the popliteus muscle at about the time the medial head of the gastrocnemius transverses the popliteal fossa in its normal migration from the lateral side of the leg to the medial epicondyle of the femur. It would seem that the migrating medial head of the gastrocnemius muscle normally misses the newly formed popliteal artery and consequently lies in its normal anatomical position (Fig. 8a). However, with a majority of the cases reported in the literature revealing the popliteal artery entraped by the medial head of the gastrocnemius, it strongly suggests that for some reason, whether it is an enhancement in develop-
ment of the artery or a delay in the migration of the medial head of the gastrocnemius, the artery is swept
along with the medial head (Fig. 8b). The lateral head, to the best of our knowledge, has not been implicated. This is probably due to the fact that by the 20 mm stage the lateral head of the muscle is attached to the
lateral epicondyle of the femur and the poplitea superficialis has not fully completed its development until the 22 mm stage of fetal growth. In our series of 86 dissected specimens we found two unilateral entrapments of both popliteal vessels and one bilateral entrapment of both vessels by a slip of the
popliteal vein & artery
popliteal artery entraped between the medial condyle of the femur and the medial head of the gastrocnemius muscle
,medial head
gastrocnemius
B
FIG. 8a and b. (a) The normal vascular arrangement in the left popliteal fossa. (b) The most common type of popliteal artery entrapment found, in which the medial head of the gastrocnemius has in its development migration (arrow) entrapped the popliteal artery.
Vol. 85 * No. 3
POPLITEAL ENTRAPMENT SYNDROME
medial head of the gastrocnemius muscle (Type 1). It was found that the deceased patients had complained of intermittent claudication of their affected limbs. This clearly points out that entrapments of these vessels are still being missed. The authors still believe that this anomally is rare, probably with three or four new cases being reported a year. Both of our surgical cases were Type 1 with the aberrant portion of the medial head of the gastrocnemius being inserted more lateral than usual. Clinically, the most common presentation is progressive calf claudication. Twice it has been noted that the patient suffered from claudication while walking, but was asympatomatic while running.5 One patient had mild symptoms while walking and they could be increased while sitting with the foot acutely dorsiflexed. Depending upon the patency of the popliteal artery the pedal pulses may or may not be palpable. The popliteal pulse may also be aberrant. In cases associated with poststenotic dilatation, a fullness in the popliteal fossa may be present. Servello3l was the first to note that, with severe dorsiflexion of the foot, the pedal pulses diminish. In both patients there was occlusion of branches of the popliteal artery distal to the site of the entrapment. Stenosis and occlusion of the branches of the popliteal artery is likely due to distal embolisation, secondary to thrombosis at the site of entrapment. Many of the variations and degrees of entrapment by the medial head of the gastrocnemius is due mainly to the variability of its attachment to the femur.5'19 However, the artery has been found piercing the medial head of the muscle as found in our three dissected specimens and by others.'0'21 The case described by Love and Whelan26 where the popliteal artery passed anterior to the popliteus muscle can be explained by the fact that the poplitea superficialis artery probably failed to develop (Fig. 1). Therefore, the poplitea profunda artery persisted anterior to the popliteus muscle, remaining as the major blood supply to the leg. Another variation is where the two heads of the muscle fail to develop and instead it attaches to the lateral epicondyle of the femur, whereas a tendinous slip crosses the vessels posteriorly and attaches to the medial epicondyle of the femur producing an entrap-
ment.'4 It appears odd that there is only one previous case reported where both the popliteal artery and vein are entrapped.8 This may be because the limb veins, which are true accompanying vessels to the arteries, are the last to develop,'5 and therefore would normally be unavailable for entrapment. However, in all three of our dissected specimens the popliteal vein was entrapped along with the artery.
347
Acknowledgments The authors would like to thank M. Strickler of Michigan State University and S. Bradbury of The University of Manitoba for their technical assistance in preparing the specimens.
References 1. Albertazzi, V. J., Elliott, T. E., and Kennedy, J. A.: Popliteal Artery Entrapment. Angiology, 20:119, 1969. 2. Arnold, G.: Seltene Gefass-und Muskelanomalien am Bein. Anat. Anz. Bd., 123:471, 1968. 3. Bardeen, C. R.: Development and Variation of the Nerves and the Musculature of the Inferior Extremity and of the Neighboring Regions of the Trunk in Man. Am. J. Anat., 6: 259-390, 1907. 4. Brightmore, T. G., and Smellie, W. A.: Popliteal Artery Entrapment. Br. J. Surg., 58:481, 1971. 5. Carter, A. E., and Eban, R.: A Case of Bilateral Developmental Abnormality of the Popliteal Arteries and Gastrocnemius Muscles. Br. J. Surg., 51:518, 1964. 6. Chambardel-Dubreuil, L.: Variations des Arteres du Pelvis et du Membre Inferieur. Paris, Masson & Cie., 1925. 7. Chavatzas, D., Barabas, A., and Martin, P.: Popliteal-artery Entrapment. Lancet, 2:181, 1973. 8. Darling, R. C., Buckley, C. J., Abbott, W. M., and J. K. Raines: Intermittent Claudication in Young Athletes: Popliteal Artery Entrapment Syndrome. J. Trauma, 14:543, 1974. 9. Delaney, T. A., and Gonzalez, L. L.: Occlusion of Popliteal Artery Due to Muscular Entrapment. Surgery, 69:97, 1971. 10. Edmondson, H. T., and Crowe, J. A.: Popliteal Arterial and Venous Entrapment. Am. Surg., 38:657, 1972. 11. Evans, H. M.: The Development of the Vascular System. In: Human Embryology, (Ed.) Keibel and Mall. Philadelphia, J. B. Lippincott Co., Vol. 2, 1912; pp. 570-709. 12. Ezzet, F., and Yettra, M.: Bilateral Popliteal Artery Entrapment: Case Report and Observations. J. Cardiovasc. Surg., 12: 71, 1971. 13. Fontanetta, A. P., Kirshbom, I., Fisher, M. M., et al.: Popliteal Artery Entrapment: Lateral Deviation and Compression of Artery. Vasa, 3(4):399, 1974. 14. Gallagher, E. G., and Hudson, T. L.: Popliteal Artery Entrapment. Am. J. Surg., 128:88, 1974. 15. Gaylis, H.: Popliteal Artery Entrapment Syndrome. S. Afr. Med. J., 46:1071, 1972. 16. Gordon, J. A., and Dent., R. I.: Popliteal Artery Entrapment Syndrome. Cent. Afr. J. Med., 20:95, 1974. 17. Haimovici, H., Sprayregen, S., and Johnson, F.: Popliteal Artery Entrapment by Fibrous Band. Surgery, 72:789, 1972. 18. Hall, K. V.: Anomalous Insertion of the Medial Gastrocnemic Head with Circulatory Complications. Arch. Pathol. Microbiol. Scand., (Suppl.) 148:53, 1961. 19. Hall, K. V.: Intravascular Gastrocnemic Insertion. Acta. Chir.
Scand., 128:193, 1964. 20. Hamming, J. J.: Intermittent Claudication at an Early Age, Due to an Anomalous Course of the Popliteal Artery. Agiology, 10:369, 1959. 21. Hamming, J. J., and Vink, U.: Obstruction of the Popliteal Artery at an Early Age. J. Cardiovasc. Surg., 6:516, 1965. 22. Harris, J. D., and Jepson, R. P.: Entrapment of the Popliteal Artery. Surgery, 69:246, 1971. 23. Husni, E. A., and Ryu, C. K.: Entrapment of the Popliteal Artery and its Management. Angiology, 22:380, 1971. 24. Insua, J. A., Young, J. R., and Humphries, A. W.: Popliteal Artery Entrapment Syndrome. Arch. Surg., 101:771, 1970. 25. Lewis, W. H.: The Development of the Muscular System. In: Human Embryology, (Ed.) Keibel and Mall. Philadelphia, J. B. Lippincott Co., Vol. 1, 1912; pp. 494-505. 26. Love, J. W., and Whelhan, T. J.: Popliteal Entrapment Syndrome. Am. J. Surg., 109:620, 1965. 27. Mahler, F., Brunner, U., and Bollinger, A.: Das Kompressions-
348
28. 29.
30. 31.
GIBSON AND OTHERS
syndrom der arteria poplitea. Deutsch. Med. Wscher., 94: 786, 1969. Mentha, C.: Malposition et Stenose extrinseque de l'Artere poplitee par la Compression musculotendineuse du Jumeau interne. J. Chir., 91:489, 1966. Rich, N. M., and Hughes, C. W.: Popliteal Artery and Vein Entrapment. Am. J. Surg., 113:696, 196/. Senior, H. D.: The Development of the Arteries of the Human Lower Extremity. Am. J. Anat., 25:55, 1919. Servello, M.: Clinical Syndrome of Anomalous Position of the Popliteal Artery. Circulation, 26:885, 1962.
Ann. SLirg. * March 1977
32. Stuart, T. P. A.: Note on a Variation in the Course of the Popliteal Artery. J. Anat. Physiol., 13:162, 1879. 33. Teniere, P., Lecossais, J.-C., Testart, J., and Jouanneau, P.: Syndrome de 1' "Artere Poplitee Piegee." J. Chir., 102:465, 1971. 34. Trede, M., Laubach, K., Saggan, W., and Perera, R.: A poplitea-Verschluss durch Verlaufsanomalie. Thoraxchirurgie, 20:393, 1972. 35. Turner, G. R., Gosney, W. G., Ellingson, W., and Gaspar, M.: Popliteal Artery Entrapment Syndrome. JAMA, 208:692, 1969.
