Ideal or actual body weight to calculate CD34+ cell doses for allogeneic hematopoietic stem cell transplantation?

The number of CD34+ cells infused influences hematologic recovery after transplantation. Limited data suggest that cell dose should be based on ideal (IBW) rather than actual (ABW) body weight for autotransplantation, but none in allografts. We compared the correlation between recovery to 0.5 x 10(9)/l neutrophils and the CD34+ cell dose based upon ABW and IBW in 78 allograft recipients. ABW was > or =25% over IBW in 47% of patients. The median CD34+ cell dose was 5.1 x 10(6)/kg IBW and 4.4 x 10(6)/kg ABW. The time to neutrophil recovery was 8-26 days (median 12). There was a stronger inverse correlation between CD34+ cell dose/IBW and neutrophil recovery (r(2)=0.160; P<0.0001) than between CD34+ cell dose/ABW and neutrophil recovery (r(2)=0.138; P=0.001). When neutrophil recovery in patients receiving <3 or <5 x 10(6) CD34+ cells/kg was compared to those receiving > or =3 or > or =5 x 10(6) CD34+ cells/kg, respectively, separately by IBW and ABW, the magnitude and significance of the differences were greater for IBW-based comparisons. These data suggest the CD34+ cell dose based on IBW is a better predictor of neutrophil recovery after allografting. Further work in a larger, more homogeneous group of patients is required to confirm this observation.

BioGlue surgical adhesive for thoracic aortic repair during coagulopathy: efficacy and histopathology.

BACKGROUND: We hypothesized that induction of coagulopathy in sheep would model clinical needle hole and surgical bleeding from synthetic graft anastomoses, and that a new tissue bioadhesive (BioGlue) would control postoperative blood loss during surgical repair of the thoracic aorta. METHODS: Sheep were anticoagulated with aspirin and heparin. A bypass was made using end-to-side anastomoses of a graft to a partially occluded descending thoracic aorta. Experimental anastomoses (EXP, n = 9) were treated with BioGlue, and control anastomoses (CON, n = 5) were treated with Surgicel to gain intraoperative hemostasis. RESULTS: EXP animals exhibited significantly reduced postsurgical bleeding (CON median 955 mL versus EXP median 470 mL, p < 0.003), a reduced rate of blood loss over the first 2 postoperative hours (CON median 210 mL/hr versus EXP median 92.5 mL/hr, p < 0.006), and over the entire recovery period (CON median 158 mL/hr versus EXP median 86 mL/hr, p < 0.05), and reduced total blood loss (CON mean 1,497 +/- 691 mL versus EXP mean 668 +/- 285 mL, p < 0.008). On histologic examination of tissues explanted after 3 months, BioGlue was relatively inert and demonstrated a minimal inflammatory response. CONCLUSIONS: The use of BioGlue significantly reduced the volume and rate of postsurgical bleeding in a coagulopathic sheep model for thoracic aortic operations. Histopathologically, BioGlue generated only a minimal inflammatory response. This new surgical tissue bioadhesive should prove extremely beneficial for coagulopathic patients undergoing thoracic aortic or vascular procedures.

A novel technique in a sheep model for evaluating prosthetic heart valve performance.

There have been many various animal studies to evaluate the structural integrity and antithrombogenicity of prosthetic heart valves. We were interested in developing a novel sheep model to study the thrombogenicity of mechanical heart valves placed into the systemic circulation but without the need for cardiac bypass. Also, we wanted to minimize the risk ofparaplegia from complete thoracic aortic clamping. Six sheep underwent left lateral thoracotomy for placement of a mechanical heart valve in parallel with the descending thoracic aorta. A valved conduit with a dacron tube graft sutured to the back end was fashioned. Employing partial aortic occlusion with a side-biting clamp, the proximal and distal ends were anastomosed in an end-to-side fashion. Once flow was confirmed through the graft, the native aorta was occulded with umbilical tape. The sheep received no postoperative anticoagulation. The median operative time and estimated blood loss (EBL) was 170 min and 250 cc, respectively. Patency of the valved conduits was confirmed during the initial procedure, and there was no incidence of paraplegia postoperatively. Two animals expired shortly after extubation and at necropsy the valved conduits were patent with preserved valve function. The four survivors were sacrificed a median of 37 days postoperatively. Prior to euthanasia, the valved conduits were evaluated in situ with ultrasound. In all cases, the valves had clot formation at the hinges, which prevented active movement of the leaflets. This novel in vivo technique provides an alternative in testing the thrombogenicity of prosthetic heart valves without cardiac bypass or the risk of paraplegia in an animal that is extremely sensitive to complete aortic cross-clamp.

Hemangioma of the right ventricular outflow tract.

Obstruction of the right ventricular outflow tract by a primary cardiac tumor is rare. Six cases of right ventricular outflow tract obstruction by a primary cardiac hemangioma have been reported; all but one were detected before the age of 25 years. In this report, we review the literature and describe what we believe to be only the second reported case of right ventricular outflow tract obstruction produced by a cardiac hemangioma that presented in late adulthood.

A sheep model for thoracic aortic surgery in the presence of systemic coagulopathy.

Surgical repair of aneurysms, traumatic injuries, or congenital anomalies of the thoracic aorta are associated with high morbidity and mortality mainly as a result of excessive and uncontrollable hemorrhage from diffuse coagulopathy. We developed a model in sheep that simulates this coagulopathic state for experimentation with thoracic aorta surgery. This experimental animal model involves administering a 600-mg aspirin suppository once a day for the 2 days preceding surgery and a final dose on-call to surgery. Prior to cross-clamping the aorta, an intravenous (i.v.) bolus of heparin (400 IU/kg) was administered. Thirty minutes later, the i.v. heparin bolus was repeated. Pre- and intraoperative activated clotting time was 101 +/- 10 s and >1500 s (p < .0001); prothrombin time, 21 +/- 1 s and >100 s (p < .0001); and activated partial thromboplastin time, 20 +/- 1 s and >50 s (p < .0001), respectively. We utilized a partial cross-clamp-and-sew technique to anastomose a woven, gelatin-impregnated, 16-mm tube graft end-to-side to the descending thoracic aorta. Mean total blood loss was 1367 +/- 282 mL, which included mean blood loss from time of release of aortic cross-clamp to close (422 +/- 135 mL) and mean total blood output from chest tube drain (945 +/- 203 mL). The mean time to achieve hemostasis at suture lines after aortic cross-clamp release was 15.5 +/- 6.6 min. In conclusion, a sheep model with induced coagulation defects was successfully developed and reproducible for experimentation involving thoracic aortic surgery.

Diamond-like carbon coating and plasma or glow discharge treatment of mechanical heart valves.

All mechanical heart valves (MHV) are thrombogenic. Application of surface modification technology to reduce the incidence of thrombus formation on MHV is a novel undertaking. This requires collaboration within the bioengineering and cardiothoracic surgery fields. From reviewing results of recent and past investigations, and our own preliminary study with diamond-like carbon coating (DLC) and plasma or glow discharge treatment (GDT) of MHV, we identify and discuss several potentially beneficial effects that may reduce the extent of valve-related thrombogenesis by surface modification. DLC and GDT may affect the surfaces of MHV in many ways, including cleaning of organic and inorganic debris, generating reactive and functional groups on the surface layers without affecting their bulk properties, and making the surfaces more adherent to endothelial cells and albumin and less adherent to platelets. These different effects of surface modification, separately or in combination, may transform the surfaces of MHV to be more thromboresistant in the vascular system.

Lorazepam and midazolam in the intensive care unit: a randomized, prospective, multicenter study of hemodynamics, oxygen transport, efficacy, and cost.

OBJECTIVES: To evaluate and compare the clinical efficacy, impact on hemodynamic and oxygen transport variables, safety profiles, and cost efficiency of sedation and anxiolysis with lorazepam vs. continuous infusion of midazolam in critically ill, intensive care unit patients. DESIGN: Multicenter, prospective, randomized, open-label study. SETTING: Teaching hospitals. PATIENTS: Ninety-five critically ill, mechanically ventilated patients with fiberoptic pulmonary artery catheters in place were randomly assigned to receive short-term (8 hrs) sedation with either intermittent intravenous injection lorazepam (group A, n = 50) or continuous intravenous infusion midazolam (group B, n = 45) titrated to clinical response. MEASUREMENTS AND MAIN RESULTS: The severity of illness, demographic characteristics, levels of anxiety and agitation, hemodynamic parameters, oxygen transport variables, quality of sedation, nursing acceptance, and laboratory chemistries reflecting drug safety were recorded. There were no significant differences with regard to demographic data, hemodynamic and oxygen transport variables, or levels of anxiety/agitation between the two groups at baseline, 5 mins, 30 mins, and 4 and 8 hrs after administration of sedation. There were no significant differences in the quality of sedation or anxiolysis. Midazolam-treated patients used significantly larger amounts of drug for similar levels of sedation and anxiolysis (14.4 +/- 1.2 mg/8 hrs vs. 1.6 +/- 0.1 mg/8 hrs, p = .001). Both drugs were safely administered and patient and nurse satisfaction was similar. CONCLUSIONS: Sedation and anxiolysis with lorazepam and midazolam in critically ill patients is safe and clinically effective. Hemodynamic and oxygen transport variables are similarly affected by both drugs. The dose of midazolam required for sedation is much larger than the dose of lorazepam required for sedation, and midazolam is therefore less cost-efficient.

Comparison of antegrade with antegrade/retrograde cold blood cardioplegia for myocardial revascularization.

There has been increasing interest in the use of retrograde coronary sinus perfusion for delivery of cardioplegic solution during myocardial revascularization. Despite evidence of improved cardiac protection, it is unclear if a combined antegrade/retrograde approach to myocardial preservation offers significant clinical benefits. One hundred twenty patients undergoing elective 1st-time coronary bypass surgery for 3-or-more-vessel disease received aortic root, antegrade cold blood cardioplegia (Group I, n=52) or combined antegrade/retrograde cardioplegia via coronary sinus cannulation (Group II, n=68). All preoperative variables were similar, including age, severity of coronary artery disease, functional status, and ejection fraction. Intraoperative and postoperative variables, including the degree of hypothermia, temperature of infusion solution, number of bypass grafts, defibrillation attempts and spontaneous return to sinus rhythm, the use of intraaortic balloon pump counterpulsation, and inotropic support during weaning from cardiopulmonary bypass, were not statistically different. Cardioplegia infusion time was longer in Group II than in Group I (2.5 +/- 0.8 vs 1.7 +/- 0.7 min, p < 0.05). The postoperative cardia output, electrocardiographic and cardiac enzyme evidence of ischemia, the need for temporary pacing, and 30-day morbidity were similar for both groups. The data indicate that in this non-risk-stratified group of patients, the route of cardioplegia administration is not a determinant of clinical outcome.

Descending thoracic aortomyoplasty: a technique for clinical application.

BACKGROUND: Descending thoracic aortomyoplasty is a form of skeletal muscle-powered cardiac assistance. Its use in clinical settings has been limited by the ligation of intercostal arteries necessary to complete a circumferential wrap of the aorta with the latissimus dorsi. METHODS: This study assessed the feasibility and the efficacy of aortomyoplasty constructed with a modified latissimus dorsi. A pericardial patch was attached to the latissimus dorsi and divided around the preserved intercostal arteries. Nine alpine goats (37 +/- 2 kg) underwent descending aortomyoplasty using this technique. All intercostal arteries were preserved. After a 6-week recovery period, the animals underwent a 6-week, incremental electrical conditioning program. After 90 postoperative days, animals were examined under anesthesia with the myostimulator on and off. RESULTS: Aortomyoplasty activation resulted in augmentation of mean diastolic aortic pressure by 16.0 +/- 0.9 mm Hg (23%). Significant improvements in cardiac index (40%), stroke volume index (37%), left ventricular stroke work index (49%), and mean arterial pressure (19%) were noted. An intravascular sonographic probe placed in the descending aorta revealed circumferential compression of the aorta during counterpulsation. Mean cross-sectional aortic area was reduced by 51.8%, from 210.1 +/- 7.1 to 108.9 +/- 6.7 mm2 during aortomyoplasty activation (p < 0.05). Histologic analysis confirmed the long-term patency of intercostal arteries. CONCLUSIONS: Descending aortomyoplasty, modified with an interposing patch of pericardium, effectively transfers skeletal muscle force across the aortic wall and assists cardiac function. This technique allows preservation of all aortic branches, and with this novel approach, the clinical utility of aortomyoplasty can now be explored.

Predictors of stroke after cardiac surgery.

From January 1, 1988 to September 30, 1993, 44 of 2,455 patients undergoing cardiac surgery for acquired heart disease at our institution sustained an intraoperative or postoperative cerebrovascular accident (CVA). Demographic data, atherosclerosis risk factors, past medical history, cardiac catheterization reports, and intraoperative findings were retrospectively reviewed. The highest rate of CVA was in the sub-group of patients undergoing simultaneous myocardial revascularization and carotid endarterectomy (18.2%). The lowest rate was in a group of patients who underwent aortic valve replacement (0.9%). Severe aortic arch atherosclerosis with the presence of atheromatous material or calcinosis at the cannulation site was identified intraoperatively in 43.2% of patients with neurological complications and in 5% of the group without CVA (x2 = 18.1, p = 0.0001). Of 44 patients with CVA, 13.6% had a history of preoperative completed stroke. CPB time was 90.1 +/- 4.9 min vs. 71.6 +/- 3.7 min (p = 0.004), and aortic cross-clamping time was 54.5 +/- 3.2 min compared to 39.8 +/- 2.7 min (p = 0.001) in groups with and without postoperative stroke, respectively. Hypertension was an independent risk factor of postoperative CVA (x2 = 9.5, p = 0.02), but age was not. Neurological complications correlated with high operative mortality (38.6%) and prolonged postoperative hospital stays (35.1 +/- 5.3). These data describe predictors for the development of post-cardiopulmonary bypass CVA and identify a high-risk subgroup for neurological events. The preoperative recognition of risk factors is an essential step toward the reduction of morbidity and mortality.

Latissimus dorsi and serratus anterior dynamic descending aortomyoplasty for ischemic cardiac failure.

Dynamic descending aortomyoplasty for cardiac assistance is a form of extraaortic, skeletal muscle-driven counterpulsation. Controversy exists regarding its clinical applicability and the most suitable muscle autograft for the procedure. Specifically, the ligation of intercostal vessels required for descending aortomyoplasty may not be tolerated clinically. This study compared the hemodynamic profiles and long-term function of latissimus dorsi (LD) aortomyoplasty to a split serratus anterior (SA) descending aortomyoplasty in which all intercostal vessels were preserved. Descending aortomyoplasty was performed in 11 goats. In 5, the SA was harvested and its distal end divided, facilitating a wrap of the aorta without ligation of intercostal arteries. In 6, the LD was used as a circumferential aortic wrap. At 90 days, an occluder placed on the left anterior descending artery created an ischemic event. Hemodynamic studies with and without assistance were performed in the ischemic and nonischemic states. Latissimus dorsi aortomyoplasty improved cardiac output 24% and 5.6%, stroke volume 29% and 66%, left ventricular stroke work index 30% and 166%, and coronary flow 4% and 3% in the normal and ischemic heart, respectively. Serratus anterior aortomyoplasty improved cardiac output 36% and 10%, stroke volume 42.8% and 13.5%, left ventricular stroke work index 64% and 21%, and coronary flow 8% and 4.3%, in the normal and ischemic heart, respectively. Two of the SA autografts were fibrotic and nonfunctional at 3 months. Aortomyoplasty with either SA or LD muscle improves cardiac function in the normal and ischemic heart. However, divided SA is associated with a higher rate of fibrosis and may be less suitable for the procedure.

The pivotal role of transesophageal echocardiography in the management of traumatic thoracic aortic rupture with associated intra-abdominal hemorrhage.

Rupture of the thoracic aorta after blunt trauma, particularly when associated with multiple injuries, presents a major problem of resuscitation and management. Transesophageal color Doppler echocardiography (TEE) during laparotomy played a major role in confirming the diagnosis of thoracic aortic rupture in a patient.

Improvement in circulatory and oxygenation status by perflubron emulsion (Oxygent HT) in a canine model of surgical hemodilution.

To examine the effect of a low dose of Oxygent HT on hemodynamics and oxygen transport variables in a canine model of profound surgical hemodilution, two groups of adult anesthetized splenectomized beagles were hemodiluted with Ringer's solution to Hb 7 g/dL. The treated group received 1 mL/kg Oxygent HT (90% w/v perflubron emulsion [perfluorooctyl bromide], Alliance Pharmaceutical Corp.) and both groups (7 controls and 10 treated) were further hemodiluted using 6% hydroxyethyl starch until cardiorespiratory decompensation occurred. Pulmonary artery catheterization data and oxygen transport variables were recorded at Hb decrements of 1 g/dL breathing room air. There was no difference among groups during initial hemodilution. However, in the Oxygent HT group there was a statistically significant improvement in mean arterial pressure, CVP, cardiac output, PvO2, SvO2, DO2, and pulmonary venous admixture shunt during profound hemodilution to Hb levels of 6, 5, and 4 g/dL. A low dose of Oxygent HT offered benefit in improving hemodynamics and oxygen transport parameters even under air breathing conditions in a model of surgical hemodilution. This effect was most apparent at lower levels of Hb.

Simultaneous coronary artery bypass and carotid endarterectomy. Determinants of outcome.

From January of 1988 to May of 1993, simultaneous single-stage coronary revascularization and carotid endarterectomy was performed in 33 patients (mean age, 69 years). Thirty-one patients (94%) were in New York Heart Association class III or IV, 15 (46%) had unstable angina, and 7 (21%) were operated on because of evolving myocardial infarction. One or more previous myocardial infarctions were present in 18 patients (54%). Nineteen patients (58%) presented with neurologic symptoms, and 22 (67%) had severe bilateral carotid stenosis. Thirty (91%) had triple-vessel or left main coronary artery disease. Sequential reconstruction of the carotid artery followed by coronary artery bypass grafting was performed in all patients. In 4 cases, additional cardiac procedures were performed. Operative mortality (6%) was cardiac related. Perioperative morbidity included myocardial infarction in 1 patient (3%) and neurologic deficit in 6 (18%), with permanent functional impairment in 2 patients (6%). The stroke rate was higher in the bilateral than in the unilateral carotid stenosis group (22.7% vs 9.1%, p = 0.047). Previously completed stroke influenced the operative outcome (55.6% vs 4.2%, p = 0.003). Low ejection fraction (33.5% +/- 7.5% vs 52.8% +/- 3.5%, p = 0.03) and left main coronary artery disease (36% vs 5%, p = 0.03) also predicted postoperative neurologic complications. During a mean follow-up of 24.6 +/- 3.5 months, 3 patients died. The 5-year life-table survival rate was 85%. Eighty-nine percent of long-term survivors were free of cardiovascular disease symptoms. Our results show that the out come of simultaneous carotid endarterectomy/coronary artery bypass grafting in this high-risk population depends upon the preoperative absence or presence of completed stroke or bilateral carotid stenosis, upon the preoperative ejection fraction, and upon the extent of the left main coronary artery disease.

Effect of sodium nitroprusside on paraplegia during cross-clamping of the thoracic aorta.

Sodium nitroprusside (SNP) is usually used to control excessive proximal pressure after aortic cross-clamping. To assess the effect of SNP on circulatory dynamics, somatosensory evoked potentials, and neurologic outcome, 10 adult mongrel dogs that underwent 45 minutes of cross-clamping of the thoracic aorta were randomly assigned to receive either 50 mg/kg of SNP or no treatment for excessive proximal hypertension. There was a statistically significant difference noted between the SNP-treated animals and the control animals in terms of the proximal mean arterial pressures (112 +/- 13 versus 142.2 +/- 15 mm Hg, respectively; p < 0.05) and the mean distal arterial pressures (15 +/- 3 mm Hg versus 23 +/- 1 mm Hg; p = 0.04). However, the electrical activity of the spinal cord, as indicated by the somatosensory evoked potentials, returned significantly faster in the nontreated group than in the SNP-treated group (15 +/- 9 versus 44 +/- 13 minutes; p < 0.05). Control animals exhibited a significantly better neurologic outcome and no paraplegia 24 hours postoperatively. We conclude that the use of SNP to treat excessive proximal hypertension may be detrimental to the spinal cord during cross-clamping of the thoracic aorta, resulting in a decline in the ischemic tolerance.

A surgical approach to chronic aortomyoplasty in the goat model.

The left latissimus dorsi skeletal muscle of seven male goats was prepared and applied circumferentially to the descending aorta just below the subclavian artery. Stimulation of the neural pedicle of the latissimus dorsi was performed in an attempt to convert it to a fatigue-resistant cardiac-like muscle. Timing of the stimulus was in diastole. Biochemical assays established the conversion, and echocardiography demonstrated aortic compressions in the area of the muscle wrap. Although limited in numbers, the converted latissimus dorsi muscle in the extra-aortic position appears to provide diastolic augmentation.

Transfusion guidelines for cardiovascular surgery: lessons learned from operations in Jehovah's Witnesses.

Patients undergoing cardiovascular surgery are among the top users of homologous blood transfusion (HBT). Awareness of the risks of disease transmission and immune system modulation from HBT has prompted us to find alternatives such as autologous predonation (APD) and intraoperative autotransfusion (IAT). However, these latter options are not appropriate for all patients. We reviewed our experience with 59 Jehovah's Witness patients who underwent 63 elective cardiovascular procedures without either HBT or APD to determine the safety of operation without these modalities and to develop revised maximum surgical blood-ordering schedule guidelines for cardiovascular surgery. Estimated blood loss averaged 870 ml, but one third to one half of losses were replaced by IAT. IAT was not needed in lower extremity bypass operations in which the estimated blood loss was less than 150 ml. Three of 59 patients died (5.1%), but only one died of operative bleeding complications. We conclude that (1) elective cardiovascular operations can be done safely without the use of either HBT or APD, (2) HBT is not necessary in leg bypass procedures, and (3) maximum surgical blood-ordering schedule guidelines for HBT in major cardiovascular operations can be reduced to near zero by the use of intraoperative autotransfusion and acceptance of a postoperative hemoglobin nadir of 7.0 gm/dl.

Implantation of a cardioverter-defibrillator after coronary artery bypass surgery.

The implantable cardioverter-defibrillator (ICD) has been used in conjunction with surgical coronary revascularization for prevention of postoperative malignant arrhythmias. However, there is no consensus regarding which patient should receive concomitant insertion of the ICD system in a one stage (patches and generator) or two stage (patches, and subsequent implantation of the generator) procedure. To assess differences in hospital course and outcome, the authors studied 8 survivors of sudden death syndrome and 17 patients with preoperative ventricular tachycardia refractory to conventional antiarrhythmic therapy who underwent coronary revascularization and prophylactic implantation of an ICD system in either one or two stages. Patients with advanced coronary disease, poor ventricular function, and silent ischemia received the ICD system in one stage. Those with good ventricular function and well defined coronary pathology received only patches concomitant with myocardial revascularization. Seventy-nine percent of the patients with patches needed subsequent implantation of the ICD generator, as determined by postoperative electrophysiologic studies. There were three postoperative deaths unrelated to arrhythmias. There was no difference between the groups regarding the number of ICD discharges. It was concluded that the prophylactic use of the ICD system is an important adjuvant in the treatment of postoperative malignant arrhythmias for patients undergoing myocardial revascularization. The insertion of the ICD, however, should be based on pathophysiologic considerations and postoperative electrophysiologic findings. This may result in important savings in terms of unnecessary cost and operative procedures.

Determinants of outcome in lesions of the thoracic aorta in patients with multiorgan system trauma.

Of all patients presenting at our level 1 trauma center with multiorgan system injuries, 33 have been identified with acute lesions of the thoracic aorta. Mean severity injury score was 24 +/- 3. Four patients underwent resuscitative thoracotomy upon arrival in the emergency department. One survived and fully recovered. The rest underwent diagnostic procedures and repair of aortic lesions in conjunction with surgical treatment of other injured organ systems. The overall survival rate was 82 percent. Survivors arrived significantly faster to the ED and had lesser degree of multiorgan system injuries. There was no difference in the time spent to make the diagnosis of acute aortic disruption for survivors and nonsurvivors, nor was a difference in time to arrive in the operating room once the diagnosis of aortic injury has been established. Morbidity was related to ischemia to distal organs in four patients of whom two presented with multiple lesions of the thoracic aorta; two remained paralyzed and two had only lower limb spasticity. All discharged survivors were alive at 12 months' follow-up. The type of surgical repair did not influence the outcome of patients with single, typical aortic lesions; however, "clamp/sew" technique was not adequate when multiple aortic tears were found intraoperatively. The outcome of surgical treatment of the traumatic aortic lesions of patients with polytrauma may be influenced by the speed of arrival to the ED, the magnitude of multiorgan system involvement, and the application of appropriate surgical technique for repair according to the intrathoracic findings and the timing of aortic repair vis-a-vis other surgical treatment.