© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
    CASE REPORT
    Type A aortic dissection involving the superior
      mesenteric artery with peripheral malperfusion managed with a hybrid
      approach: a case report
    Mina Cheng, FRCS, FHKAM (Surgery); KY Lee, FRCS,
      FHKAM (Surgery)
     Department of Surgery, Queen Elizabeth Hospital,
      Jordan, Hong Kong
    Corresponding author: Dr Mina Cheng (minacheng0505@gmail.com)
    Case report
    A 62-year-old man presented to Queen Elizabeth
      Hospital in November 2015 with sudden-onset chest pain radiating to his
      back and left lower limb numbness for 3 hours. He had previously suffered
      a stroke from which he had made a good recovery and could walked unaided.
      There was decreased sensation of the entire left lower limb that was
      cooler than the right. All pulses over the left lower limb were absent but
      motor power was intact. He did not complain of abdominal pain and his
      abdomen was neither distended nor tender. He was haemodynamically stable,
      and auscultation revealed normal heart sounds.
    Contrast-enhanced computed tomography (CT) scan
      revealed a type A dissection from the aortic root down to the left
      external iliac artery. No haemopericardium or pericardial effusion was
      noted. Celiac artery and superior mesenteric artery (SMA) originated from
      both a true and false lumen. The origin and proximal segment of the SMA
      and celiac artery were compressed by the thrombosed false lumen (Fig
        1). Bowel wall was well enhanced. There was cranial extension of the
      dissection into the right common and internal carotid arteries. The
      cerebral arteries were still opacified. Computed tomography brain showed
      early ischaemic change in the right cerebellar hemisphere.
    
Figure 1. Contrast-enhanced computed tomography scan showing a type A dissection from the aortic root down to the left external iliac artery
Arterial blood gas analysis and serum lactate level
      were normal. Transthoracic echocardiography detected an intimal flap at
      the aortic root. Mild aortic regurgitation was present. Left ventricular
      function was good.
    The patient had a type A aortic dissection with
      left lower limb acute ischaemia. Emergency interpositional ascending
      aortic grafting was performed to close the entry site of the ascending
      aorta dissection and to re-expand the true lumen. Postoperatively, the
      patient was haemodynamically stable and all left lower limb pulses
      reappeared.
    A new CT scan of the abdomen revealed improved
      perfusion to the celiac artery. Nonetheless, the SMA remained severely
      stenotic with only a thin line of contrast enhancement evident in the true
      lumen. Enhancement of the jejunal wall was decreased. The SMA had both
      restricted inflow at the orifice and outflow due to compression by the
      thrombosed false lumen.
    Emergency endovascular stenting and open
      fenestration of the SMA was performed in the hybrid operation theatre. A
      5-French arterial sheath was inserted into the right common femoral
      artery. The true lumen orifice of the SMA was cannulated with a 5-French
      Yashiro Glidecath catheter (Terumo, Japan) and a 0.035-inch hydrophilic
      guidewire (Terumo, Japan). The 0.035-inch hydrophilic guidewire (Terumo,
      Japan) was exchanged for a Rosen guidewire (Cordis, US). The 5-French
      arterial sheath was exchanged for an 8-French Arrow-Flex guiding sheath
      (Arrow International, US). A 10-mm × 12-mm Genesis balloon expandable
      stent (Cordis, US) was deployed at the SMA orifice. Arteriogram showed
      improvement of flow at the SMA orifice only (Fig 2). Laparotomy was performed. The small and
      large bowel were not infarcted but lacked peristalsis. The SMA distal to
      the middle colic artery was bluish in appearance due to thrombosis.
      Longitudinal arteriotomy was made. All the thrombus in the false lumen was
      removed. Longitudinal fenestration was made at the dissection flap. The
      true lumen circulation was re-established with thrombectomy using a
      3-French Fogarty catheter. The arteriotomy was closed with a saphenous
      vein patch. The small bowel appeared healthy after revascularisation.
      On-table duplex ultrasonography revealed good flow along the SMA.
    
Figure 2. On-table arteriogram showing deployment of stent at the superior mesenteric artery orifice
The patient was transferred to the intensive care
      unit and extubated 4 days after surgery. He had no neurological deficits
      or abdominal symptoms. All distal pulses were normal. He recovered well
      and was discharged from hospital on aspirin 42 days after admission.
    Serial follow-up CT scans after the operation
      showed a patent SMA and celiac artery. The patient remained asymptomatic
      at a follow-up examination 2 years later.
    Discussion
    Acute dissection is one of the most lethal surgical
      emergencies of the aorta. It results from a tear in the aortic wall intima
      that extends into the media to create a false lumen and a dissection flap.
      It is categorised according to the Stanford classification. Visceral
      malperfusion occurs in 16% to 33% of cases1
      due to anterograde propagation of the dissection from the ascending aorta
      to the level of the aortic visceral branches. This leads to mesenteric
      ischaemia, organ dysfunction, and systemic metabolic abnormalities.
      Although the results of surgical treatment for acute type A aortic
      dissection have improved due to technical advances, mortality remains as
      high as 89% in the presence of visceral ischaemia.2 It has been suggested that unless pericardial tamponade
      is present, restoration of visceral perfusion by endovascular techniques
      should take precedence, especially in cases with a high degree of
      mesenteric ischaemia and metabolic disturbance.3
      This can improve metabolic status and reduce the intra-operative risk of
      subsequent dissection repair. However, the extent of intestinal
      malperfusion is difficult to assess since clinical signs typically present
      late: 75% of patients have no clinical evidence at presentation, as in our
      patient. This can delay diagnosis and management contributing to the high
      mortality. The use of biomarkers such as serum lactate has been suggested
      as potentially useful indicators of mesenteric ischaemia.4 5 If the
      initial lactate level is high with no other cause and radiological or
      clinical evidence of bowel ischaemia is present, revascularisation using
      percutaneous endovascular techniques should be performed first to
      alleviate intestinal ischaemia, followed by serial measurements of lactate
      level to look for improvement in peripheral perfusion.3 If the lactate
      level is persistently high, surgical revascularisation must be considered.
    Our patient had no clinical or biochemical signs
      suggestive of bowel ischaemia. Therefore, interpositional ascending aortic
      grafting was performed first, since proximal extension of the dissection
      would be dangerous and entry site closure may improve blood flow along the
      SMA. The left lower limb pulses reappeared after surgery. However, CT did
      not show similar improvement in the SMA; on the contrary, the jejunum
      showed decreased enhancement. Superior mesenteric artery revascularisation
      was indicated. An anterograde approach was adopted for endovascular
      stenting of the SMA orifice, followed by open fenestration and closure
      with vein patch distally. No bowel resection was required. The successful
      outcome in this patient demonstrates good treatment prioritisation, prompt
      decision making, and multidisciplinary cooperation in the management of
      type A aortic dissection with peripheral malperfusion.
    Author contributions
    The authors have made substantial contributions to
      the concept or design of this study, acquisition of data, analysis or
      interpretation of data, drafting of the article, and critical revision for
      important intellectual content. The authors had full access to the data,
      contributed to the study, approved the final version for publication, and
      takes responsibility for its accuracy and integrity.
    Conflicts of interest
    The authors have disclosed no conflicts of
      interest.
    Funding/support
    This research received no specific grant from any
      funding agency in the public, commercial, or not-for-profit sectors.
    Ethics approval
    The patient was treated in accordance with the
      Declaration of Helsinki. The patient provided informed consent for all
      procedures.
    References
    1. Okita Y, Takamoto S, Ando M, Morota T,
      Kawashima Y. Surgical strategies in managing organ malperfusion as a
      complication of aortic dissection. Eur J Cardiothorac Surg 1995;9:242-6. Crossref
    2. Girardi LN, Krieger KH, Lee LY, Mack CA,
      Tortolani AJ, Isom OW. Management strategies for type A dissection
      complicated by peripheral vascular malperfusion. Ann Thorac Surg
      2004;77:1309-14. Crossref
    3. Slonim SM, Nyman U, Semba CP, Miller DC,
      Mitchell RS, Dake MD. Aortic dissection: percutaneous management of
      ischemic complications with endovascular stents and balloon fenestration.
      J Vasc Surg 1996;23:241-51. Crossref
    4. Muraki S, Fukada J, Morishita K,
      Kawaharada N, Abe T. Acute type A aortic dissection with intestinal
      ischemia predicted by serum lactate elevation. Ann Thorac Cardiovasc Surg
      2003;9:79-80.
    5. Murray MJ, Gonze MD, Nowak LR, Cobb CF.
      Serum D(-)-lactate levels as an aid to diagnosing acute intestinal
      ischemia. Am J Surg 1994;167:575-8. Crossref

