A Pseudoaneurysm of the Medial Inferior Genicular Artery  following Knee Trauma : A Rare Entity   

Yasser Mohamed Abdelkader Hossni¹, Tariq Wahab Khanzada*, Syed Abdul Samad², Tagalsir Abdallah Loqman, Rafiq Ahmed³, Hood Al Saqri ⁴, Islam Ahmed Mohammadin Ismail ⁵ , Mustafa Rashid Al Khaifi ⁶, Nahid Mubarak Al Qanubi ⁷

1,2,3. Department of General Surgery , Rustaq Hospital, Sultanate of Oman.

4,5. Department of Orthopedics , Rustaq Hospital, Sultanate of Oman.

6,7. Department of Radiology , Rustaq Hospital , Sultanate of Oman.

*Correspondence to: Tariq Wahab Khanzada, Senior Consultant Surgeon, Department of General Surgery, Rustaq Hospital, Sultanate of Oman. Email: tariqwahab@yahoo.com

Copyright
© 2023: Tariq Wahab Khanzada. This is an open access article distributed under the Creative Commons Attribution  License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original    work is properly cited.

Received:  10  November 2023

Published: 02 January 2024

Abstract

Pseudoaneurysm of genicular arteries  are  extremely rare clinical entity. Usually these are encountered in young  and athletes who are more prone  to  knee trauma and  requiring  reconstructive orthopedic procedures. We report a case of pseudoaneurysm  of genicular artery  in a 4-year-old child  following trauma. Radiographic  imaging included a doppler ultrasound and  CT angiography. Pseudoaneurysm  was successfully treated  with ligation of feeding vessel.   The causes , presentation, diagnosis, and management of genicular arteries are discussed in this case report.

Keywords:  Pseudoaneurysm, Genicular artery, Ligation

Introduction

A pseudoaneurysm, also termed a false aneurysm, is a leakage of arterial blood from an artery into the surrounding tissue with a persistent communication between the originating artery and the resultant adjacent cavity.¹  Pseudo aneurysm around knee usually  result from  Total knee arthroplasty though the incidence of this complication is not that much.²  A high index of suspicion  usually helps  in early identification  and treatment. However, trauma around knee may also result in pseudoaneurysm formation.

We   describe a case of pseudoaneurysm  of inferior genicular artery  resulting from trauma on knee in a  four years old child.

Case Presentation

A four  years old child  was brought in surgical clinic  with  swelling at  the left knee. The child had penetrating  trauma  two weeks ago at home and was seen at local health center where wound was washed and sutured.  Sutures were removed at local health center after 10 days but patient presented to surgical clinic with  painful swelling at the wound. Examination revealing  a swelling of about 2x3 cm impending to rupture ,  with over lying  skin  red, warm with blackish edges , and pulsating.(Fig:1)  Child had limited movements of left knee due to pain.

Initially a soft tissue  Ultrasound was done  revealing  a well-defined hypoechoic lesion  measuring 2.4x1.7 cm . The lesion shows ying yang sign in color doppler. (Fig:2) The lesion was continuous  with small vessels measuring  4 mm.  Findings were suggestive of  post traumatic pseudoaneurysm.

CT angiography was performed  and it revealed  partial opacification  of thick  wall cystic  lesion in front of upper tibia  measuring  about 1.9x1.8x1.9 cm  in three orthogonal dimensions and its neck was 3 mm in diameter. The lesion was communicating  with infra-genicular part of popliteal artery  at 4.2 cm proximal to its bifurcation  through a defect  of 1.4 mm in anterior wall of popliteal artery. No gross leak of contrast seen at the time of scan. CT angiography findings were consistent  of partially thrombosed medial inferior  genicular  artery pseudo aneurysm. ( Fig:3) Blood work up was normal except for C reactive protein which was  12 mg/l ( 0-5)

Parents were informed about the surgery and informed written  consent  was taken.

Incision was made on posterior border of tibia; active bleeder was encountered due to fragile tissues. Popliteal artery was  exposed and proximal control was achieved. Medial inferior genicular artery  and hematoma exposed along with damaged artery. Healthy segment of the feeding  artery  was ligated  underneath the medial collateral ligament. ( Fig:4 )  With elliptical skin incision around the wound , necrotic tissues were removed  and Hematoma evacuated. Medial collateral ligament  tear was  repaired by Ortho team Necrotic tissues were sent for culture/ sensitivity.

Post operatively patient  had uneventful  recovery.  Distal Pulses  were intact. Tissue c/s  grew  Staphylococcus aureus  and treated with  appropriate antibiotics. Patient was later followed in clinic; wound was found coopted and sutures were removed. ( Fig:5) The child was walking with normal gait post-operatively.

Fig 1: showing the pulsatile swelling and marking on incision

 Fig. 2 . Doppler Ultrasound showing Ying Yang Sign

Fig. 3: CT Angiography showing Pseudoaneurysm of Medial Inferior Genicular artery  ( red arrow)

 Fig. 4: Operative picture  of Pseudoaneurysm

Fig. 5:  postoperative picture showing complete healing of both wounds

Discussion

An arterial pseudoaneurysm also called as  false aneurysm, is caused by damage to the arterial wall, resulting in locally contained hematoma with turbulent blood flow and a neck that typically does not close spontaneously once past a certain size. Pseudoaneurysm does not contain any layers of vessel wall like true aneurysm. The commonest causes of pseudoaneurysm  are iatrogenic following arterial access for endovascular procedures, vascular anastomotic  failure, infection around vessels and trauma. Pseudoaneurysm around knee are  infrequently reported  after  Total knee Replacement   showing an incidence  up to 0.2%.³

Clinical presentation  differs from patients to patients. Those having pseudoaneurysm following Knee arthroplasty  present  with pain , difficulty in walking  and swelling. Examination   usually reveal knee  swelling   which is pulsatile  and limitation of knee movement.  Distal pulses may or may not be decreased.

The Doppler ultrasound is the first line of investigation.  Doppler Ultrasound  reveals the “Yin- Yang sign”  which indicates bidirectional flow due to swirling of blood within the pseudoaneurysm as the portion that moved toward the transducer is red and the portion that moves away from the transducer is blue.¹ Doppler ultrasound can  also evaluate for size, anatomy, and origin of pseudoaneurysms. Ultrasound is cheap , non-invasive and easily available modality of investigation .  However, CT angiography  remains  a better option for both diagnosis and treatment with embolization. Option of embolization was  not available in our case.

The different treatment options for pseudoaneurysm around the knee depends on the size  and site of aneurysm. The management options range from  Doppler guided compression percutaneous thrombin or fibrin  injection , embolization  and  surgical repair.^4,5 Various surgical repair  options include thrombectomy, oversewing, ligation, arterial wall repair  by patch , vein graft  or arterial bypass. In our case  ligation of feeding artery was  successfully done.

High  index of suspicion  should always be made  for potentially dangerous complication  around the knee which may result in limb or life threatening. It warrants especial attention for this uncommon  complication. 

References

1. Rivera PA, Dattilo JB. Pseudoaneurysm. [Updated 2022 Mar 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542244/

2.Boutchichi A, Ciornohac J, Daubresse F. Pseudoaneurysm after total knee arthroplasty: a rare complication with different possible clinical presentations. Acta Orthop Belg. 2013 Feb;79(1):16-9. PMID: 23547509.

3.Saini, P., Meena, S., Malhotra, R. et al. Pseudoaneurysm of the superior lateral genicular artery: case report of a rare complication after total knee arthroplasty. Patient Saf Surg 7, 15 (2013). https://doi.org/10.1186/1754-9493-7-15

4. Noorpuri BSW, Maxwell-Armstrong CA, Lamerton AJ. Pseudo-aneurysm  of a genicular collateral artery  complicating  total knee replacement. Eur J Vasc Endovasc Surg  1999;18: 534-535
5. Utukuri M, Harris NJ, Spencer P, Robson MJ. False aneurysm  following total knee replacement: a non-invasive  technique  for treatment. Knee 1997;4 :49-50