Robotic arm-assisted versus conventional medial unicompartmental knee arthroplasty: five-year clinical outcomes of a randomized controlled trial.

AIMS: Unicompartmental knee arthroplasty (UKA) is a bone-preserving treatment option for osteoarthritis localized to a single compartment in the knee. The success of the procedure is sensitive to patient selection and alignment errors. Robotic arm-assisted UKA provides technological assistance to intraoperative bony resection accuracy, which is thought to improve ligament balancing. This paper presents the five-year outcomes of a comparison between manual and robotically assisted UKAs. METHODS: The trial design was a prospective, randomized, parallel, single-centre study comparing surgical alignment in patients undergoing UKA for the treatment of medial compartment osteoarthritis (ISRCTN77119437). Participants underwent surgery using either robotic arm-assisted surgery or conventional manual instrumentation. The primary outcome measure (surgical accuracy) has previously been reported, and, along with secondary outcomes, were collected at one-, two-, and five-year timepoints. Analysis of five-year results and longitudinal analysis for all timepoints was performed to compare the two groups. RESULTS: Overall, 104 (80%) patients of the original 130 who received surgery were available at five years (55 robotic, 49 manual). Both procedures reported successful results over all outcomes. At five years, there were no statistical differences between the groups in any of the patient reported or clinical outcomes. There was a lower reintervention rate in the robotic arm-assisted group with 0% requiring further surgery compared with six (9%) of the manual group requiring additional surgical intervention (p < 0.001). CONCLUSION: This study has shown excellent clinical outcomes in both groups with no statistical or clinical differences in the patient-reported outcome measures. The notable difference was the lower reintervention rate at five years for roboticarm-assisted UKA when compared with a manual approach. Cite this article: Bone Joint J 2021;103-B(6):1088-1095.

Diagnosis of cytomegalovirus pneumonia in compromised hosts.

Sixteen patients with cytomegalovirus pulmonary infection are described. In 11 the diagnosis was made antemortem by lung aspirate or biopsy, and in five the diagnosis was made at postmortem by typical lung histology and positive viral lung cultures. All patients were immunosuppressed by both their underlying diseases and treatment with corticosteroids and other chemotherapy. Although other pathogens were identified at lung biopsy in most patients (73 per cent), primarily Pneumocystis carinii, evidence is offered to demonstrate that cytomegalovirus can cause significant pulmonary disease alone, leading to respiratory failure and death.

Open lung biopsy in patients with acute leukemia.

The results of open lung biopsy in 15 patients with acute leukemia, pulmonary infiltrates, neutropenia, and fever were reviewed. The patients averaged 26 hospital days of neutropenia and 20 hospital days of fever before open lung biopsy, and all patients received broad-spectrum antibacterial agents (mean 17 days) before open lung biopsy. Nine (67 percent) received amphotericin B prior to open lung biopsy (mean 22 days). Open lung biopsy yielded a specific clinically helpful diagnosis in six patients, but only two of these patients survived the hospitalization during which open lung biopsy was performed. Open lung biopsy detected fungus in four patients and leukemic infiltrates in two patients. Management was appropriately modified in these patients. In nine patients, a specific diagnosis of the pulmonary infiltrate was not obtained by open lung biopsy. Antimicrobial regimens were not changed substantially for these patients. In six patients, the results of open lung biopsy may have been misleading. Two patients had pulmonary fungal diseases at autopsy, undetected by open lung biopsy eight days and five weeks prior to death. Another patient had invasive aspergillosis and one had cytomegalovirus pneumonitis not detected by open lung biopsy. Two patients had false-positive preliminary histologic reports of pulmonary infection. On the basis of this experience, in this specific population of patients, open lung biopsy was often of little help in directing medical therapy or influencing clinical outcome.

A new catheter system with remote tip guidance for endobronchial brachytherapy.

Endobronchial brachytherapy is being used with increased frequency in the treatment of recurrent neoplastic obstruction of the major airways, alone or in combination with Nd-YAG laser ablation of the occluding tumor mass. Currently available catheter systems are not reliable with respect to accurate and simple bronchoscopic guidance during placement. Flexibility, wall strength and radiation transmission characteristics are not optimized. We describe a system that meets these goals which has been designed and tested in our department. It is composed of an external handle, deflecting guidewire, and catheter specially modified for endobronchial brachytherapy, with a tip that can be maneuvered in any direction with one hand from outside the patient. Major advantages of the system are ease of concurrent bronchoscopy and catheter guidance, good dosimetric characteristics of the catheter, reasonable cost, and ready availability for adaptation to various techniques of endobronchial brachytherapy.

Localization of bronchopleural fistula using ventilation scintigraphy.

It can be difficult to localize or even lateralize the site of persistent bronchopleural fistula in patients who have undergone thoracotomy. If the site of persistent air leak can be identified noninvasively, it may be possible to repair the leak with thoracoscopic techniques and thereby avoid repeat thoracotomy. This article reports experience using 99mTc-DTPA ventilation scintigraphy to localize persistent bronchopleural fistulas in six patients. The site of bronchopleural fistula was identified in four patients. In the other two patients, no leak was identified, and the clinical course confirmed that a significant bronchopleural fistula did not exist.

Diagnosis and localization of bronchopulmonary air leaks using ventilation scintigraphy.

STUDY OBJECTIVES: To determine the usefulness of radioaerosol ventilation scans for the detection and localization of air leaks from the lungs or bronchial tree. DESIGN: Selected patients with suspected air leaks underwent ventilation scans. Retrospective analysis of data was carried out. SETTING AND PATIENTS: Twenty-eight hospitalized patients were included in the study. INTERVENTIONS: Ventilation scintigraphy using 99mTc-DTPA (technetium aerosol) was carried out in patients with air leaks. MEASUREMENTS AND RESULTS: Of the total group, there were 50% true-positive scans, 36% true-negative scans, and 14% false-negative scans giving a sensitivity of 78%, specificity of 100%, and accuracy of 86%. CONCLUSIONS: 99mTc-DTPA ventilation scintigraphy is useful in some patients with air leaks from the lung or tracheobronchial tree and may help to guide surgical intervention should this become necessary.

Bronchoscopic diagnosis and treatment of bronchial stump suture granulomas.

Eight patients in whom new respiratory symptoms developed following pulmonary resection have been evaluated. The bronchial stumps in all of these patients had been closed with Tevdec suture material. The total number of pulmonary resections using Tevdec suture from January, 1971, to January, 1980, was 180, yielding an incidence of the complication of 4.4%. No patient had empyema or bronchopleural fistula. Symptoms included nonproductive cough (eight patients), hemoptysis (five patients), wheezing (two patients), and coughing up suture material (two patients). The underlying disease necessitating pulmonary resection was carcinoma in five patients, carcinoid adenoma in one patient, tuberculosis in one patient, and bronchiectasis in one patient. The median time interval between resection and development of respiratory symptoms was 18 months, with a range of 8 to 57 months. The chest roentgenograms showed no change from earlier postoperative films. Bronchoscopy under general anesthesia was performed in all eight patients. Granulation tissue around loosened Tevdec sutures was present in all patients so examined. No residual tumor or specific infection was identified. Immediate and sustained relief of symptoms was obtained in seven of eight patients by removal of the loosened sutures. One patient has had recurrence of minor hemoptysis 18 months following suture removal but has refused further endoscopy. Stainless steel staples have been used for bronchial stump closure in over 100 pulmonary resections since 1977 and no such complications have been seen.

Treatment of bronchopleural fistula after pneumonectomy.

Breakdown of the closure of the main-stem bronchus after pneumonectomy is a dreaded complication, and empyema and bronchopleural fistula frequently develop in patients who survive. Management of these fistulas remains a formidable therapeutic challenge, which has been approached with a variety of surgical techniques. We report our experience with anterior transpericardial closure, emphasizing the ability to expose either main-stem bronchus by this approach. The case histories of three patients who had bronchopleural fistula after pneumonectomy are presented. The first patient had left pneumonectomy for complicated tuberculosis; the second had right pneumonectomy for neoplasm; and the third had right pneumonectomy for trauma. All fistulas were treated surgically via a median sternotomy and transpericardial approach to the distal trachea. The posterior pericardium was divided between the superior vena cava and aorta. In-continuity staple closure (with two lines of staples) of the proximal main-stem bronchus was employed in all cases. Two patients remain clinically well 21 and 17 months after the operation. The third patients did well initially but developed a recurrent bronchopleural fistula 2 1/2 months after the operation and has required repeat closure with pedicled muscle flaps. In postpneumonectomy bronchopleural fistula, the anterior, transpericardial approach to bronchial closure has several advantages: the relatively well-tolerated median sternotomy, the avoidance of dealing directly with areas of postoperative scarring and the devascularized bronchial stump, the avoidance of areas of chronic sepsis, and the avoidance of thoracoplastic surgical deformity of the chest wall, with possible associated compromise in pulmonary function. Our experience also indicates that either main-stem bronchus is accessible through an approach between the superior vena cava and aorta, without division of either pulmonary artery.

Pulmonary resection in children with metastatic osteogenic sarcoma: improved survival with surgery, chemotherapy, and irradiation.

Twelve consecutive unselected patients (aged 6 to 18 years) with osteogenic sarcoma underwent 19 thoracotomies for resection of pulmonary metastases. Wedge excisions of 41 metastatic nodules, one bilobectomy, and one pneumonectomy were performed. Six patients each required one thoracotomy, five patients underwent two thoracotomies, and one patient required three. Serious surgical complications were limited to one patient who required reoperation for closure of a bronchopleural fistula following bilobectomy. Initial pulmonary metastasis occurred 9 months (mean) after amputation (range 1 to 21 months). Complete excision of all identifiable metastatic tumor was possible in 17 of 19 thoracotomies. All patients received intensive cyclical chemotherapy after initial definitive amputation, after thoracotomy, or both. Tumor doubling time (TDT) during chemotherapy (mean 74 days) was significantly prolonged (p = 0.017) compared to TDT during intervals of no therapy (mean 22 days). Five patients received pulmonary radiotherapy prior to thoracotomy and five after thoracotomy. Four patients died during the observation period, having survived 10 to 30 months after amputation. Two patients are alive with known extrapulmonary metastases. Six patients are free of disease. The survival rate is 91.7 percent 1 year after amputation, 82.5 percent at 2 years, and 57.8 percent at 3 years. These results suggest improved survival when aggressive surgical resections of pulmonary metastases are combined with chemotherapy and radiotherapy. Thoracic surgical procedures in this group of patients are safe and associated with a low incidence of complications despite the potentially increased risks owing to antecedent chemotherapy and pulmonary irradiation.

The role of bronchoscopy and needle aspiration in the diagnosis of peripheral lung masses.

Sixty patients underwent flexible fiberoptic bronchoscopy and percutaneous needle aspiration of peripheral lung lesions with fluoroscopic monitoring. A single general anesthetic was used. We found that percutaneous needle aspiration was the more accurate of the two procedures in establishing a diagnosis but that flexible fiberoptic bronchoscopy proved complementary in some instances. The incidence of pneumothorax was 27% but aspiration was needed in only 8%. There were no other complications. In 84% of patients with primary carcinoma of the lung presenting as a peripheral lesion, the diagnosis was established by these procedures. The accuracy was less in metastatic lesions and considerably less in benign lesions.

Lye ingestion. Clinical patterns and therapeutic implications.

Conventional treatment of caustic esophagitis consists of early endoscopy to the first site of injury followed by antibiotic and steroid therapy, with early mechanical dilatation to prevent stricture formation. The failure of this approach in two recent patients led us to review our overall experience with the management of patients who had ingested lye or other caustic substances. Of 42 patients treated at the Santa Clara Valley Medical Center between 1970 and 1980, seven sustained severe esophageal burns. All had intractable strictures despite steroids, antibiotics, and, in three cases, attempts at dilatation. We conclude that patient survival should not be jeopardized by overly aggressive attempts to salvage an extensively damaged esophagus. Such attempts will probably prove both futile and dangerous, and effective re-establishment of oral-intestinal continuity is now possible by a variety of techniques.

Therapeutic thoracoscopy.

Thoracoscopy was originally devised for diagnostic purposes but has subsequently come to have several therapeutic applications as well. This report reviews our experience with 13 patients in whom thoracoscopy was used in a therapeutic capacity. In three patients intrapleural foreign bodies (segments of polyethylene catheters) were removed endoscopically. In two patients open postpneumonectomy empyema cavities were explored and debrided thoracoscopically. In the remaining eight patients thoracoscopy was used to facilitate chemical pleurodesis in the treatment of effusions or pneumothoraces, after resectable disease had first been ruled out. Our conclusions are as follows: (1) Thoracoscopy can serve therapeutic as well as diagnostic functions. (2) Excellent exposure can be obtained during general anesthesia by use of one-lung ventilation. (3) Thoracoscopy is a safe, simple, and effective means of removing intrapleural foreign bodies. (4) Thoracoscopy allows chemical pleurodesis to be applied selectively to patients who will not require future thoracotomy; i.e., those with proved incurable malignant disease or with recurrent pneumothoraces without gross abnormalities of the pulmonary parenchyma. (5) Chemical pleurodesis is facilitated by this technique, which assures uniform exposure of all pleural surfaces to the sclerosing agent. (6) Pleurodesis is less painful when the sclerosing agent is introduced during general anesthesia. (7) Thoracoscopy allows safe, complete, visually guided débridement of open postpneumonectomy empyema cavities.

Recurrent mediastinal bronchogenic cyst. Cause of bronchial obstruction and compression of superior vena cava and pulmonary artery.

The recurrence of a benign mediastinal bronchogenic cyst 20 years after partial excision precipitated potentially serious vascular and pulmonary complications. Aggressive total surgical excision should be feasible in the majority of cases. An approach via a median sternotomy offers distinct advantages in certain cases and should be considered. Computerized axial tomographic scanning promises to provide improved definition of mediastinal anatomic features and should be a valuable noninvasive diagnostic method in selected cases.

Flow reversal in the descending aorta: a guide to intraoperative assessment of aortic regurgitation with transesophageal echocardiography.

This study assessed the value of biplane transesophageal echocardiographic assessment of diastolic flow reversal in the descending aorta as an alternative to Doppler color flow imaging in determining severity of aortic regurgitation. In 45 patients undergoing cardiac operations, the severity of aortic regurgitation was assessed by semiquantitative grading of the width of the Doppler color flow regurgitant jet relative to the left ventricular outflow tract, and the presence of diastolic flow reversal was assessed with pulsed-wave Doppler measurements at three sites in the descending aorta. In four patients, the diastolic flow reversal method was the only available form of assessment because of inadequate visualization of the left ventricular outflow tract beneath a mitral valve prosthesis. Diastolic flow reversal in the descending aorta was not observed in patients without aortic regurgitation and was always present in patients with severe aortic regurgitation. Aortic valve replacement successfully eliminated descending aortic flow reversal in all 19 patients in whom it was present before valve replacement. Identification of diastolic flow reversal at multiple sites in the descending aorta with biplane transesophageal echocardiography helps to confirm the presence of severe aortic regurgitation and can serve as an alternative method of assessment when visualization of the left ventricular outflow tract is impaired.

Continuous arterial and venous blood gas monitoring during cardiopulmonary bypass.

A new monitoring technique, based on optical fluorescence chemistry, allows continuous monitoring of all blood gas variables during cardiopulmonary bypass. To evaluate the clinical performance of this monitor, we drew 220 arterial and 216 venous blood samples from 15 patients, and simultaneous blood gas values displayed by the monitor were compared with standard laboratory measurements. The continuous monitor predicted laboratory values with varying degrees of accuracy. (R2 values by linear regression: arterial oxygen tension 0.86, venous oxygen tension 0.36, arterial carbon dioxide tension 0.58, venous carbon dioxide tension 0.72, arterial pH 0.53, venous pH 0.58; pH 0.53, venous pH 0.58; p less than 0.0001). Monitor values of arterial oxygen tension overestimated laboratory values (bias = + 43.5 mm Hg), but the laboratory reference method likely underestimated true arterial oxygen tension in the high range achieved on bypass. Monitoring of venous oxygen tension was imprecise (precision = +/- 6.51 mmHg), regardless of whether stable conditions existed during the sampling period. Monitoring of carbon dioxide tension and pH showed small bias (carbon dioxide tension within 2 mm Hg, pH within 0.03) and good precision (carbon dioxide tension within 3 mm Hg, pH within 0.03). With the development of unstable conditions on bypass, monitor arterial oxygen tension values showed a changing relationship to corresponding laboratory values. In conclusion, arterial and venous carbon dioxide tension and pH monitoring provide acceptably accurate alternatives to laboratory measurement of these variables during cardiopulmonary bypass. Arterial oxygen tension monitoring accurately indicates changes in oxygen tension in the arterial oxygen tension range typically produced during extracorporeal circulation. Oxygen tension monitoring in the venous oxygen tension range is too imprecise for clinical decision-making purposes.

Bronchoscopy after cardiopulmonary transplantation.

Eighteen combined heart and lung transplant operations were performed between March, 1981, and March, 1984. Six of these patients have undergone bronchoscopy, at varying intervals after transplantation. Five of these procedures were done for specific clinical indications; one was done incidentally, during another surgical procedure requiring general anesthesia. All patients had intact, healing tracheal anastomotic suture lines; there were no instances of tracheal stenosis. The distal tracheobronchial tree appeared endoscopically normal in the transplanted lungs, except in areas of known infiltrates. Four of the patients had endobronchial biopsies, and alveolar eosinophilic proteinaceous exudate and submucosal mononuclear infiltrate were consistent features. Two of the later biopsies suggest that squamous metaplasia of the respiratory epithelium may occur with long-term follow-up. Controversy exists as to the optimal technique for tracheal anastomosis, but in the case of the steroid-treated, immunosuppressed transplant patient, continuous anastomosis with polypropylene has yielded satisfactory results.

The use of thoracoscopy in the diagnosis of pleural disease.

Seventeen patients (ten male and seven female) between the ages of 21 and 76 years underwent thoracoscopy from 1976 through 1978 by the Stanford University University Thoracic Surgical Service. There was no morbidity or mortality. This technique was used when other conventional methods such as thoracentesis and pleural biopsy failed to obtain a diagnosis of suspected thoracic pathology. Thoracoscopy was diagnostic in 16 of 17 cases. The diagnosis of malignancy was made in 11 cases, whereas benign disease was found in the remaining six cases. Of the latter group, there was one false-negative result, which on subsequent thoracotomy was diagnosed as recurrent Hodgkin's disease. The current revival of thoracoscopy as a diagnostic entity is proving to be very valuable in the evaluation of thoracic disease. An increased awareness of the tool and its use should decrease the number of major thoracotomy procedures.

Selection factors resulting in improved survival after surgical resection of tumors metastatic to the lungs.

From 1973 through 1987, a total of 140 patients underwent 184 operations for removal of metastatic tumors to the lungs. The number of lesions removed ranged form one to 30. Of the patients, 44% had solitary lesions. Overall 3-year survival was 62.6%, and 5-year survival was 48.2%. In all primary tumors except melanoma and breast cancer, 3-year survival was greater than 50% and 5-year survival was greater than 40%. With rare exceptions, the operation of choice for unilateral lesions was ipsilateral thoracotomy, and for bilateral lesions it was median sternotomy. Adequate conservative resection was the rule. There were three pneumonectomies, 25 lobectomies, 71 single wedge resections, 38 multiple unilateral wedge resections, and 47 bilateral wedge resections. There were no postoperative hospital deaths. Cox covariate analysis demonstrated improved survival in patients whose largest lesion was less than 1.5 cm in diameter and with disease-free interval longer than 1 year, but survival was not related to number of lesions or age of patient. An aggressive surgical approach is justified in patients with most primary tumors and a limited number of lung metastases less than 1.5 cm in diameter. Resection of metastases from melanoma and breast cancer should be accomplished after other sites of metastatic disease have been ruled out by the most stringent criteria.

Balloon method for detecting inadequate double-lumen tube cuff seal.

A method for detecting air leak when using a double-lumen endobronchial tube is described. The ventilatory circuit is directly attached to the lumen of the ventilated lung. A balloon is fitted snugly over the open lumen of the tube to the nonventilated lung. If lung separation is incomplete, the balloon will inflate with each ventilation.

Advantages of a new polyvinyl chloride double-lumen tube in thoracic surgery.

Double-lumen endobronchial tubes offer many advantages during thoracic operations. However, technical problems with tube placement and potentially life-threatening complications have discouraged widespread use of standard double-lumen tubes. Some of these problems may be reduced with a new polyvinyl chloride (PVC) double-lumen tube. A total of 214 intubations were undertaken in 204 patients using one of three endobronchial tubes. The cases of these patients were reviewed to determine differences in the complications associated with the Carlens, Robertshaw, and PVC tubes. Complications included unsuccessful or difficult intubation, tube dislodgment, unsatisfactory lung deflation, tube malposition, and hypoxemia. In 8 of 16 intubations with the Carlens tube and in 14 of 62 intubations with the Robertshaw tube, there were complications. In all, 22 of 78 intubations (28%) using conventional double-lumen tubes were complicated compared with 5 of 136 (4%) using the PVC tube. The technical problems and risks of endobronchial intubation were reduced significantly with the PVC double-lumen tube.