Thoraco-abdominal Aorta Revascularization through a Retroperitoneal Approach

Yue-hong Zheng ＊,Kun Yu ,Jie-feng Zhang ＊,Nim Choi ,Hong-ru Deng ,and Furtado Rui

1Department of Vascular Surgery,Peking Union Medical College Hospital,Chinese Academy of Medical Sciences &Peking Union Medical College,Beijing 100730,China

2Department of Extracorporeal Circulation,Fuwai Hospital,Beijing 100037,China

3Department of Vascular Surgery,Weifang People’s Hospital,Shandong 261041,China

4Department of General Surgery,Cir Gen/Vas,Central Hospital Centre S.Januario,Macau,China

THE transperitoneal approach to the aorta is the most widely accepted in aortic surgery as it is simple,fast,and provides excellent exposure of the aneurysm.1In recent years,there has been an increasing interest in the retroperitoneal approach to the aorta,which was associated with a significantly lower rate of complications,rapid recovery of gastrointestinal functions,and less perioperative blood loss.In the present study,we evaluated the clinical outcome of retroperitoneal approach in aorta repair for aortic lesions in 7 patients to assess the application of that approach in clinal practice.

PATIENTS AND TREATMENTS

The 7 cases presented with aortic diseases in Macau Central Hospital Centre S.Januario from June 2007 to May 2008.All cases are male,with history of hypertension,and 4 of them presented with coronary heart disease(Table 1).

For abdominal aortic aneurysm,the exposure of the aorta was achieved through a left retroperitoneal access.The incision was made along the lateral border of the rectus abdominis to the costal margin,and the abdominal organs were pushed aside to expose the perirenal aorta,renal arteries,iliac arteries,and bilateral ureters.For suprarenal aneurysm,the 12th rib was removed to fully expose the surgical field.

For complex thoracoabdominal aortic dissection,the skin incision was made at the fifth intercostal space,extending downward along the paramedian abdominal line after crossing the costal margin and ending at the level of the pubis.Once the costal margin was interrupted,the left hemidiaphragm was circumferentially incised along its parietal insertion.The peritoneal sac was then detached from the abdominal wall;the abdominal viscera were moved to the right,and the thoracoabdominal aorta was thereby completely exposed.

Table 1.Demographic information and surgical treatment of 7 cases of aortic diseases

Case one.The diameter of aortic aneurysm in this case was measured as 55 mm at thoracic segment and 60 mm at abdominal segment.The patient was treated with Crawford procedure.The entire range of thoracic and abdominal aorta was exposed through a retroperitoneal entry after making a thoracoabdominal incison.The aneurysm was clamped just proximal to the anticipated proximal anastomosis.A Y-shaped 20-mm graft (Boston Scientific,Natick,MA,USA) was anastomosed end-to-end with the aorta.The origins of the celiac trunk,superior mesenteric artery,and right renal artery were reconstructed by anastomosing the orifices in a single button to the side of the graft.In addition,the left renal artery was anastomosed with the lateral wall of the artificial artery and the bilateral iliac arteries were jointed with the bifurcation.

Case two.For that patient with suprarenal aortic aneurysm,left retroperitoneal access was employed to expose the perirenal aorta,bilateral renal arteries,bilateral iliac arteries,and bilateral ureters.The intermittent perfusion of left renal artery was achieved by a coronary perfusion octpus plug (Boston Scientific).A Gore-Tex 16-8mm branched graft (W.L.Gore &Associates,Inc.,Flagstaff,AZ,USA) was utilized to construct the abdominal aorta.

Case three.That case of aortic pseudoaneurysm was treated by replacing abdominal aorta with 18-mm straight plastic vessel (Boston Scientific).An oblique incision at lower lumber was made to allow full exposure.Existence of inflammatory adhesion imposed difficulty on dissection of the aorta.

Case four and case five.A patient with main iliac occlusion was treated with aotic-right iliac artery bypass graftviaright retroperitoneal approach.A similar case received the operation conducted in the same way on the left side.

Case six and case seven.Hybrid technique was applied in 2 cases of infrarenal abdominal aortic aneurysm that involved the bilateral internal iliac arteries to reestablish perfusion.A curved incision was made at the right lateral abdomen for adequate exposure of the aneurysm.A bridge was constructed between internal and external iliac arteries with an 8-mm artificial vessel (Boston Scientific),and a Zenith bifurcated stent (Cook Group,Bloomington,IN,USA) was delivered simultaneously into the abdominal aorta.

RESULTS

There was no operative or postoperative death in the 7 cases.No perioperative intestinal adhesion or ureteral obstruction was found.Follow-up was fulfilled in all the cases with the mean duration of 18.6±11.3 months (range,16.7-24.2 months).No aorta-related mortality was observed during follow-up.

Case one presented postoperative delayed paraplegia.The sensation and movement of his lower limb were both normal the day after the operation.But the muscle strength of both legs turned out to be measured at grade 1 on the morning of the first postoperative day after one episode of hypotension at night.The tactile sensation of the foot remained,but the pain and fine tactile sensation was lost.A week later,necrosis occurred in the skin and subcutaneous layer of abdominal wall right to the incision,which was cured after the skin grafting.This patient was able to walk with crutch after 3 month of rehabilitation training.

DISCUSSION

Selection of an appropriate approach to allow the needed arterial exposure,careful dissection of the pararenal and paravisceral aorta,and adherence to the proper sequence of clamping and unclamping of the aorta and visceral branches is crucial for the success of an aortic operation.Exposure of the abdominal aorta through the left retroperitoneum is a well-accepted technique.1,2The principal components of this approach originally emphasized by Crawford focus on operative simplicity and expediency,minimal dissection,and avoidance of heparin administration or extracorporeal bypass.3Compared with the conventional laparotomy,the retroperitoneal entry decreases the intestinal adhesion,exposure of the viscera,and postoperative loss of body fluid.

Prolonged respiratory assistance and positive end expiratory pressure ventilation were required in case one due to postoperative pulmonary insufficiency.This complication was attributed to intraoperative pulmonary handling,unilateral lung ventilation,and injury caused by cardiopulmonary bypass.4,5End organ protection could be achieved by profound hypothermia and subsection circulatory arrest during operation for thoracoabdominal aortic aneurysm,which has been proved highly effective for the avoidance of central neurological deficits.6Spinal and visceral protection was ensured by profound hypothermia during circulatory interruption and early resumption of perfusion in case one.With a staged descending aorta occlusion technique,the ischemic time of spinal cord and viscera could be reduced.7,8

Injury to the spinal cord is one of the most serious complications in patients undergoing thoracoabdominal aorta replacement,but the cause of paraplegia in case one is not clear.It might be the result of spinal cord ischemia during lower body circulatory arrest,perioperative hypotension,embolism in intercostal arteries,occlusion of critical intercostal arteries by the graft,sacrifice of lumbar arteries that do not directly supply spinal cord but augment collateral blood flow,or several factors in combination.9

The necrosis of abdominal wall in case one was a rare vascular complication of surgery.It might be related with the occlusion of lumber arteries,extensive dissociation of the posterior peritoneum,and excessive hemostasis.This complication is suspected to be idiopathic in the retroperitoneal route.

In recent years,hybrid surgical procedures for the treatment of abdominal aortic aneurysms offer an attractive and encouraging alternative to open repair for their potential benefits,such as avoiding thoracotomy and supraceliac cross-clamping.In those procedures,the retroperitoneal approach provides an optimal access to reestablish the right renal artery and right aortoiliac artery,and allows visualization of the right internal iliac artery.10,11

In conclusion,the retroperitoneal entry could be applied to thoracoabdominal aorta replacement,supra-and infrarenal abdominal aorta replacement,aortoiliac reconstruction,and renal artery reconstruction.

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