The impact of diaphragm management on prolonged ventilator support after thoracoabdominal aortic repair

Temporary diaphragm pacing for patients at risk of prolonged mechanical ventilation after extensive aortic repair

Objective

Prolonged mechanical ventilation (MV) after extensive aortic reconstructive surgery is common. Studies have demonstrated that diaphragm pacing (DP) improves lung function in patients with unilateral diaphragm paralysis. The goal of this study is to determine whether this technology can be applied to complex aortic repair to reduce prolonged MV and other respiratory sequelae.

Methods

A retrospective review was performed of patients who underwent temporary DP after extensive aortic reconstructive surgery between 2019 and 2022. The primary end point was prolonged MV incidence. Other measured end points included diaphragm electromyography improvement, length of hospitalization, duration of intensive care unit stay, and reintubation rates.

Results

Fourteen patients deemed at high risk of prolonged MV based on their smoking and respiratory history underwent DP after extensive aortic repair. The mean age was 70.2 years. The indications for aortic repair were a thoracoabdominal aortic aneurysm (n = 8, including 2 ruptured, 2 symptomatic, and 1 mycotic), a perivisceral aneurysm (n = 4), and a perivisceral coral reef aorta (n = 2). All patients had a significant smoking history (active or former) or other risk factors for ventilator-induced diaphragmatic dysfunction and prolonged MV. The mean total duration of MV postoperatively was 31.9 hours (range, 8.1-76.5 hours). The total average pacing duration was 4.4 days. Two patients required prolonged MV, with an average of 75.4 hours. Two patients required reintubation. No complications related to DP wire placement or removal occurred.

Conclusions

DP is safe and feasible for patients at high risk of pulmonary insufficiency after extensive aortic reconstructive surgery.

Open Treatments for Thoracoabdominal Aortic Aneurysm Repair

Thoracoabdominal aortic aneurysms (TAAA) represent a unique pathology that is associated with considerable mortality if untreated. While the advent of endovascular technologies has introduced new modalities for consideration, the mainstay of TAAA treatment remains open surgical repair. However, the optimal conduct of open TAAA repair requires careful consideration of patient risk factors and a collaborative team effort to mitigate the risk of perioperative complications. In this chapter, we briefly outline the history of treating TAAA, preoperative preparation and postoperative care, and our operative techniques for treatment.

Thoracoabdominal aortic aneurysm in connective tissue disorder patients

Connective tissue disorders (CTDs) are a group of genetically triggered diseases in which the primary defect involves collagen and elastin protein assembly with potential vascular degenerations such as thoracoabdominal aortic aneurysm (TAAA) and dissection. These most commonly include Marfan syndrome, Ehlers-Danlos syndrome, Loeys-Dietz syndrome, and familial thoracic aortic aneurysm and dissection. Open surgical repair represents the standard approach in this specific group of patients. Extensive aortic replacements are generally performed in order to reduce long-term complications caused by the progressive dilatation of the remnant aortic segments. In the last decades, endovascular interventions have emerged as a valid alternative in patients affected by degenerative TAAA. However, in patients with CTD, this approach presents higher rates of reinterventions and postoperative complications with a disputable long-term durability, and it is nowadays performed for very selective indications such as severe comorbidities and urgent/emergent settings. Despite a deeper knowledge of the pathophysiological mechanisms involved in CTD, improvements in medical therapy, and a multidisciplinary approach fully involved in the management of these usually frailer patients, this specific group still represents a challenge. Further dedicated studies addressing mid-term and long-term outcomes in this selected population are needed.

Open thoracoabdominal aortic aneurysm surgery technique: how we do it

More than four decades have passed since the modern principals to treat thoracoabdominal aortic aneurysm (TAAA) have been established. The historical challenges in repair of TAAA are represented by - and continue to be - multiorgan protection. Among all organs, the spinal cord remains one of the most vital and vulnerable. We described our current techniques of open extent II TAAA repair, including the following topics: anesthesia, intraoperative monitoring, skin incision, exposure of the TAAA, left heart bypass, graft replacement technique, intercostal artery reattachment, visceral/renal artery reconstructions, and postoperative care. We use cerebrospinal fluid drainage, distal aortic perfusion, mild passive hypothermia, sequential clamping, and visceral and renal perfusion using roller pump in all the cases for multiorgan protection. Both motor-evoked potentials and somatosensory-evoked potentials ere used to guide the conduct of intercostal artery reattachment. Our group demonstrated that the use of adjuncts has reduced the overall spinal cord ischemia rate after Extent I TAAA from 15% to less than 2% and after Extent II TAAA from 33% (50% with clamp time exceeding 40 minutes in "clamp and go" era) to less than 4%. The current standard practice of TAAA repair with adjuncts has improved outcomes, especially regarding spinal cord ischemia.

Diaphragm Preservation Reduces Respiratory Failure After Extent I Thoracoabdominal Aneurysm Repair

BACKGROUND

We sought to evaluate the impact of surgical approach (thoracophrenolaparotomy vs thoracotomy crura splitting) on the outcomes of extent I thoracoabdominal aortic aneurysm repair.

METHODS

Patient data were extracted from our aortic surgery database. The primary endpoint was need for tracheostomy, and secondary endpoints were operative mortality, myocardial infarction, stroke, spinal cord injury, de novo dialysis, and major adverse events (composite of secondary endpoints and tracheostomy). Freedom from death and reoperation during follow-up were calculated. Risk adjustment was obtained with propensity score matching and multivariable regression.

RESULTS

Three hundred twenty-five patients underwent extent I repair. Compared with thoracophrenolaparotomy patients (n = 226), thoracotomy crura-splitting patients (n = 99) had a higher rate of previous coronary revascularization (27.3% vs 14.2%, P = .005), valvular disease (64.6% vs 50.4%, P = .018), and chronic obstructive pulmonary disease (61.6% vs 28.3%, P = .000) and a lower forced expiratory volume in 1 second (46% vs 69%, P = .000). In a matched sample thoracotomy crura splitting was associated with a decreased need for tracheostomy (4.0% vs 13.1%, P = .035). The need for tracheostomy was predicted by female gender (odds ratio, 3.11; 95% confidence interval, 1.17-8.30; P = .023), forced expiratory volume in 1 second (odds ratio, 0.95; 95% confidence interval, 0.91-0.98; P = .003), and thoracophrenolaparotomy (odds ratio, 3.66; 95% confidence interval, 1.14-11.73; P = .029). Five-year freedom from mortality and reoperation were similar.

CONCLUSIONS

In patients undergoing extent I thoracoabdominal aortic aneurysm repair, thoracotomy crura splitting was associated with decreased need for tracheostomy.

Point of care diaphragm ultrasound in infants with bronchiolitis: A prospective study

BACKGROUND

Bronchiolitis is the most common reason for hospitalization of children worldwide. Many scoring systems have been developed to quantify respiratory distress and predict outcome, but none of them have been validated. We hypothesized that the ultrasound evaluation of the diaphragm could quantify respiratory distress and therefore we correlated the ultrasound diaphragm parameters with outcome.

METHODS

Prospective study of infants with bronchiolitis (1-12 months) evaluated in a pediatric emergency department. Ultrasonography examinations of the diaphragm was performed (diaphragm excursion [DE], inspiratory excursion [IS], inspiratory/expiratory relationship [I/E], and thickness at end-expiration [TEE] and at end-inspiration [TEI]; thickening fraction [TF]).

RESULTS

We evaluated 61 infants, 50.8 % males. Mean TF was 47% (IQR 28.6-64.7), mean I/E 0.47 (± 0.15), mean DE 10.39 ± 4 mm. There was a linear correlation between TF and oxygen saturation at first evaluation (P = 0.006, r = 0.392). All children with lower values of TF required HFNC and one of them required CPAP. A higher IS was associated with the future need of respiratory support during admission (P = 0.007). IS correlated with the hours of oxygen delivery needed (P = 0.032, r = 0.422). TEI (t = 3.701, P = 0.002) was found to be main predictor of hours of oxygen delivery needed.

CONCLUSION

This study described ultrasound diaphragmatic values of previously healthy infants with bronchiolitis. DE, IS, and TEI correlated with outcome. If confirmed in larger studies, bedside ultrasound semiology of the diaphragm can be a new objective tool for the evaluation and outcome prediction of infants with bronchiolitis.

Organ Protection During Thoracoabdominal Aortic Surgery: Rationale for a Multimodality Approach

Surgical repair of thoracoabdominal aortic aneurysms (TAAAs) remains a technically challenging operation that requires a systematic approach to prevent ischemic complications and achieve excellent clinical outcomes. Techniques for organ protection have evolved substantially over the past 20 years. This review describes our current multimodality approach to organ protection during TAAA repair.

Interpreting diaphragmatic movement with bedside imaging, review article

The diaphragm is the most important muscle of respiration. At equilibrium, the load imposed on the diaphragmatic muscles from transdiaphragmatic pressure balances the force generated by diaphragmatic muscles. However, procedural and nonprocedural thoracic and abdominal conditions may disrupt this equilibrium and impair diaphragmatic function. Diaphragmatic dysfunction is associated with respiratory insufficiency and poor outcome. Therefore, rapid diagnosis and early intervention may be useful. Ultrasound imaging provides quick and accurate bedside assessment of the diaphragm. Various imaging techniques have been suggested, using 2-dimensional and M-mode technology. Diaphragm viewing depends on the degree of robe movement, determined by the angle of incidence of the ultrasound beam and by the direction of probe movement. In this review, we will discuss the function of the diaphragm focusing on clinically important anatomical and physiological properties of the diaphragm. We will review the literature regarding various sonographic techniques for diaphragm assessment. We will also explore the evidence for the role of the tidal displacement of subdiaphragmatic organs as a surrogate for diaphragm movement.

Clinical outcomes of hybrid repair for thoracoabdominal aortic aneurysms

BACKGROUND

Thoracoabdominal aortic aneurysm (TAAA) hybrid repair consists of aortic visceral branch rerouting followed by TAAA endograft exclusion. This technique has been shown to represent a technically feasible strategy in selected patients.

METHODS

We analyzed 52 high-risk patients who underwent hybrid TAAA repair between 2001 and 2012 in our centre with a variety of visceral rerouting configurations and of commercially available thoracic endografts. Thirty-seven simultaneous (71.2%) and 15 staged procedures (21.8%) were performed with a four-vessel revascularization in 18 cases (34.6%), a three-vessel revascularization in 11 cases (21.2%) and a two-vessel revascularization in 23 cases (44.2%).

RESULTS

No intraoperative deaths were observed. We recorded a perioperative mortality rate of 13.5% (n=7), including deaths from multiorgan failure (n=2), myocardial infarction (n=2), coagulopathy (n=1), pancreatitis (n=1) and bowel infarction (n=1). Perioperative morbidity rate was 28.8% (n=15), including 2 cases of transient paraparesis and 1 case of permanent paraplegia. Renal failure (n=5), pancreatitis (n=3), respiratory failure (n=3) and dysphagia (n=1) were also observed. At median follow-up of 23.9 months procedure-related mortality rate was 9.6%: two patients died from visceral graft occlusion and three from aortic rupture. There were three endoleaks and one endograft migration, none of which resulted in death. Five patients (9.6%) died as a consequence of unrelated events.

CONCLUSIONS

Typical complications of conventional TAAA open surgery have not been eliminated by hybrid repair, and significant mortality and morbidity rates have been recorded. Fate of visceral bypasses and incidence of endoleak and other endograft-related complications needs to be carefully assessed. Hybrid TAAA repair should currently be limited to high-risk surgical patients with unfit anatomy for endovascular repair.

Novel use of a gastrointestinal stapler for diaphragm division during thoracoabdominal aortic exposure

A significant portion of the morbidity associated with a thoracoabdominal approach to the suprarenal aorta is due to postoperative pulmonary dysfunction. A contributing factor to this dysfunction is division of the diaphragm during surgical exposure and subsequent repair upon completion of the operation. In this brief technical report, we describe a novel technique using a gastrointestinal stapler to divide the diaphragm that is rapid, hemostatic, and aids with reapproximation at the completion of the case. This method of diaphragm division is quicker and less traumatic and has the potential to decrease the incidence of postoperative pulmonary dysfunction.

Early Results after Staged Hybrid Repair of Thoracoabdominal Aortic Aneurysms

BACKGROUND

The morbidity and mortality rates associated with open thoracoabdominal aortic aneurysm (TAAA) repair are substantial. This study was designed to review our early experience with the hybrid endovascular and, or open approach for TAAA repair.

STUDY DESIGN

Patients undergoing elective hybrid repair of their TAAAs were retrospectively reviewed.

RESULTS

Seventeen patients (mean age 69+/-15 years, male, 76%) underwent visceral and renal revascularization as the first stage of their hybrid repair. The Crawford extent included: II, 2; III, 8; and IV, 7. Perioperative mortality and complication rates after the first stage were 24% and 25%, respectively; the mean intensive care unit stay and total length of stay were 7+/-12 days (range 1 to 45 days) and 22+/-33 days (range 3 to 100 days), respectively. The endovascular aneurysm repair or second stage procedure was performed in 12 of 13 (92%) of the surviving patients, with a mean of 27+/-27 days (range 6 to 99 days) between the procedures. Two patients experienced intraoperative complications during the second stage, but there were no deaths or additional postoperative complications. Patients did not require the intensive care unit, and the overall mean length of stay after the second stage was 2+/-2 days (range 1 to 5 days). The mean postoperative followup among the 11 patients completing both stages was 8+/-12 months (range 1 to 15 months). The primary patency rate for the visceral and renal bypasses was 96% (54 of 56).

CONCLUSIONS

The hybrid approach for patients with TAAAs may reduce complications in the average, low-risk patient and may extend the indications for repair to patients considered higher risk based on age, comorbidities, or anatomic considerations.

Vocal cord paralysis after aortic arch surgery: Predictors and clinical outcome

OBJECTIVE

This study is retrospective cohort study of data on vocal cord paralysis after aortic arch surgery collected during 14 years at a general hospital. We investigated factors in the development of vocal cord paralysis after aortic arch surgery and the effect of vocal cord paralysis on clinical course and outcome.

METHODS

We reviewed data for 182 patients who underwent aortic arch surgery for aortic arch aneurysm and aortic dissection between 1989 and 2003, of whom 58 patients had proximal aortic repair, 62 had distal arch repair, and 62 had total arch repair. We assessed factors associated with the development of vocal cord paralysis and examined in detail the clinical outcome of patients with vocal cord paralysis.

RESULTS

Postoperative vocal cord paralysis occurred in 40 patients. Multiple logistic regression analysis revealed the following risk factors with odds ratios (OR) for vocal cord paralysis: extension of procedures into distal arch (OR, 17.0), chronic dilatation of the aorta at the left subclavian artery (OR, 9.14), and total arch repair (OR, 4.24). Adoption of open-style stent-grafts reduced the incidence of vocal cord paralysis (OR, 0.031). The postoperative occurrence of vocal cord paralysis itself emerges as an independent predictor of pulmonary complications (OR, 4.12) and leads to a longer duration of hospital stay.

CONCLUSIONS

The risk of vocal cord paralysis after aortic arch surgery depends on surgical factors, such as aneurysmal involvement of the distal arch, or the application of newer, less invasive surgical procedures. Vocal cord paralysis after aortic arch surgery itself, under aggressive postoperative respiratory management, did not increase aspiration pneumonia but was associated with postoperative complications leading to higher hospital mortality and prolonged hospitalization.

Evolution of Risk for Neurologic Deficit After Descending and Thoracoabdominal Aortic Repair

BACKGROUND

Cross-clamp time has been reported to correlate with risk of neurologic deficit after thoracoabdominal aortic aneurysm repair. Introduction of cerebrospinal fluid drainage and distal aortic perfusion (adjunct) has greatly reduced the incidence of neurologic deficit. We reevaluated the effect of cross-clamp time before and after introduction of adjunct during a 13-year period.

METHODS

Between 1991 and 2004, we repaired 1,106 thoracic and thoracoabdominal aortic aneurysms. Four hundred one patients were female and 705 were male (median age, 67 years). Selective use of adjunct was begun in late 1992, with its routine use by 1993.

RESULTS

Aortic cross-clamp times have increased significantly (34 seconds/year; p < 0.0001) since 1991. Despite this increase in cross-clamp time, neurologic deficit rates have declined from the first to the fourth quartile (p < 0.02). This decrease in neurologic deficit is most pronounced with the extent II thoracoabdominal aortic aneurysms (21.1% to 3.3%). The use of the adjunct increased the cross-clamp time by a mean of 12 minutes (p < 0.0001), but was associated with a significant protective effect against neurologic deficit (odds ratio = 0.4; p < 0.0002). Although other previously established risk factors remained significantly associated with neurologic deficit, cross-clamp time is no longer significant.

CONCLUSIONS

Adjunct significantly reduced the risk of neurologic deficit, despite increasing cross-clamp time. The use of the adjunct appears to blunt the effect of the cross-clamp time and may provide the surgeon the ability to operate without being hurried. Because cross-clamp time has been effectively eliminated as a risk factor with the use of the adjunct, using this variable to construct risk models becomes irrelevant in our experience.

Ten years experience of thoracic and thoracoabdominal aortic aneurysm surgical repair: lessons learned

In the last few years, advances in surgical techniques and in organ protection adjuncts have improved outcomes in thoracic (TAA) and thoracoabdominal aortic aneurysm (TAAA) surgical repair, although mortality and morbidity are still noteworthy. The aim of the current retrospective study is to determine whether the use of adjuncts influenced mortality and morbidity rates. From 1993 to 2003 we performed 353 procedures for TAA (175 cases) and TAAA (178 cases). This series has been divided into two consecutive groups: in group I (from 1993 to 1997), distal aortic perfusion with left atriofemoral bypass and cerebrospinal fluid drainage were used selectively, and in group II (from 1998 to 2003), the adjuncts were used routinely (together with surgical techniques of less invasive approach in selected cases). Total in-hospital mortality rates were significantly different ( p < 0.05): 15.9% in group I and 8.6% in group II. The overall incidence of paraplegia or paraparesis in group I was 8.3% and in Group II it was 5.1%. Renal failure occurred in 9.6% of group I and in 4.1% of group II. The incidence of respiratory failure in group I was 28%, and was 17.9% in group II. Respiratory failure was significantly lower ( p < 0.05) in group II. The reduction in the incidence of renal failure and paraplegia in the two groups was nonsignificant. In conclusion, the use of adjuncts and our improved experience allowed us to achieve a significant improvement in mortality and major morbidity rates in the group of patients operated on after 1998.

Descending Thoracic and Thoracoabdominal Aortic Aneurysm Repair: 15-Year Results Using a Uniform Approach

This review presents the results of surgical repair of descending thoracic (DT) and thoracoabdominal aortic (TAA) aneurysms, using spinal drainage (SD) distal aortic perfusion (DAP), and other adjuncts intended to reduce complications. Records of patients undergoing repair of DT and TAA between 1986 and 2002 were reviewed. Elective operations were performed using single lung ventilation, invasive monitoring, SD, modest anticoagulation, permissive hypothermia (> or = 33 degrees F), liberal use of transaortic endarterectomy, and complete repair. Intercostal arteries were reimplanted when possible and DAP was used in DT and TAA types I, II, and III repair. Exceptions to this approach were noted. Some of these adjuncts were used in emergency cases. Actuarial survival was calculated. Fifty consecutive patients with DT (3) or TAA (47), type I (4), type II (16), type III (18), or type IV (9), aneurysms received elective (36) or emergency (14) repair between 1986 and 2002. Mortality was 2/36 (5.5%) in the elective group. In the emergency group, there were 2 intraoperative deaths and mortality was 4/14 (28.5%, p < 0.07). Overall survivor morbidity was 6/34 (17.6%) in elective and 7/10 (70%, p < 0.02) in emergency cases. Paraplegia occurred in one patient in the elective group (2.7%) with dissecting type II TAA aneurysm in whom the intercostal patch was sacrificed. Two of 12 initial survivors developed paraplegia in the emergency group (16.7%); one had SD but neither had DAP or intercostal reimplantation. Serious complications were associated with avoidable deviations from the approach. Five and 10-year survival for the entire series was 64.8% and 46.4%, respectively. These results parallel those in contemporary reports from centers where repair of descending and thoracoabdominal aortic aneurysm is frequently performed. Good long-term results can be achieved using spinal drainage and distal aortic perfusion, combined with other adjuncts as a means of reducing complications. When possible, the same approach should be used in emergency cases.

Iatrogenic-induced dysfunction of the neuromuscular respiratory system

In the presence of respiratory symptoms that are associated with alveolar hypoventilation or a restrictive ventilatory defect and in the absence of parenchymal or pleural abnormalities on the chest radiograph, iatrogenic causes must be evoked, exactly as they are in the presence of interstitial lung disease. In most cases, the anamnestic and clinical contexts provide a strong diagnostic presumption. It is important to establish carefully the mechanism of the observed disorders, using the currently available arsenal of diagnostic tools for clinical and prognostic reasons and from a medicolegal standpoint. It is necessary to evaluate precisely the clinical repercussions of the respiratory neuromuscular abnormality to serve as a basis for follow-up and to discuss therapeutic options in certain cases (eg, nocturnal ventilation to correct nocturnal hypoventilation due to diaphragmatic dysfunction, diaphragm plication to alleviate dyspnea after complete phrenic nerve destruction, phrenic nerve pacing), again in the perspective of medicolegal actions.

Estimating group mortality and paraplegia rates after thoracoabdominal aortic aneurysm repair

BACKGROUND

Most clinical studies regarding thoracoabdominal aortic aneurysm (TAAA) surgery are retrospective comparisons involving heterogeneous groups of patients. Risk models that evaluate susceptibility bias enhance interpretation of these intergroup comparisons. The purpose of this analysis was to derive group risk models for mortality and paraplegia after TAAA repair.

METHODS

Data regarding 1,220 consecutive patients undergoing TAAA repair were analyzed via multiple logistic regression with stepwise model selection. Categorical preoperative risk factors that predicted 30-day mortality and paraplegia were used to develop risk models.

RESULTS

Fifty-eight patients (4.8%) died within 30 days and 56 patients (4.6%) developed paraplegia or paraparesis. Predictors of mortality were rupture, renal insufficiency, symptomatic aneurysms, and Crawford extent II repairs. Extent of repair and acute presentation were predictors of paraplegia. The derived risk models estimated mortality and paraplegia rates that correlated well with actual frequencies reported in other contemporary series (regression slopes = 0.87 and 1.06, respectively).

CONCLUSIONS

The derived risk models accurately estimate paraplegia and mortality rates in groups of patients. Prospective model validation will be required to confirm their accuracy.

Morbidity and mortality after extent II thoracoabdominal aortic aneurysm repair

BACKGROUND

Surgical repair of Crawford extent II thoracoabdominal aortic aneurysms (TAAAs) carries substantial risk for morbidity and mortality. The purpose of this study was to analyze the results of a large consecutive series of extent II TAAA repairs and identify factors that influence morbidity and survival.

METHODS

Of 1,415 consecutive patients who underwent TAAA operations over a 13-year period, 442 (31.2%) had extent II repairs. Data from a prospectively maintained database were analyzed to determine which factors were associated with death and major complications.

RESULTS

The operative mortality was 10.0% (44 patients). Postoperative complications included paraplegia/paraparesis in 33 patients (7.5%), pulmonary complications in 158 (35.7%), and renal failure in 69 (15.9%). Multivariable analysis revealed that renal insufficiency (odds ratio [OR] 2.6), increasing age (OR 1.1/year), and increasing red blood cell transfusion requirements (OR 1.1/U) were predictors for mortality; renal insufficiency (OR 2.8) and peptic ulcer disease (OR 9.3) were predictors of renal failure; and rupture (OR 6.3) was a predictor of paraplegia. Left heart bypass was an independent protective factor against paraplegia (OR 0.4).

CONCLUSIONS

This contemporary experience demonstrates acceptable levels of morbidity and mortality in this high-risk group. Left heart bypass was found to provide protection against paraplegia in these patients.

Determinants of hospital length of stay after thoracoabdominal aortic aneurysm repair

PURPOSE

Extended hospital length of stay (LOS) and consequent high costs are associated with thoracic and thoracoabdominal aortic aneurysm (TAAA) surgery. In this study, we examined factors that may influence LOS after TAAA repair.

METHODS

Five hundred forty thoracic and TAAA repairs were performed by one surgeon between 1990 and 1999. The data were analyzed with multiple linear regression with appropriate logarithmic transformation. The predictor variables included patient demographics, disease extent, severity indicators, intraoperative factors, and postoperative complications.

RESULTS

The median LOS was 15 days. Postoperative creatinine level of greater than 2.9 was the most important predictor of LOS, followed by spinal cord deficit, age, and pulmonary complication (all statistically significant with P <.05). A second model constrained to preoperative risk factors showed both age and complete diaphragmatic division to be associated with increased LOS. Preservation of the diaphragm led to reduced LOS by an average of 4 days. The adjunct cerebrospinal fluid drainage and distal aortic perfusion was associated with a decrease in LOS, although it did not reach statistical significance.

CONCLUSION

Renal failure, spinal cord deficit, and pulmonary complication were the major determinants of LOS in patients for TAAA repair. This study shows that the preservation of diaphragmatic function and the use of the adjunct distal aortic perfusion and cerebrospinal fluid drainage may reduce hospital LOS.

Factors affecting outcome in proximal abdominal aortic aneurysm repair

Sixty-five consecutive patients undergoing nonemergent repair of an abdominal aortic aneurysm (AAA) originating above the visceral and/or renal arteries were studied to determine operative results and identify factors influencing outcome of proximal AAA repair. Factors associated with postoperative morbidity were analyzed using multivariate analysis. There were no postoperative deaths, paraplegia/paraparesis, or symptomatic visceral ischemia. Proximal AAA repair can be accomplished with acceptable mortality. If renal artery bypass or reimplantation is anticipated, cold renal perfusion may protect against renal dysfunction. Postoperative pulmonary dysfunction can be reduced by avoiding radial division of the diaphragm.

Perioperative Ventilation of the Vascular Surgery Patient

Although cardiovascular disease represents the most com mon comorbidity in patients undergoing vascular surgery, perioperative ventilatory issues can also play a vital role in achieving good outcomes. Postoperative respiratory failure is uncommon after carotid endarterectomy or peripheral revascularization procedures, the risk of pulmonary compli cations following intra-abdominal or intrathoracic vascular surgery is high. In addition to primary lung diseases such as chronic obstructive pulmonary disease, associated organ dysfunction syndromes such as stroke, renal failure, and congestive heart failure can also contribute to respiratory morbidity. An approach to minimizing respiratory complica tions begins with a careful preoperative search for ways to maximize pulmonary function and establishment of targets for postoperative weaning. Intraoperative attention should be paid to intraoperative management of bronchospasm, auto-positive end-expiratory pressure, and acid-base status. Postoperative management should strive for rapid extuba tion, continuation of pharmacologic conditioning programs begun preoperatively, and consideration of the use of post operative regional analgesia for patients with severe lung disease.

How I do it: thoracoabdominal aortic aneurysm graft replacement

A technique of aortic graft replacement in thoracoabdominal aortic aneurysm repair is described. The author's experience with the surgical adjuncts of cerebrospinal fluid drainage and distal aortic perfusion, and the evolution and rationale of thoracoabdominal aortic aneurysm classification are discussed. Interpretation of the large amount of data that the author has accumulated would have been impossible without such a system.

Thoracoabdominal aortic aneurysm repair: how I do it

There remains no consensus on the operative management of Thoracoabdominal aortic aneurysm (TAA). Our approach emphasizes operative expediency and simplicity (without circulatory assist techniques), avoiding anticoagulation and systemic hypothermia. The technique involves a fundamental clamp/sew method with specific adjuncts directed against the principle complications: epidural cooling (introduced in 1993) for spinal cord protection, regional renal hypothermia, and in-line mesenteric shunting to minimize visceral ischemia. In a cohort of over 200 TAA patients (50% Types I & II) treated during the past decade perioperative mortality has been 8% and paraparesis/paraplegia occured in 7%. These figures are halved for patients treated in elective circumstances.