Surgical correction of nasal obstruction in the treatment of mild sleep apnoea: importance of cephalometry in predicting outcome.

BACKGROUND--A study was undertaken to determine if cephalometric radiographs could identify those who will benefit from nasal surgery in patients with a sleep apnoea hypopnoea syndrome (SAHS) and chronic nasal obstruction. METHODS--Fourteen patients with SAHS were enrolled. Those with normal posterior airway space and mandibular plane to hyoid bone distances on preoperative cephalometric radiographs were matched with those with abnormal cephalometry for the frequency of sleep disordered breathing and body mass index. Polysomnographic studies (all subjects) and nasal resistance measurements (n = 10) were performed one to three months before and two to three months after surgery (septoplasty, turbinectomy, and polypectomy). RESULTS--There was no difference in the baseline results of the polysomnographic studies between the two groups of patients. Nasal resistance decreased from a mean (SE) value of 2.9 (0.3) cm H2O/l/s before surgery to 1.4 (0.1) cm H2O/l/s after surgery in the normal cephalometry group and from 2.7 (0.3) cm H2O/l/s to 1.3 (0.3) cm H2O/l/s in the other group. The apnoea + hypopnoea index returned to normal (< 10 breathing abnormalities/hour) in all but one subject with normal cephalometric measurements, and sleep fragmentation improved with a decrease in the arousal index from 23.9 (3.3)/hour at baseline to 10.6 (2.5)/hour after surgery. Both of these parameters remained unchanged after surgery in the patients with abnormal cephalometry. CONCLUSIONS--Normal cephalometry is helpful in identifying patients with mild SAHS and nasal obstruction who will benefit from nasal surgery. The presence of craniomandibular abnormalities makes it unlikely that nasal surgery will improve sleep related breathing abnormalities.     

Detection of inspiratory resistive loads after anaesthesia for minor surgery

We measured the ability to detect inspiratory resistances in 22 patients undergoing minor gynaecological surgery, using linear resistances of 1.2-24.4 cm H2O litre-1 s, and ranked 1-9. The rank that could be detected was measured before surgery, approximately 10 min after recovery from anaesthesia, and then 25 min later. After anaesthesia there was a significant increase (P < 0.001) in the rank number by 2, which returned to preoperative values 25 min later. Minute ventilation was reduced by 25% after operation and this may partly explain this change; however, we believe the transient decrease in ability to sense resistance indicates residual effects of anaesthetics and may explain in part the incidence of hypoxia caused by airway obstruction in patients after anaesthesia.      

Is a single preoperative duplex scan sufficient for planning bilateral carotid endarterectomy?

PURPOSE: Duplex scanning is often the sole imaging study before carotid endarterectomy (CEA). Patients with bilateral severe internal carotid artery (ICA) stenosis may be considered for bilateral CEA. High-grade ICA stenosis, however, may artifactually elevate velocity measurements used to quantify stenosis in the contralateral ICA. It is unknown whether ipsilateral CEA will influence duplex determination of the presence of a contralateral 60% to 99% ICA stenosis. This study was performed to determine whether a single preoperative duplex scan is sufficient to plan bilateral CEA. METHODS: Preoperative and early postoperative carotid duplex scans in patients with bilateral ICA stenosis who underwent unilateral CEA were reviewed. Changes in duplex scans that determined stenosis in the ICA contralateral to the CEA were analyzed. Previously validated criteria used to determine 60% to 99% ICA stenosis were a peak systolic velocity (PSV) of 260 cm/sec or more combined with an end diastolic velocity (EDV) of 70 cm/sec or more. RESULTS: Over an 8-year period, 460 patients underwent CEA; 107 patients (23.3%) had an asymptomatic 50% to 99% contralateral ICA stenosis by standard criteria (PSV, >125 cm/sec) and an early postoperative duplex scan examination. Of these 107 patients, 38 patients (35.5%) had duplex scan criteria for 60% to 99% contralateral ICA stenosis. In these 38 patients, there was a mean postoperative PSV decrease of 47.7 cm/sec (10.1%) and a mean EDV decrease of 36.0 cm/sec (19.3%) in the ICA contralateral to the CEA. Eight of 38 (21.1%) preoperative contralateral 60% to 99% ICA lesions were reclassified as less than 60% on postoperative duplex scanning. Six of 69 (8.7%) preoperative lesions of less than 60% were reclassified as 60% to 99% on postoperative duplex scan. These six preoperative examinations were all close to the criteria for 60% to 99% stenosis (mean PSV, 232.5 cm/sec; mean EDV, 62.5 cm/sec). CONCLUSION: One-fifth of patients with apparent 60% to 99% contralateral ICA lesions before the operation have less than 60% stenosis when restudied with duplex scan after unilateral CEA. Lesions below but near the cutoff for 60% to 99% may be reclassified as 60% to 99% on the postoperative duplex scan. These findings mandate that when duplex scanning is used as the sole imaging modality before CEA, patients with severe bilateral carotid stenosis must have an additional carotid duplex examination before operation on the second side.     

鼻内镜下鼻中隔-歪鼻整形术后疗效评估方法的综合应用

目的：探讨鼻内镜下鼻中隔-歪鼻整形术后疗效的综合评估方法。方法：选择2006年12月～2011年12月入住我院整形科和耳鼻喉科需手术治疗的176例歪鼻并鼻中隔偏曲患者,应用VAS主观评估鼻外形满意度及鼻塞情况、鼻外形分度、鼻阻力测定、外鼻相关指标测量的方法对该组患者进行疗效评估。结果：176例患者术后鼻外形满意度为96.02%,100%患者鼻塞改善。从鼻外形分度来看,92.04%患者鼻外形恢复正常,100%的患者治疗有效。鼻阻力测定术后鼻腔0～5cm容积较术前明显增大;术后阻塞侧鼻腔的鼻气道阻力较术前也明显降低,差异具有统计学意义（P〈0.05）。外鼻相关指标的测量,鼻长、鼻深术后较术前有所增加,鼻背坡长、鼻面角、鼻额角、鼻翼角术后较术前有所缩小,差异具有统计学意义（P〈0.05）。结论：对于鼻内镜下鼻中隔-歪鼻整形术后疗效的评估,建议运用综合的评估方法,包括主观鼻外形满意度、鼻塞改善程度,鼻外形分度,鼻阻力测定,外鼻相关指标测量。     

Objective evaluation of anterior septal surgical reconstruction

Fifty patients who underwent nasal septal reconstruction for anterior septal deformities were examined preoperatively and postoperatively with anterior mask rhinomanography. A high degree of correlation was found between the reduction in nasal resistance after operation and the patients' subjective assessment of improvement. Those patients who improved subjectively had a mean decrease in nasal resistance of 1.2 cm H2O/L/sec, whereas those patients who indicated no improvement had a mean increase in nasal resistance of 0.2 cm H2O/L/sec.     

Interrelationships of bladder compliance with age, detrusor instability, and obstruction in elderly men with lower urinary tract symptoms

Data on the interrelationships of bladder compliance (BC), detrusor instability (DI), and bladder outflow obstruction (BOO) in elderly men with lower urinary tract symptoms (LUTS) are scarce and were therefore assessed in this study. Principle inclusion criteria for this study were men aged > or = 50 years suffering from LUTS as defined by an International Prostate Symptoms Score (IPSS) of > or = 7 and a peak flow rate (Qmax) of < or = 15 ml/sec. Patients with previous surgery of the bladder, prostate, or urethra as well as a pathological neurourological status were excluded from this study. The following parameters were studied in all patients: IPSS, prostate volume calculated by transrectal ultrasonography, free uroflow study, post-void residual volume determined by transurethral catheterization, and a multichannel pressure flow study (pQS). A group of 170 men were included in the analysis. The mean BC in the overall group was 32 +/- 2 ml/cm H2O (mean +/- standard error of the mean [SEM]; range, 4-100 ml/cm H2O). In 36.5% of patients, BC was significantly reduced (< or = 20 ml/cm H2O), and in a further 37.1%, it ranged from 20 to 40 ml/cm H2O. BC decreased statistically significantly (p < 0.05) in patients with advanced age, lower Qmax, higher voiding pressures, and larger prostates. In men with DI (n = 61), mean BC was significantly lower (22 +/- 3 ml/cm H2O) compared to those without (37 +/- 3 ml/cm H2O; p = 0.001; n = 109). Patients with severe BOO as defined by a linear passive urethral resistance relationship of > or = 3 (n = 109), had a significantly lower BC (23 +/- 2 ml/cm H2O) compared to those without or minimal obstruction only (39 +/- 3 ml/cm H2O; p = 0.0002; n = 61). Stepwise logistic regression analysis revealed that DI, a low bladder capacity, and a high maximum detrusor pressure were independent predictors of markedly reduced BC (< 20 ml/cm H2O). BC is decreased in elderly men with high voiding pressures, BOO, and DI. The mechanism leading to the reduction of BC under these circumstances is largely unknown and could result from cytostructural alterations of the detrusor and changes in detrusor innervation.     

Effects of catheter size on urodynamic measurements in men undergoing elective prostatectomy

Thirty men undergoing prostatectomy for symptoms of bladder outflow obstruction and low measured maximum flow rates (20 before and 10 after operation) were studied by means of urodynamic investigation. Paired studies were performed on each patient using a large catheter assembly (4 and 10 F) and a small catheter assembly (epidural line, outside diameter 1.1 mm). The order in which the studies were performed was varied randomly. Detrusor pressure at maximum flow rate was significantly greater in the large catheter study (73 +/- 30 cm H2O) than in the small catheter study (65 +/- 27 cm H2O; P less than 0.003). The maximum flow rate was significantly smaller in the large catheter study (8.9 +/- 9.5 ml/s) than in the small catheter study (12 +/- 7 ml/s; P less than 0.001). The increase in detrusor pressure at maximum flow that was noted during the large catheter study was confirmed in the 20 men who were studied before prostatectomy (mean increase 11 +/- 11 cm H2O; P less than 0.001) but no difference was found between the two methods in the 10 men studied after prostatectomy (50 +/- 19 cm H2O and 49 +/- 15 cm H2O). Using a large catheter assembly to perform urodynamic investigations has the advantage that repeated studies can be performed without recatheterisation, but it has the disadvantage of producing a small increase in detrusor pressure at maximum flow in men with symptoms of bladder outflow obstruction. Few errors in diagnosis should result, however, if laboratories using such catheters are aware of this effect and establish their own limit of normal for voiding pressures.     

Lung inflation or mechanical ventilation in extracorporeal circulation?

Extracorporeal circulation (ECC), with its shock-like pulmonary perfusion, leads to pathomorphologic and functional pulmonary changes, the postperfusion syndrome. This study investigated the effects of different types of ventilation during ECC on postoperative pulmonary function and the resulting pulmonary blood gas changes. METHOD. Thirty patients scheduled for aortocoronary bypass surgery were studied. Patients with pre-operative left ventricular end-diastolic pressures exceeding 15 mmHg or signs of right ventricular failure, pulmonary hypertension, or pre-existing pulmonary disease were excluded. The patients were randomly assigned to one of the following three groups: Group 1 (n = 10): static pulmonary inflation during ECC, PEEP 5-10 cm H2O, F1O2 1.0; Group 2 (n = 10): low-frequency ventilation during ECC, rate 10/min, PEEP 5 cm 5H2O, F1O2 1.0; Group 3 (n = 10): medium-frequency ventilation during ECC, rate 120/min, PEEP 5 cm 5H2O, F1O2 1.0. The measurements were made under relative steady-state conditions before the start of surgery and postoperatively after an equilibrium phase of at least 15 min. During ECC using a bubble oxygenator (Bentley BOS 10 S) in moderate hypothermia, blood was aspirated from the pulmonary artery during inflation of the wedge balloon and blood gases were analyzed. Postoperative changes in pulmonary function were evaluated by venous admixture (QVA/Qt); changes in pulmonary vascular resistance after ECC were determined using the pulmonary pressure-flow relationship. RESULTS. In group 1, QVA/Qt rose significantly from 9.6 +/- 2.9% preoperatively to 13.6 +/- 3.5% postoperatively (P less than 0.05, t-test for paired samples). In groups 2 and 3, postoperative QVA/Qt was significantly lower than preoperative QVA/Qt (P less than 0.05; group 2: preoperative 11.9 +/- 3.5%, postoperative 8.1 +/- 2.6%; group 3: preoperative 11.9 +/- 3.0%, postoperative 7.8 +/- 3.2%; Fig. 1). The postoperative pulmonary pressure-flow relationship changed similarly in all three groups (Fig. 2). During ECC, blood aspirated from the pulmonary artery during inflation of the wedge balloon was fully oxygenated with a hematocrit approximating that of arterial blood. In ventilated patients, pO2 during ECC was higher in pulmonary arterial blood than in arterial blood. Pulmonary ventilation during ECC did not lead to pulmonary arterial alkalosis. CONCLUSIONS. Pulmonary ventilation during ECC can prevent a post-operative increase in venous admixture. ECC-related pulmonary vascular changes were not affected by ventilation. Middle-frequency ventilation offers no advantage over low-frequency ventilation during ECC, except that the operating field is more quiet.     

Postoperative changes in blood flow in free muscle flaps: a prospective study.

We used color Doppler ultrasound (US) to study postoperative changes in blood flow in 10 non-innervated free latissimus dorsi (LD) muscle flaps transplanted onto lower extremities. The peak, mean, and minimum velocities, resistance index, and diameter of the pedicle, and the recipient and control arteries were recorded preoperatively and on the 2nd, 5th, and 10th days after surgery. In the pedicle of the transplant, the peak and mean velocities increased but not significantly during the follow-up. The minimum velocity value in the thoraco-dorsal artery was (mean+/-SD) 4+/-5 cm/sec preoperatively, and was in the leg 19+/-9 cm/sec (P < 0.05) on the 5th and 17+/-10 cm/sec (P < 0.05) on the 10th postoperative day. The preoperative value of the resistance index decreased from 0.92+/-0.12 to 0.79+/-0.08 on the 10th postoperative day (P < 0.05). In the recipient artery, the peak (117+/-37) and mean (35+/-16 cm/sec) velocities increased significantly on the 5th postoperative day compared to the preoperative value (79+/-22 and 14+/-6 cm/sec, respectively). The minimum velocity increased but not significantly. The resistance index was preoperatively 1.23+/-0.09 and 0.88+/-0.16 (P < 0.05) on the 10th postoperative day. This prospective clinical study demonstrates that blood flow in the pedicle and in the recipient artery of a free muscle flap increases after surgery. This phenomenon may be due to loss of vascular tone and decreased resistance after denervation. Increased blood flow helps to keep the microanastomosis open and also promotes wound healing.     

A retrospective study to compare the treatment outcomes with and without surgical navigation for fracture of the orbital wall

Purpose To evaluate the outcomes with and without aid of a computer-assisted surgical navigation system(CASNS)for treatment of unilateral orbital wall fracture(OWF).Methods Patients who came to our hospital for repairing unilateral traumatic OWF from 2014 to 2017 were included in this study.The patients were divided into the navigation group who accepted orbital wall reconstruction aided by CASNS and the conventional group.We evaluated the surgical precision in the navigation group by analyzing the difference between actual postoperative computed tomography data and preoperative virtual surgical plan through color order ratios.We also compared the duration of surgery,enophthalmos correction,restoration of orbital volumes,and improvement of clinical symptoms in both groups systemically.Quantitative data were presented as mean±SD.Significance was determined by the two-sample t-test using SPSS Version 19.0 A p<0.05 was considered statistically significant.Results Seventy patients with unilateral OWF were included in the study cohort.The mean difference between preoperative virtual planning and actual reconstruction outcome was(0.869±0.472)mm,which means the reconstruction result could match the navigation planning accurately.The mean duration of surgery in the navigation group was shorter than it is in the control group,but not significantly.Discrepancies between the reconstructed and unaffected orbital-cavity volume and eyeball projection in the navigation group were significantly less than that in the conventional group.One patient had remnant diplopia and two patients had enophthalmos after surgery in the navigation group;two patients had postoperative diplopia and four patients had postoperative enophthalmos in the conventional group.Conclusion Compare with the conventional treatment for OWF,the use of CASNS can provide a significantly better surgical precision,greater improvements in orbital-cavity volume and eyeball projection,and better clinical results,without increasing the duration of surgery.     

Preoperative and postoperative right ventricular function during exercise in patients with mitral stenosis.

To elucidate the effects of mitral valve surgery on right ventricular function in 11 patients with mitral stenosis, pre- and postoperative right ventricular function were quantified using gated equilibrium blood pool radionuclide ventriculography at rest and during exercise. The preoperative right ventricular ejection fraction was 39 +/- 4% at rest and 36 +/- 9% during exercise, which during exercise was lower than control values (51 +/- 5%) (p < 0.01). When the preoperative right ventricular ejection fraction was lower during exercise than at rest, postoperative right ventricular ejection fraction during exercise was lower than normal values (42 +/- 3% versus 51 +/- 5%) (p < 0.01). When the preoperative right ventricular ejection fraction did not decrease during exercise, the postoperative right ventricular ejection fraction was within normal limits during exercise (54 +/- 5%). In addition, postoperative right ventricular ejection fraction during exercise increased to normal values in patients whose preoperative right ventricular ejection fraction during exercise had been 40% or higher. Preoperative peak ejection rate was -1.81 +/- 0.19 EDV/sec at rest and -1.72 +/- 0.39 EDV/sec during exercise, which during exercise was lower than control values (-2.44 +/- 0.53 EDV/sec) (p < 0.01). Postoperatively, peak ejection rate during exercise (-2.50 +/- 0.37 EDV/sec) increased (p < 0.05) to normal levels. Preoperative peak filling rate was 1.61 +/- 0.47 EDV/sec at rest and 1.88 +/- 0.54 EDV/sec during exercise, which during exercise was lower than control values (2.58 +/- 0.62 EDV/sec) (p < 0.01). Postoperatively, peak filling rate during exercise (2.82 +/- 0.62 EDV/sec) increased (p < 0.05) to normal values in all patients. Preoperative changes in both right ventricular ejection fraction and peak ejection rate from rest to exercise inversely correlated with the preoperative pulmonary vascular resistance at rest (right ventricular ejection fraction, r = -0.79, p < 0.005; and peak ejection rate, r = -0.67, p < 0.05). In conclusion, right ventricular systolic function improved in about half of the patients with mitral stenosis, and diastolic function improved in all patients during exercise following surgery. When the preoperative pulmonary vascular resistance was elevated, the right ventricular systolic dysfunction persisted.     

Urodynamics in prostatism. I. Prognostic value of uroflowmetry

A prospective study was undertaken to examine the prognostic value for the symptomatic outcome of prostatic surgery of preoperative urodynamic testing in patients with prostatism. The study design included selection of patients for prostatic surgery by means of classic non-urodynamic urologic investigations such as history, residual urine, serum creatinine, cystoscopy and possibly intravenous urography. In addition an extensive urodynamic work-up (uroflowmetry, cystometry and pressure-flow study with stop-test) was included. The results of the urodynamic studies were unknown to the surgeon selecting the patients for operation. This evaluation was repeated 6 months postoperatively. Totally 139 patients entered the study. The patients were classified according to the preoperative maximum flow rate (Qmax) and in spite of preoperative differences in uroflow, pressure-flow variables and symptom scores, no differences of clinical significance were noted postoperatively among the groups. However, the high-flow group (preoperative Qmax greater than or equal to 15 ml/sec) had a statistically significant lower success rate as judged by the patients subjective evaluation of the outcome of surgery. An analysis of diagnostic sensitivity and specificity indicated Qmax = 15 ml/sec as a relevant cut-off value regarding preoperative identification of patients at risk of a less favourable outcome of surgery. This group of patients was characterized by a higher incidence of persistent uninhibited detrusor contractions at follow-up and a lower incidence of preoperative infravesical obstruction. In conclusion we recommend uroflowmetry in the preoperative evaluation of patients with prostatism.     

Lidocaine and increased respiratory resistance produced by ultrasonic aerosols.

Respiratory resistance significantly increased from 5.0 to 8.0 cm H2O/1/sec in anesthetized patients who were given ultrasonically nebulized water for 20 minutes via an endotracheal tube. Intravenous administration of lidocaine failed to reverse the provoked increase in resistance. In another group, respiratory resistance significantly increased from 5.8 to 7.5 cm H2O/1/sec in response to nebulized water despite prior and con-current intravenous administration of lidocaine. In a third group, initial respiratory resistance was 5.6 cm H2O/1/sec and did not increase during a 20-minute challenge with intratracheally administrered ultrasonically nebulized 2 per cent lidocaine. In a final group, resistance was increased from 5.0 to 6.9 cm H2O/1/sec with nebulized water. When challenge was continued with nebulized 2 per cent lidocaine, resistance remained elevated for about 10-12 minutes. It then decreased and returned to its initial control value at about 17 minutes, despite continuing lidocaine aerosol administration. Lidocaine, when administered intratracheally as an aerosol, both prevented and reversed provoked increases in respiratory resistance. Intravenously administered lidocaine was ineffective. Intratracheal administration of ultrasonically nebulized lidocaine might be another useful technique for management of bronchoconstriction in anesthetized patients.     

The male sling for stress urinary incontinence: urodynamic and subjective assessment

PURPOSE: We prospectively examined whether the fixed urethral resistance of the perineal male sling for the treatment of stress incontinence causes significant bladder outlet obstruction or de novo voiding dysfunction. MATERIALS AND METHODS: A total of 22 patients (average age 67 years old) were evaluated before and after surgery with videourodynamics, the self-administered UCLA Prostate Cancer Index incontinence section and pad score. RESULTS: Mean followup was 25 months (range 6 to 42). All patients complained of a moderate to severe problem before surgery. After surgery 16 (73%) reported a very small problem/no problem, 3 (14%) a moderate problem and 3 (14%) reported a big problem. Average pad use +/- SD decreased from 4.6 +/- 2.5 to 0.74 +/- 1.0 pads (p <0.01). Median UCLA Prostate Cancer Index incontinence score increased from 82 to 313, p <0.001. Mean retrograde leak point pressure (RLPP) increased from 30.4 +/- 15.9 to 59.9 +/- 9.7 cm water. Bladder outlet obstruction did not develop in any patients after surgery. Average maximum flow rate did not change significantly (17.7 +/- 6.5 vs 19.2 +/- 9.7 ml per second, p = 0.6). Nor was there a significant change in detrusor pressure at maximum flow rate (40.3 +/- 9.2 vs 45.8 +/- 14.7 cm water, p = 0.3). While de novo urgency or urge incontinence did not develop in any patients, 2 of 5 patients with a moderate/big leakage problem demonstrated postoperative detrusor overactivity on cystometry. Both individuals requiring more than 3 pads daily had a postoperative RLPP of less than 50 cm water. CONCLUSIONS: Pad use, leak point pressure and urinary incontinence scores are significantly improved after sling surgery. Fixed resistance does not lead to bladder outlet obstruction. Postoperative RLPP less than 50 cm water and urodynamic detrusor overactivity are associated with increased pad use and bother.     

Effects of intermaxillary fixation during orthognathic surgery on respiratory function after general anesthesia.

I examined the relationship between preoperative breathing route (nasal and/or oral) and respiratory status in 29 patients who underwent orthognathic surgery and intermaxillary fixation (IMF) with general anesthesia and in 14 healthy, adult control volunteers who received IMF without surgery or anesthesia. The tidal volume (VT), minute respiratory volume (MV), respiratory rate, and end-tidal carbon dioxide concentration were measured for both nasal and oral breathing before and after IMF. Pulse oximetry recordings were also taken. There was no significant effect of IMF on any parameter in the volunteers. Fifteen patients engaged in nasal breathing only both before and after surgery with IMF (group pN), and 7 patients had combined nasal and oral breathing before but only nasal breathing after IMF (group pNO). VT and MV decreased (536-357 mL and 7.84-5.40 L, respectively) in group pNO after IMF. These results suggest that assessment of the preoperative breathing status is helpful in predicting postoperative respiratory function after IMF and indicate that patients with preoperative mouth breathing require greater respiratory care after general anesthesia with IMF.     

Iron chelation therapy and lung transplantation. Effects of deferoxamine on lung preservation in canine single lung transplantation

Reperfusion injury is a limiting factor in lung transplantation. Deferoxamine is an iron chelator that inhibits the formation of oxygen-derived free radicals. We investigated the effects of deferoxamine on posttransplantation lung function in a canine model of single lung transplantation. Twelve dogs underwent left lung transplantation after 20- to 24-hour hypothermic storage in a modified Euro-Collins solution. In six experiments donor and recipient received a 10 mg/kg dose of deferoxamine before harvest and transplantation, and 10 mg/kg was added to the preservation solution. Arterial oxygen tension, alveolar-arterial oxygen difference, pulmonary vascular resistance, and dynamic lung compliance were measured. Data were recorded for 6 hours after ligation of the native pulmonary artery. At the end of the study the mean arterial oxygen tension was 175.1 mm Hg for the deferoxamine treated group versus 71.1 mm Hg for the control group (p less than 0.001), and the alveolar-arterial oxygen difference was less in the deferoxamine-treated group: 502.3 versus 606.0 mm Hg (p less than 0.001). The mean pulmonary vascular resistance was lower throughout the study, and after 6 hours it was 455.1 dynes/sec/cm(-5) in the deferoxamine-treated group versus 663.7 dynes/sec/cm(-5) in the control group (p less than 0.035). Compliance was similar in both groups. We conclude that deferoxamine improves lung preservation and early posttransplantation function in canine single lung transplantation.     

Compliance and functional residual capacity after staple versus combined staple/holmium laser lung volume reduction surgery in a rabbit emphysema model.

BACKGROUND: There is some evidence to suggest that laser exposure, when added to standard staple reduction techniques, may result in improved physiologic response to lung volume reduction surgery (LVRS). In this study, we compared physiologic responses of staple LVRS with combined staple/laser in a rabbit emphysema model. METHODS: Ninety-three New Zealand White rabbits underwent emphysema induction with aerosolized elastase 4 weeks before surgery and were killed 1 week after surgery. Treatment groups were bilateral moderate volume staple LVRS (< or =3 g, n = 39), combined moderate volume staple (< or =3 g)/holmium laser LVRS (n = 18), large-volume staple LVRS (> or =3 g, n = 27), or sham surgery (n = 9). RESULTS: Decrease in postoperative static respiratory system compliance by combined moderate-volume staple/laser treatment (1.22 cc/cm H2O) was similar to large-volume staple resection (1.40 cc/cm H2O, p = 0.39), and superior to moderate staple resection (0.82 cc/cm H2O, p = 0.01) or sham surgery (0.09 cc/cm H2O, p = 0.0001). Functional residual capacity decrease was greater after combined moderate staple/laser resection (6.46 cc) than large-volume staple resection (4.52 cc, p = 0.33), moderate-volume staple resection (4.59 cc, p = 0.43), or sham surgery (4.10 cc, p = 0.29). Perioperative mortality was highest after laser/staple LVRS (22%, 4/18). CONCLUSIONS: In this rabbit model, combined staple/ holmium laser reduction for emphysema results in significant improvement in compliance and trends toward improvement in functional residual capacity above staple reduction alone, but with higher mortality.     

Acute hemodynamic alterations after aortic valve replacement with the glutaraldehyde-treated porcine heterograft prosthesis

Twenty-two patients underwent aortic valve replacement for acquired valvular heart disease with the porcine heterograft prosthesis. In the immediate postoperative period, a transient decrease in the cardiac index (CI) (preoperative 3.0 +/- 0.14 to 2.45 +/- 0.16 L. per minute per square meter, p less than 0.05) and an increase in the systemic vascular resistance (SVR) (preoperative 1,078 +/- 62 to 1,287 +/- 103) dynes/sec./cm.-5, p greater 0.05) were seen; these values returned to preoperative levels by the first postoperative day. After valve replacement, an elevation in the heart rate (HR) (preoperative 75 +/- 2 to 87 +/- 4 beats per minute, p less than 0.05) and a reduction in the stroke volume (SV) and stroke work index (SWI) (preoperative 35 +/- 2 to 26 +/- 2 Gm.-M. per square meter, p less than 0.05) occurred which persisted throughout the study. The endocardial viability ration (EVR) increased after valve replacement. These findings suggest that, following aortic valve replacement, (1) an increase HR is the mechanism utilized to maintain cardiac output, (2) subendocardial perfusion is enhanced as indicated by an increase in the EVR, and (3) the hemodynamic alterations following insertion of the porcine heterograft prosthesis are not different from those observed when other valves are placed in similar patient populations.     

Clinical assessment of unilateral pulmonary artery occlusion test with dobutamine infusion. Expansion of surgical indications in patients with primary lung cancer and impaired cardiopulmonary functions.

OBJECTIVES: We evaluated the possibility of expanding indications for pulmonary resection based on an assessment of the pressure-flow relationship in pulmonary circulation. METHODS: In 6 of 28 lung cancer patients whose total pulmonary vascular resistance index exceeded the threshold during unilateral pulmonary artery occlusion testing, we conducted unilateral pulmonary artery occlusion testing with dobutamine administration, followed by lung resection. We studied hemodynamics during testing and derived a new indication for pulmonary resection from the postoperative course. RESULTS: Cardiac output was 3.82 +/- 0.74 l/min before testing, 3.66 +/- 0.76 l/min during pulmonary artery occlusion testing, and 5.92 +/- 1.78 l/min during unilateral pulmonary artery occlusion testing with dobutamine infusion. The total pulmonary vascular resistance index was 890 +/- 350 dyne.sec.cm-5.m2 before testing, 1170 +/- 320 dyne.sec.cm-5.m2 during testing, and 800 +/- 160 dyne.sec.cm-5.m2 during testing with dobutamine infusion. Cardiac output increased (p = 0.014) during unilateral pulmonary artery occlusion testing with dobutamine infusion, and the total pulmonary vascular resistance index significantly decreased (p = 0.034). Of the 4 patients eligible for lobectomy, 2 underwent the procedure--one undergoing segmentectomy in which pulmonary metastasis was found during surgery and the other undergoing radiotherapy for cN2 disease with chest wall invasion. Of the 2 initially ineligible for lobectomy, one underwent partial pulmonary resection and the other underwent lobectomy because the total pulmonary vascular resistance index was less than 800 dyne.sec.cm-5.m2 during selective pulmonary artery occlusion testing with dobutamine infusion, indicating eligibility for lobectomy. No severe complications of cardiopulmonary function failure after surgery occurred in any of the 5 cases. CONCLUSIONS: Unilateral pulmonary artery occlusion testing with dobutamine infusion is useful in determining patient eligibility for pulmonary resection.     

The value of posterior levator repair in the treatment of anorectal incontinence due to rectal prolapse – a clinical and manometric study

BACKGROUND: When treating a complete rectal prolapse, the most important objective is elimination of the prolapse. In addition, restoration of sufficient anorectal continence is extremely important for the patients. We examined the value of posterior levator repair with respect to stabilization of the pelvic floor and to improvement in anorectal incontinence. METHODS: In patients with disabling anorectal incontinence, a posterior levatorplasty can be concomitantly performed during operative removal of the prolapse. To facilitate evaluation of the operative results, we implemented a scoring system to judge the patients' subjective symptoms of incontinence; in addition, we performed manometric measurements of resting and squeezing pressures of the anal sphincter to objectify the anorectal incontinence. RESULTS: From 1991 to 1997, 84 patients (mean age 65+/-10 years, 38-91 years; 79 women, 5 men) with complete rectal prolapse and severe incontinence were operatively treated; corresponding follow-ups were done. The following procedures were performed: Frykmann-Goldberg, 28 patients; Wells, 18 patients; Ripstein, 22 patients; and perineal proctectomy, 16 patients. Incontinence for liquid and solid stools was present in all of these patients. Posterior levatorplasty was implemented in 38 patients, and in this group we found significantly better postoperative results, both clinically and in the manometric measurements. Continence was improved by 84% in the group with levatorplasty, but improvement was only 67% in the other group (P<0.05). The incontinence score decreased significantly in the group with levatorplasty (preoperative 16.4+/-3.1, postoperative 9.3+/-4.5, P<0.05, vs the other group with preoperative 15.6+/-4.2, postoperative 11.5+/-5.1). Manometric observations in the group with levatorplasty demonstrated 55% improvement in resting pressure (preoperative 29+/-17 cm H2O, postoperative 45+/-21 cm H2O, P<0.05) and 40% improvement in squeezing pressure (preoperative 61+/-25 cm H2O, postoperative 85+/-31 cm H2O, P<0.05). In the group without levatorplasty, resting and squeezing pressure improved only by 20% (resting pressure: preoperative 32+/-16 cm H2O, postoperative 38+/-18 cm H2O; squeezing pressure: preoperative 64+/-29 cm H2O, postoperative 75+/-26 cm H2O). CONCLUSIONS: Posterior levatorplasty is an easy and efficient operative procedure which facilitates an improvement in anorectal continence. There are no apparent disadvantages. For this reason, levatorplasty can be part of operative procedures implemented in the treatment of a complete rectal prolapse accompanied by disabling anorectal incontinence.