Inflammatory abdominal aortic aneurysm: A postoperative course of retroperitoneal fibrosis

PURPOSE: The long-term outcome and the development of retroperitoneal fibrosis after surgery on an inflammatory aortic aneurysm was studied. METHODS: Between 1989 and 1997, 1035 patients underwent surgery for an abdominal aneurysm, 42 of whom (4.1%) had typical signs of inflammation. All patients underwent computed tomography (CT) scans before operation, and 26 patients were followed up with a CT scan after a median of 36 months (range, 10 to 91 months). RESULTS: The inflammatory layer resolved completely in only 23% of the patients. One patient had marked progression, 35% of patients showed improvement, and the remaining patients had no change, compared with the preoperative findings. Although clinical symptoms subsided in 90% of patients, in five cases an involvement of the ureter or intestine that did not exist at the time of operation developed. Although ureteral involvement to the inflammation tends to subside after surgery, persisting fibrosis was associated with ureteral entrapment in 30% of these cases and resulted in renal compromise in 49%. Hydronephrosis that was not present at the time of operation was found in 19% of patients, despite improving or stable inflammatory lesions. CONCLUSION: This case-control study supports the findings that retroperitoneal fibrosis persists longer than previously thought, and progression might even occur. Formerly uninvolved organs might become included in the process despite regression of the layer, leading to considerable problems if the condition is not treated in institutions familiar with this complex disease. We advocate a moderated follow-up scheme, as in the case of ordinary abdominal aortic aneurysm, and the need for long-term surveillance of inflammatory aneurysms.     

Descending or Thoracoabdominal Aortic Aneurysm Repair Without Intercostal Vessel Reconstruction Using Contrast Magnetic Resonance Angiography: Report of Two Cases

Two high-risk patients underwent a graft replacement for descending thoracic or thoracoabdominal aortic aneurysms without the reconstruction of any intercostal and lumbar arteries. The first patient was an 81-year-old woman with asthma and renal dysfunction who was diagnosed to have a descending thoracic aortic aneurysm extending from the Th8 to Th12 level. Contrast magnetic resonance angiography (MRA) demonstrated the Adamkiewicz artery to originate from the left second lumbar artery. The second patient was a 59-year-old man with left ventricular dysfunction due to aortic and mitral stenoses who was diagnosed to have a Crawford type IV thoracoabdominal aortic aneurysm. Contrast MRA showed the Adamkiewicz artery to originate from the left ninth intercostal artery. In general, the reestablishment of the spinal cord's blood supply, whenever possible, is generally considered to be necessary in such patients to prevent spinal cord injury. However, the reimplantation of intercostal vessels is the most complex aspect of this surgical modality, and therefore, it may cause a substantial increase in the cardiopulmonary bypass time. However, at least in some cases, such as the two cases presented herein, the use of contrast MRA was found to reduce the risk in surgery for descending thoracic or thoracoabdominal aortic aneurysms by eliminating the need for any intraoperative management of the intercostal and lumbar arteries. Received: April 6, 2001 / Accepted: September 11, 2001     

Hybrid procedures as a combined endovascular and open approach for pararenal and thoracoabdominal aortic pathologies

OBJECTIVES: to report our experience with hybrid vascular procedures in patients with pararenal and thoracoabdominal aortic pathologies. METHODS: 68 patients were treated for thoracoabdominal aortic pathologies between October 1999 and February 2004; 19 patients (16 men; mean age 68, range 40-79) with high risk for open thoracoabdominal repair were considered to be candidates for combined endovascular and open repair. Aortic pathologies included five thoracoabdominal Crawford I aneurysms, one postdissection expanding aneurysm, three symptomatic plaque ruptures (Crawford IV), five combined thoracic descending and infrarenal aneurysms with a healthy visceral segment, three juxtarenal or para-anastomotic aneurysms, and two patients with simultaneous open aortic arch replacement and a rendezvous maneuver for thoracic endografting. Commercially available endografts were implanted with standardized endovascular techniques after revascularization of visceral and renal arteries. RESULTS: Technical success was 95%. One patient developed a proximal type I endoleak after chronic expanding type B dissection and currently is waiting conversion. Nine patients underwent elective, five emergency and five urgent (within 24 h) repair. 17 operations were performed simultaneously, and 2 as a staged procedure. Postoperative complications include two retroperitoneal hemorrhages, and one patient required long-term ventilation with preexisting subglottic tracheal stenosis. Thirty-day mortality was 17% (one multiple organ failure, one secondary rupture after open aortic arch repair, one myocardial infarction). Paraplegia or acute renal failure were not observed. Total survival rate was to 83% with a mean follow-up of 30 months. CONCLUSIONS: Midterm results of combined endovascular and open procedures in the thoracoabdominal aorta are encouraging in selected high risk patients. Staged interventions may reduce morbidity.     

Surgical repair of aneurysms involving the suprarenal, visceral, and lower thoracic aortic segments: early results and late outcome

OBJECTIVE: The purpose of this study is to review our experience with surgical repair of lower thoracoabdominal and suprarenal aortic aneurysms to determine early and late survival rates and identify factors influencing morbidity and survival among these patients. MATERIALS: From 1989 through 1998, 165 consecutive patients underwent repair of 108 thoracoabdominal (55 group III and 53 group IV) and 57 suprarenal aneurysms. The study group consisted of 109 men and 56 women with a mean age of 70 years (median, 70 years; range, 29-89 years). Mean aneurysm diameter was 6.9 cm (median, 6.5 cm; range, 4-12 cm). There were 125 aneurysms (76%) repaired electively; 40 repairs (24%) were nonelective. The cause of 12 aneurysms (7%) was chronic aortic dissection; the remaining 153 (93%) were degenerative aneurysms. RESULTS: The early postoperative (30-day) mortality rates were 7% (9/125) for elective and 23% (9/40) for nonelective operations (P =.016). For both elective and urgent procedures, early mortality was 1.8% (1/57) for suprarenal aneurysm repair, 11% (6/53) for group IV thoracoabdominal aneurysms, and 20% (11/55) for group III thoracoabdominal aneurysms (P =.013, suprarenal vs group III). Spinal cord ischemia occurred after 6% (10/165) of aneurysm repairs (4% paraplegia, 2% paraparesis). None of the 57 suprarenal aneurysm repairs were complicated by spinal cord ischemia, whereas it occurred in 2% (1/53) of group IV thoracoabdominal aneurysms and 16% (9/55) of group III thoracoabdominal aneurysms (P =.001, suprarenal vs group III; P =. 016, group IV vs group III). Three (25%) of the 12 patients with dissection developed spinal cord ischemia; this compared with seven (5%) of 153 patients with degenerative aneurysms (P =.027). The cumulative 3-year survival rate for the entire series was 71% (95% CI, 64%-79%), and 5-year survival was 50% (95% CI, 40%-60%). CONCLUSIONS: Aneurysms involving the suprarenal, visceral, and lower thoracic aorta may be repaired with acceptable perioperative mortality and late survival rates. The risk of spinal cord ischemia is increased for patients with aortic dissection and may be stratified according to the proximal extent of the aneurysm.     

Surgery of thoracoabdominal aneurysms

Seventeen patients with thoracoabdominal aneurysms, including 5 ruptured aneurysms, were operated upon using a left diaphragm-splitting thoracoabdominal incision and the retroperitoneal route. A temporary shunt was used in 13 patients, femorofemoral perfusion in 1 and cold perfusion cooling of the kidneys in 3 patients. The step-by-step reattachment technique into ready-made limbs or holes in the Dacron graft ensured that visceral and renal ischaemic times remained within acceptable limits. The mean renal and proximal clamping times were 44 and 77 min, respectively. One patient with a ruptured aneurysm (6%) died of diffuse bleeding. The others recovered without paraplegic, renal or other severe complications. During the follow-up period, mean 44 months and range 10-116 months, 3 patients died of lung cancer and 2 of coronary disease giving a late mortality of 29%. The remaining 11 patients are alive and well. The cumulative 2- and 5-year survival is 87% and 62% respectively. The patency rate of the grafts was 100% and that of the 30 individually revascularised arteries 80%. We recommend elective surgery for thoracoabdominal aneurysms using a temporary shunt or cold perfusion cooling of the kidneys as a protective measure against perioperative ischaemia.     

Combined endovascular and surgical approach (hybrid treatment) for management of type IV thoracoabdominal aneurysm

The purpose of this article is to report successful hybrid treatment of a sovraprosthetis type IV thoracoabdominal aneurysm. This technique was used in a 65-year-old man with chronic rupture of a type IV thoracoabdominal aneurysm not suitable for aortic cross-clamping because of a severe cardiopathy (left ventricular ejection fraction 20%); the patient underwent previous repairs of aortic arch and infrarenal abdominal aortic aneurysms. Perioperative complications were absent. Postoperative day 21 computed tomography and monthly duplex ultrasonography confirmed the complete exclusion of the aneurysm with proper perfusion of visceral vessels. At the seventh postoperative month, the patient died of a massive recurrence of myocardial infarction. Hybrid treatment for thoracoabdominal aneurysms may represent a valid solution for those patients with poor cardiac and respiratory reserve, reducing cardiac stress and the duration of visceral ischemia, which are still the main causes of morbidity and mortality for this type of intervention.     

The accuracy of computed tomography in the diagnosis of retroperitoneal blood in the presence of abdominal aortic aneurysm

The use of computed tomography (CT) in the management of patients who are hemodynamically stable with symptoms suggestive of ruptured abdominal aortic aneurysm and in hemodynamically unstable patients without palpable or known aortic aneurysms was analyzed in a retrospective study. One hundred forty-two CT scans were performed; 48 patients had abdominal aortic aneurysms and 35 had no evidence of rupture or retroperitoneal blood. Ten patients had CT scans that showed evidence of rupture, and three patients had CT scans that were thought to be indeterminate for rupture, probably inflammatory. Forty patients underwent laparotomy. Excluding the three patients with inflammatory aneurysms, the results of CT scanning were compared with the findings at laparotomy. The sensitivity of CT scanning for the diagnosis of retroperitoneal blood in the presence of abdominal aortic aneurysm was 77% and the specificity was 100%, with an overall accuracy of 92%. An algorithm for the management of the patient with symptoms suggestive of a ruptured aneurysm is presented.     

Shunting of the Coeliac and Superior Mesenteric Arteries during Thoracoabdominal Aneurysm Repair

OBJECTIVES: To describe our experience with shunting of the coeliac and superior mesenteric arteries during thoracoabdominal aneurysm repair. DESIGN: Retrospective study. MATERIAL: Eight patients undergoing resection and graft replacement of Crawford type III (5) and type IV (3) thoracoabdominal aortic aneurysms were included in this series. One patient had rupture, four were symptomatic and three were operated on electively. METHODS: A vascular graft with a sidearm was applied for the reconstructions. A T-shunt was connected to the sidearm. Following completion of the proximal anastomosis the shunt was inserted into the coeliac and superior mesenteric arteries. The anastomoses to these arteries and the renal arteries were then completed. Finally the distal anastomosis was performed. RESULTS: There was no early mortality (30 days). One patient had postoperative paraparesis, but recovered quite well. Reoperation became necessary due to sigmoid necrosis in one patient and due to haemorrhage in another. During the follow-up period four patients died but the other patients are alive between 3 and 8 years after surgery. CONCLUSION: The application of shunting of the superior mesenteric and coeliac arteries during thoracoabdominal aortic surgery is feasible and the results have been acceptable. Further investigation of the optimal blood flow needed to avoid intestinal ischaemia in a larger series of patients is desirable.     

A Ruptured Pancreaticoduodenal Artery Aneurysm Associated with a Splenic Artery Aneurysm: Report of a Case

True pancreaticoduodenal artery (PDA) aneurysms are extremely rare. We report herein a case of a ruptured PDA aneurysm associated with a nonruptured splenic artery aneurysm which was successfully treated by surgery. A 55-year-old man was admitted to a local hospital complaining of sudden abdominal and back pain, and thereafter he was transferred to our university hospital. Abdominal computed tomography revealed retroperitoneal hematoma and an enhanced round spot suggesting a peripancreatic aneurysm. Emergency angiography showed a 20-mm-sized aneurysm in the inferior PDA and a 10-mm-sized aneurysm in the splenic artery. The patient underwent an emergency laparotomy with a diagnosis of a ruptured PDA aneurysm. After evacuating a large volume clot in the right retroperitoneal space and the peritoneal cavity, we detected an index finger-sized aneurysm with arterial bleeding in the right inferioposterior aspect of the pancreas. Hemostasis was obtained by oversewing the aneurysm and a ligation of the feeding arteries. A prophylactic splenectomy was performed for the nonruptured splenic artery aneurysm. This case indicates that emergency angiography is indispensable for both a definitive diagnosis and adequate surgical treatment of PDA aneurysms. Received: July 19, 2000 / Accepted: January 9, 2001     

Inflammatory abdominal aortic aneurysms: a thirty-year review

The operative records of 2816 patients undergoing repair for abdominal aortic aneurysm (AAA) from 1955 to 1985 were reviewed. Inflammatory aortic or iliac aneurysms were present in 127 patients (4.5%), 123 men and four women. Most patients were heavy smokers (92.1%). Clinical evidence of peripheral arterial occlusive disease and coronary artery disease was found in 26.6% and 39.4%, respectively. Additional aneurysms occurred in half of the patients; iliac aneurysms were the most common (55 patients), followed by thoracic or thoracoabdominal (17 patients), femoral (16 patients), and popliteal aneurysms (10 patients). Ultrasound and computed tomography suggested the diagnosis in 13.5% and 50%, respectively; angiography was not helpful. Excretory urographic findings of medial ureteral displacement or obstruction suggested the diagnosis in 31.4%. The aneurysm was repaired in 126 patients. Only one patient experienced acute aneurysm rupture, but eight patients had chronic contained leakage. When compared with patients who have ordinary atherosclerotic aneurysms, patients with inflammatory aneurysms are significantly more likely to have an elevated erythrocyte sedimentation rate (ESR, 73% vs. 33%, p less than 0.0001); weight loss (20.5% vs. 10%, p less than 0.05); symptoms (66% vs. 20%, p less than 0.0001); and an increased operative mortality rate (7.9% vs. 2.4%, p less than 0.002). The triad of chronic abdominal pain, weight loss, and elevated ESR in a patient with an abdominal aortic aneurysm is highly suggestive of an inflammatory aneurysm and may be beneficial in the preoperative preparation of the patient for aneurysm repair.     

A Strategy for Treatment of Type III and IV Thoracoabdominal Aortic Aneurysm

The aim of this study was to describe the results of resection and graft replacement for type III and IV thoracoabdominal aortic aneurysm repair. In this retrospective study, 27 patients underwent resection and graft replacement for type III (10) or type IV (17) thoracoabdominal aortic aneurysms. Nine patients had rupture, 12 were symptomatic, and 6 were operated on electively. The clamp-and-sew technique was applied in six cases. In 12 patients with type IV aneurysm the proximal part of the vascular graft was beveled, including the orifices of the celiac, superior mesenteric, and one or both renal arteries in the proximal anastomosis. Finally, eight patients underwent surgical application of a shunt for perfusion of the celiac and superior mesenteric arteries. One patient was treated with a combination of open and endovascular surgery. There were four early deaths (14.8%), all following operations for rupture, which represents a 45% mortality rate in this subgroup of patients. Two patients with type III aneurysm had postoperative paraparesis. One was symptomatic whereas the other was operated on electively. Excluding the patients with rupture, the accumulated 5-year survival rate was 65%. These results indicate that direct cross-clamping of the aorta gives limited time for performing the necessary anastomoses without inducing mesenteric ischemia. Inclusion of the orifices of the visceral arteries in the upper anastomosis is a feasible method during surgery for type IV aneurysms. Finally, shunting of the celiac and the superior mesenteric arteries seems to be useful, especially during surgery for type III aneurysms.     

Thoracoabdominal Aortic Aneurysm Repair in Cardiac Transplant Recipients

We present here two cases of asymptomatic thoracoabdominal aortic aneurysms that were successfully operated on in heart transplant patients 8 and 23 months after transplantation. Thoracoabdominal aortic aneurysm was present prior to transplantation in one patient. In the other patient only the abdominal aortic aneurysm was found before transplantation. Indications for transplantation were ischemic and valvular cardiomyopathy. Surgical aortic aneurysm repair was performed with the standard technique. Both patients were discharged from the hospital. The possible contributing factors to the development and enlargement of aortic aneurysms and perioperative assessment are also discussed. Radiologic surveillance is warranted in any heart transplant recipient with abdominal or thoracoabdominal aortic aneurysms because of the more rapid aneurysm expansion.     

Type IV thoracoabdominal aortic aneurysm with lymphoplasmacytic aortitis and cystic medial degeneration in a 32-year-old patient with Marfan syndrome

Aortitis identified in approximately 12% of all thoracoabdominal aneurysms. The most common subtype of inflammatory aortitis is giant cell aortitis, followed by lymphoplasmacytic aortitis. Inflammatory aortitis may occur in isolation or as part of a systemic inflammatory disorder such as Takayasu arteritis, systemic lupus erythematosus, rheumatoid arthritis, and giant cell arteritis. Aortitis has not been described in patients with Marfan syndrome. We report the case of a 32-year-old man with Marfan syndrome and a strong family history of aneurysmal disease who presented with an asymptomatic Crawford type IV thoracoabdominal aneurysm. His aneurysm had no associated dissection, and surgical pathology revealed severe medial degeneration and lymphoplasmacytic aortitis. To our knowledge, this is the first report of such a finding in a patient with Marfan syndrome.     

Exclusion-bypass for aneurysms of the descending thoracic and thoracoabdominal aorta

From October 1973 to April 1985, 81 patients with aneurysms of the descending thoracic or thoracoabdominal aorta underwent surgery. Eight (10%) of these patients were treated by exclusion-bypass. The aneurysm was located in the descending aorta alone in five cases, and in the descending thoracic and thoracoabdominal aorta in three cases. In all cases, the proximal anastomosis of the bypass was performed on the ascending aorta. The site of the distal anastomosis was the supraceliac aorta in two cases, the infrarenal aorta in three cases and the iliac arteries in three other cases. Exclusion was bipolar, at each end of the aneurysm, in six cases, and unipolar, ie. proximal interruption only, in two cases. Two patients died during the first postoperative month, one of rupture of the distal portion of the aortic arch, the second, after onset of secondary paraplegia. There were no other spinal, cardiac or cerebral complications. One patient died three months postoperatively of intercurrent pulmonary infection. The five other surviving patients whose mean follow-up period is 48.1±25 months, are alive and enjoying good health. Resection and grafting as advocated by Crawford, is the usual treatment proposed for aneurysms of the descending thoracic and thoracoabdominal aorta. Exclusionbypass may however be preferred in the following cases: elderly patients with compromised respiratory status, aneurysms of the descending thoracic aorta, either voluminous, of infectious origin or associated with aneurysm of the infrarenal abdominal aorta.     

Staged endourologic and endovascular repair of an infrarenal inflammatory abdominal aortic aneurysm presenting with forniceal rupture

We present the case of a 79-year-old female who presented with severe left flank pain and a pulsatile abdominal mass. She was diagnosed with left peripelvic urinary extravasation and forniceal rupture secondary to an intact infrarenal inflammatory abdominal aortic aneurysm with extensive periaortic fibrosis. Successful operative repair was performed with staged ureteral and endovascular stenting with subsequent resolution of periaortic inflammation and ureteral obstruction, and shrinkage of the aneurysm sac. Inflammatory abdominal aortic aneurysms (IAAAs) represent 5% to 10% of all abdominal aortic aneurysms. The distinguishing features of inflammatory aneurysms include thickening of aneurysm wall, retroperitoneal fibrosis, and adhesions to adjacent retroperitoneal structures. The most commonly involved adjacent structures are the duodenum, left renal vein, and ureter. Adhesions to the urinary system can cause hydronephrosis or hydroureter and result in obstructive uropathy. An unusual case of IAAA presenting with forniceal rupture is presented, with successful endovascular and endourologic repair.     

Rupture of a Previously Thrombosed Thoracoabdominal Aneurysm

Spontaneous thrombosis of abdominal aortic aneurysms is rare. A patient with a 12-cm thoracoabdominal aneurysm developed sudden thrombosis of his aneurysm. He was treated with axillobifemoral bypass. He went on to rupture 7 months later. While spontaneous thromboses of abdominal aortic aneurysms have been previously reported, we did not find any reports of a thrombosed thoracoabdominal aneurysm or a subsequent rupture of this type of aneurysm. The literature on thrombosis of aneurysms is reviewed as well as proposed etiologies for thrombosis and subsequent rupture. We believe that resectional therapy may be warranted even in high-risk patients.     

Endovascular stent-graft repair of pararenal and type IV thoracoabdominal aortic aneurysms with adjunctive visceral reconstruction

OBJECTIVE: Pararenal and type IV thoracoabdominal aortic aneurysms (TAAA) are not currently considered as indications for endovascular repair given unfavorable neck anatomy or aneurysm involvement of the visceral vessels. Open repair of these aneurysms is associated with significant morbidity and mortality, particularly postoperative renal dysfunction. In selective high-risk patients, debranching of the visceral aorta to improve the proximal neck region can be used to facilitate endovascular exclusion of the aneurysm. METHODS: Between October 2000 and July 2003, 10 patients were treated with open visceral revascularization and endovascular repair of pararenal and type IV TAAAs at a single institution. Patient demographics and procedural characteristics were obtained from medical records. RESULTS: Overall 13 visceral bypasses were performed in 10 patients: 6 patients with a single iliorenal bypass, 3 with a hepatorenal bypass, and 1 patient with complete visceral revascularization. Juxtarenal aneurysms occurred in 5 patients (50%), suprarenal aneurysms in 3 patients (30%), and type IV TAAAs in 2 patients (20%). All patients had successful endovascular aneurysm exclusion. Mean follow-up was 8.7 months. There were no perioperative deaths, neurologic deficits coagulopathies, or renal dysfunction. Follow-up spiral computed tomography scans demonstrated patency of all bypass grafts with only one patient requiring a secondary intervention for late type I leak which was sealed with placement of a proximal cuff. CONCLUSION: These initial results suggest that are similar to infrarenal AAA endovascular repair. This combined approach to repair of pararenal and type IV TAAAs reduces the morbidity and mortality of open repair, and represents an attractive option in high-risk patients while endoluminal technology continues to evolve.     

Inflammatory aneurysm of the infrarenal aorta

Abdominal aneurysms with extensive periarortic fibrosis should be considered a variant of idiopathic retroperitoneal fibrosis. Rupture of these inflammatory aortic aneurysms seems to be less frequent than in arteriosclerotic aneurysms. Due to this experience preoperative corticosteroid treatment may be allowed, which appeared effective in patients with retroperitoneal fibrosis. 5 cases of inflammatory aneurysms are presented.     

A new predictive model for adverse outcomes after elective thoracoabdominal aortic aneurysm repair

BACKGROUND: Recent recommendations have emphasized individualized treatment based on balancing a patient's risk of thoracoabdominal aortic aneurysm rupture with the risk of an adverse outcome after surgical repair. The purpose of this study was to determine which preoperative risk factors currently predict an adverse outcome after elective thoracoabdominal aortic aneurysm repair. METHODS: A single, composite end point termed adverse outcome was defined as the occurrence of any of the following: death within 30 days, death before discharge from the hospital, paraplegia, paraparesis, stroke, or acute renal failure requiring dialysis. A risk factor analysis was performed using data from 1,108 consecutive elective thoracoabdominal aortic aneurysm repairs. RESULTS: The incidence of an adverse outcome was 13.0% (144 of 1,108 patients); predictors included preoperative renal insufficiency (p = 0.0001), increasing age (p = 0.0035), symptomatic aneurysms (p = 0.020), and extent II aneurysms (p = 0.0001). These risk factors were used to construct an equation that estimates the probability of an adverse outcome for an individual patient. CONCLUSIONS: This new predictive model may assist in decisions regarding elective thoracoabdominal aortic aneurysm operations. For patients who are acceptable candidates, contemporary surgical management provides favorable results.     

Retroperitoneal approach in the treatment of supra- and infrarenal aortic aneurysms

The retroperitoneal approach for the treatment of thoracoabdominal type IV and infrarenal aortic aneurysms is an accepted alternative to thoraco-phrenolaparotomy. The purpose of this retrospective study was to report our experience and results in terms of respiratory and renal complications. From January 1997 to December 2003, 48 patients (36 with thoracoabdominal type IV and 12 with infrarenal aortic aneurysms) were treated by a retroperitoneal extrapleural approach in intercostal space X or XI. We performed 40 aorto-aortic and 8 aorto-basilar reconstructions. The perioperative mortality was 2%. Postoperative respiratory insufficiency was 8%, and postoperative renal insufficiency 12%. Permanent dialysis was necessary in 4% of cases. The survival rates were 98%, 89.4% and 58.7 at 1, 5 and 7 years, respectively. Retroperitoneal extrapleural access with a partial phrenotomy results in a significantly reduced incidence of postoperative respiratory complications.