Experimental study of the participation of the vertebral endplate in the integration of bone grafts

The surgical technique of anterior vertebral arthrodesis has been modified by the introduction of cages in spinal surgery. The classical technique recommends removal of the vertebral endplate and exposure of bleeding cancellous bone. However, after the observation of cage subsidence during postoperative follow-up, the vertebral endplate is no longer removed, due to its greater mechanical resistance which can prevent cage subsidence. The mechanical characteristics of the vertebral endplate are well known, in contrast to its osteogenic potential, which was investigated in the present experimental study. The study was conducted on mongrel dogs of both sexes, which were submitted to anterior corpectomy at the cervical spine level. A cortico-cancellous bone graft removed from the tibia was used for the reconstruction of the vertebral segment, which was used with osteosynthesis plates. At the site of contact between the surface of the vertebral body and the bone graft, the vertebral endplate was completely removed and cancellous bone was exposed in the inferior vertebra, whereas in the superior vertebra of the arthrodesed vertebral segment only curettage was performed, and the vertebral endplate was preserved, as recommended for cage implantation. Twenty adult dogs of both sexes were divided into four experimental groups according to time of sacrifice (15, 30, 90, and 180 days). The consolidation of the bone graft with the vertebral body was evaluated by histology using hematoxilin-eosin and Gomori trichrome staining. In the interface between the bone graft and the vertebral body surface in which the vertebral endplate was not removed, graft consolidation was not observed in any of the group I animals (sacrificed after 15 days), and was observed in 1/5 animals of group II (30 days), in 2/5 animals of group III (90 days), and in 4/5 animals of group IV (180 days). In the interface between the graft and the vertebral body in which the vertebral endplate was removed, bone-graft consolidation was observed in all animals of all experimental groups (15, 30, 90, and 180 days). Bone-graft consolidation with the surface of the vertebral body was influenced by the removal or maintenance of the vertebral endplate. Due to the importance of this structure in current surgical procedures, this phenomenon deserves to be studied in more detail in order to understand the basic events involved in this process.Research carried out in the Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14048-900 Ribeirão Preto, SP, Brazil.     

Immunological and echocardiographic evaluation of decellularized versus cryopreserved allografts during the Ross operation.

OBJECTIVE: Compare the immunological and echocardiographic data of decellularized versus cryopreserved allografts used for RVOT reconstruction during Ross operation. METHODS: From 16/01/03 thru 07/10/03, 20 Ross operations were performed using decellularized (n=11) or cryopreserved (n=9) allografts. Echocardiography was done at discharge, 1, 3, 6 and 12 months and annually thereafter. Samples for determination of antibodies against HLA class I and II were obtained preoperatively and at days 5, 10, 30, 90 and 180 postoperatively. These samples were tested by the ELISA method in LAT-M dishes (unspecific) for identification of circulating antibodies and the results expressed as mean sample values (Is=DO/cutoff). If positive, LAT-E (specific) was performed and PRA levels determined. RESULTS: There was no mortality. Cryopreserved allografts showed marked Is values elevations for class I and II antibodies which started at the first month and remained elevated up to 6 months. In contrast, of the patients receiving decellularized allografts, seven remained negative, two patients had only marginal elevation of class I antibodies and two patients showed abnormal elevations of PRA levels. This response happened earlier than in the cryopreserved group, starting on the 5th postoperative day and has returned to baseline levels in one case. Echocardiography showed mild, but significant, elevation of gradients in cryopreserved valves but none in the decellularized. CONCLUSIONS: Decellularized allografts had normal function up to 18 months and showed important reduction of the immunogenic response when compared to cryopreserved valves.     

Risk factors for decreased total body and regional bone mineral density in hemodialysis patients with severe secondary hyperparathyroidism.

Hyperparathyroidism contributes significantly to decreased bone mineral density (BMD) in end-stage renal disease patients, but this negative influence is not homogeneous throughout the skeleton. We studied the BMD by dual-energy X-ray absorptiometry on total body and on different regions of the skeleton in 42 patients with severe hyperparathyroidism on hemodialysis. We also evaluated the relationship between different risk factors and BMD found on the regions examined in these patients. The legs and other sites where cortical bone predominate were mostly affected, whereas trabecular bone was relatively preserved. This is probably the result of the different effects of hyperparathyroidism on cortical and trabecular bone, but we cannot rule out the interference of ectopic calcifications and sclerotic lesions of vertebral end-plates falsely increasing lumbar spine BMD. The main determinants of low total-body BMD were, in order of importance, immobility, high intact parathyroid hormone levels, low body mass index, and low albumin. Eleven patients presented with pathologic fractures, mainly in the legs, and BMD was lower in this group than in patients without fractures. In conclusion, our study makes clear that hyperparathyroidism is a great threat to bone density in hemodialysis patients, mainly in the legs, the site mostly affected by fragility fractures in our patients. Physicians must worry not only with high parathyroid hormone levels, but also with the nutritional state of these patients.     

Redistribution of joint moments is associated with changed plantar pressure in diabetic polyneuropathy

Background  

Patients with diabetic polyneuropathy (DPN) are often confronted with ulceration of foot soles. Increased plantar pressure under the forefoot has been identified as a major risk factor for ulceration. This study sets out to test the hypothesis that changes in gait characteristics induced by DPN related muscle weakness are the origin of the elevated plantar pressures.     

A posterior-based omega-shaped flap vaginoplasty in girls with congenital adrenal hyperplasia caused by 21-hydroxylase deficiency

OBJECTIVE: To describe a technical modification for constructing a vagina in girls with congenital adrenal hyperplasia caused by 21-hydroxylase deficiency, using a narrower skin base but rich subcutaneous tissue, aiming to obtain both longer and larger vaginal segments with better cosmesis of the external genitalia. PATIENTS AND METHODS: From August 1997 to February 2001, 28 girls (aged 5 months to 17 years) had a neovagina constructed using a posterior-based omega-shaped flap. Twenty-six patients had a low vagina entering into the urogenital sinus and two had a high vagina that entered the urogenital sinus. In those with a high vagina the flap procedure was combined with the Passerini-Glazel technique. All the patients were scheduled for vaginal "calibrations" during the first year after surgery and, according to the result, would then undergo vaginal dilatation. RESULTS: Six children were re-operated; five had plastic surgery to correct genital folds that had regained a scrotal aspect, whereas one with a high vagina developed a urethral stricture, with urinary dribbling and infection, and had the urethra reconstructed. These six children are currently well. No hormone therapy was given to one child for 1 year who is scheduled for further surgery for a re-virilized clitoris. Two patients were lost to follow-up. Up to the last visit, 19 girls had not developed a vaginal stricture and the cosmesis of their external genitalia was deemed good. CONCLUSION: The posterior-based omega-shaped flap enabled both the construction of wider vaginal segments with a low risk of developing stenosis in those with a low vagina, and increased vaginal dimension when associated with the Passerini-Glazel technique for those with a high vagina. However, despite good cosmesis of the external genitalia, the follow-up is too short to confirm whether this technique will meet all the expectations.     

Evaluation of the influence of pulmonary hypertension in ultra-fast-track anesthesia technique in adult patients undergoing cardiac surgery

Objective

To evaluate the influence of pulmonary hypertension in the ultra-fast-track anesthesia technique in adult cardiac surgery.

Methods

A retrospective study. They were included 40 patients divided into two groups: GI (without pulmonary hypertension) and GII (with pulmonary hypertension). Based on data obtained by transthoracic echocardiography. We considered as the absence of pulmonary hypertension: a pulmonary artery systolic pressure (sPAP) <36 mmHg, with tricuspid regurgitation velocity <2.8 m/s and no additional echocardiographic signs of PH, and PH as presence: a sPAP >40 mmHg associated with additional echocardiographic signs of PH. It was established as influence of pulmonary hypertension: the impossibility of extubation in the operating room, the increase in the time interval for extubation and reintubation the first 24 hours postoperatively. Univariate and multivariate analyzes were performed when necessary. Considered significant a P value <0.05.

Results

The GI was composed of 21 patients and GII for 19. All patients (100%) were extubated in the operating room in a medium time interval of 17.58±8.06 min with a median of 18 min in GII and 17 min in GI. PH did not increase the time interval for extubation (P=0.397). It required reintubation of 2 patients in GII (5% of the total), without statistically significant as compared to GI (P=0.488).

Conclusion

In this study, pulmonary hypertension did not influence on ultra-fast-track anesthesia in adult cardiac surgery.     

Impact of Cold Ischemia Time on the Function of Liver Grafts Preserved With Custodiol

ObjectiveThis study aimed to evaluate how cold ischemia time (CIT) interferes with liver graft function in the first 7 days after surgery for Custodiol (HTK) preserved organs.MethodsThis retrospective observational study analyzed the medical records of 38 transplantation patients at Hospital Leforte Liberdade, São Paulo, in 2018. The study population was divided into 2 groups (group A, CIT < 8 hours; group B, CIT > 8 hours). Postoperative parameters—such as international normalized ratio, total bilirubin, aspartate aminotransferase/alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase (GGT), lactate dehydrogenase, lactate, creatinine, red blood cell transfusion, need for hemodialysis, use of vasoactive drugs, endotracheal intubation time, length of stay in the intensive care unit (ICU), and length of hospital stay—were compared.ResultsGroup A (CIT < 8 hours) presented less need for red blood cell transfusions (odds ratio 0.29; confidence interval 0.06-0.98; P = .04), had a shorter hospital stay (P = .024), and had lower levels of total bilirubin (P = .05) and GGT (P = .05) in the first 7 postoperative days. The other variables showed no statistically significant difference.ConclusionIn livers preserved with Custodiol, CIT > 8 hours generated higher levels of total bilirubin and GGT in the postoperative period, in addition to higher hospital costs; greater need for red blood cell transfusions; and longer hospitalization, including longer stays in the ICU.     

Factors leading to long-term hospitalization after laparoscopic appendectomy.

BACKGROUND: Randomized studies demonstrate that laparoscopic appendectomy yields better results compared with open techniques. We sought to identify factors that determine an extended hospital stay among patients undergoing laparoscopic appendectomy. METHODS: This was a prospective study including 669 patients undergoing laparoscopic appendectomy. We analyzed variables that can predict the length of hospital stay. RESULTS: Of 669 patients undergoing laparoscopic appendectomy, 141 stayed in the hospital for > or = 5 days (Group 1), and 97 stayed in the hospital for < or = 1 day after surgery (Group 2). The univariate analysis demonstrated that fever (P<0.0001), nausea and vomiting (P=0.060), leukocytosis (P<0.0001), gangrened or perforated intraoperative appearance of the appendix (P<0.0001), and appendix position behind the ileocecal junction (P<0.001) were related to a longer hospital stay. The multivariate analysis through logistical regression showed that the factors independently and significantly associated with an extended hospital stay were presurgical fever, appendix position behind the ileocecal junction, and intraoperative gangrened or perforated appearance of the appendix. CONCLUSION: Fever, appearance, and position of the appendix are factors related to an extended hospital stay.