Total Parathyroidectomy Without Autotransplantation for Secondary Hyperparathyroidism

Background  To treat secondary hyperparathyroidism with subtotal parathyroidectomy or total parathyroidectomy with autotransplantation might cause the disease to recur because of growth of the parathyroid remnant or the autografts. The aim of the present study was to determinate an alternative surgical treatment for secondary hyperparathyroidism. Methods  Of 94 uremic patients, 44 (median age: 50.5 years; 33 women/11 men) were assigned to group A, patients who were not expected to receive kidney transplantation for various reasons and had total parathyroidectomy without autotransplantation; 50 (median age 46 years; 33 women/17 men) were assigned to group B, patients who had either total parathyroidectomy with autotransplantation or subtotal total parathyroidectomy with preservation of parathyroid tissue in situ. Parameters measured included demographics, perioperative and follow-up biochemistry tests, operative time, postoperative complications, length of hospital stay, patients’ compliance with the postoperative calcium and 1,25 dihydroxy-viatmin D supplementation regimen, symptom relief, and presence of recurrence. Results  Mean operative times were 103 and 122 min (P = 0.007); postoperative complication rates were 18.2% and 12.0% (P = 0.563); mean hospital stays were 6 and 9 days (P = 0.259); adequate patient compliance with the postoperative calcium and 1,25 dihydroxy-viatmin D regimens were 84.1% and 78.0%, respectively (P = 0.6); symptom relief rates were 88.6% and 80.0% (P = 0.277). Recurrence rates over 60 months in group A and group B were 4.5% and 18.0%, resectively (P = 0.028 by Kaplan-Meier analysis). Conclusions  Because of the lower recurrent rate and shorter operative time, total parathyroidectomy without autotransplantation may be an option for treating patients with symptomatic secondary hyperparathyroidism who are not expected to receive kidney transplantation.     

甲状旁腺切除及无水酒精注射治疗继发性甲状旁腺功能亢进

目的：探讨甲状旁腺切除及腺体内无水酒精注射两种方式治疗继发性甲状旁腺功能亢进（SHPT）的疗效及安全性。方法：17例SHPT患者分为甲状旁腺切除组7例及甲状旁腺无水酒精注射组10例,术后腺体送检病理,观察药物注射前后腺体超声信号变化及术后并发症,记录血清学指标并随访1年。结果：腺体长径大于1.0cm病理改变呈结节样增生,无水酒精注射后腺体血流信号减少。两组术后钙、磷、碱性磷酸酶及甲状旁腺激素水平变化差异存在统计学意义（P〈0.01）,两组术后患者症状均有改善,并发症少,但手术组疗效优于注射组。结论：甲状旁腺切除治疗严重继发性甲状旁腺功能亢进效果确切,临床作为首选,甲状旁腺无水酒精注射治疗可作为单一腺体增生或甲状旁腺切除后的补充治疗。     

QuiCk-IntraOperative Bio-Intact PTH Assay at Parathyroidectomy for Secondary Hyperparathyroidism

Background In uremic patients, metabolism of 1-84 parathyroid hormone (PTH) and fragments are delayed, and in these patients, the usefulness of intraoperative PTH assay may be problematic. We evaluated the usefulness of the QuiCk-IntraOperative Bio-Intact PTH (QPTH) assay for uremic patients with secondary hyperparathyroidism who required total parathyroidectomy (PTx) with forearm autograft. The purpose of our study was to recognize whether QPTH in uremic patients was useful to determine during operation whether complete PTx had been achieved. Methods Forty-four patients who underwent initial PTx were enrolled in this study. Blood samples were drawn just after induction of general anesthesia (basal samples), immediately after removal of the last gland, and at 5, 10, 15, and 30 minutes, and at the first morning after PTx. The assay was performed immediately after sample collection. Reductions of PTH levels were evaluated and expressed in percentage of basal levels. Results The mean PTH levels in 41 patients, excluding 3 in whom the PTH level did not drop significantly (>60 pg/ml), measured by QPTH at anesthesia, 0, 5, 10, 15, and 30 minutes were 734.3, 104.7, 58.8, 37.4, 27.0, 16.3 pg/ml, corresponding to 100%, 17.1%, 9.3%, 5.8%, 4.1%, 2.4% of the preexcision values, respectively. If the cutoff value was defined as 10.8% at 10 minutes, the sensitivity was 100% and specificity 90%. When the QPTH level dropped to under 10.8% at 10 minutes, we could consider that all glands were removed. Conclusions QPTH in uremic patients is very useful to determine whether complete PTx is achieved during operation.     

Aluminum Overload Hampers Symptom Improvement Following Parathyroidectomy for Secondary Hyperparathyroidism

Background

Aluminum overload and accumulation in tissues may lead to skeletal, hematological, and neurological toxicity. The aim of this study was to assess the effects of serum aluminum levels on presentations, postoperative recovery, and symptom improvement in patients undergoing parathyroidectomy for secondary hyperparathyroidism.

Methods

From 2008 to 2013, all patients with end-stage renal disease undergoing initial parathyroidectomy were included in the study. Serum aluminum level was measured preoperatively and/or within 1 week after surgery. Preoperative and postoperative biochemical profile and symptoms were compared between the low and high aluminum groups.

Results

A total of 176 patients were included in the study. Of these, 38 (22 %) patients had serum aluminum levels higher than 20 μg/L. A higher percentage of patients in the high aluminum group were on peritoneal dialysis than in the low aluminum group (24 vs. 4 %, p = 0.001). Both groups had similar bone mineral density and changes in biochemical profiles. The preoperative parathyroidectomy assessment of symptoms (PAS) score was not associated with serum aluminum levels (p = 0.349), whereas the postoperative PAS score showed positive association (p = 0.005). There was a negative association between serum aluminum levels and the improvement of total PAS scores (p = 0.001). The high aluminum group had more residual symptoms in three aspects: bone pain (p = 0.038), difficulty getting out of a chair or car (p = 0.045), and pruritus (p = 0.041).

Conclusions

A high serum aluminum level was associated with reduced symptom improvement in patients undergoing parathyroidectomy for secondary hyperparathyroidism.     

Location Frequency of Missed Parathyroid Glands After Parathyroidectomy in Patients with Persistent or Recurrent Secondary Hyperparathyroidism

Background

Reoperative parathyroidectomy (RPTX) because parathyroid glands have been missed is frequently required in patients with secondary hyperparathyroidism (SHPT). The usual locations of these missed glands in patients with SHPT are yet to be fully elucidated.

Methods

We retrospectively investigated the locations of missed glands in 165 patients who underwent RPTX for persistent or recurrent SHPT at our institution from August 1982 to July 2014. At our institution, total parathyroidectomy with forearm autograft is the routine operative procedure for SHPT. We also routinely resect the thymic tongue.

Results

Of 165 patients, 82 underwent initial parathyroidectomy at our institution (Group A), and the remaining 83 underwent initial parathyroidectomy at other institutions (Group B). A total of 239 parathyroid glands were resected (Group A, 93; Group B, 146). Missed glands were most commonly located in the mediastinum (Group A, 22/93) and the thymic tongue (Group B, 31/146).

Conclusions

In patients with persistent or recurrent SHPT, ectopic parathyroid glands are frequently located in the mediastinum and thymic tongue. Therefore, resecting the thymic tongue during the initial operation may reduce the need for RPTX.

     

Persistent and Recurrent Hyperparathyroidism After Total Parathyroidectomy With Autotransplantation

OBJECTIVE: To conduct a retrospective study of 15 patients with persistent (n = 4) and recurrent (n = 11) hyperparathyroidism. SUMMARY BACKGROUND DATA: Secondary hyperparathyroidism may persist or recur because of hyperfunction of the parathyroid remnant or transplanted parathyroid tissue. It is a great challenge to localize the parathyroid tissue either in the neck or at the arm before surgery. METHODS: From June 1994 to June 2000, 15 patients with recurrent and persistent secondary hyperparathyroidism were selected for surgery for the removal of parathyroid tissue. The indications for surgery included bone pain, hypercalcemia, general weakness, and skin itching. Their ages ranged from 23 to 66 years. The average period of persistent hyperparathyroidism after total parathyroidectomy with autotransplantation was 3.8 months; that of recurrent hyperparathyroidism was 53 months. Serum levels of calcium, phosphorus, parathyroid hormone (iPTH), and alkaline phosphatase were measured before surgery and 1 week after surgery. Before surgery, the parathyroid gradient in the blood draining the graft-bearing arm versus the contralateral arm was measured. A 99mTc-sestamibi (MIBI) scan was performed including the neck and the arm area, and a computed tomography (CT) scan of the neck was performed to confirm the localization. The neck and mediastinal exploration was done directly at the side of localization under general anesthesia to remove the parathyroid tissue that had been located with the MIBI scan or CT scan. An arm exploration was done under local anesthesia to remove all parathyroid tissues detected in the MIBI scan or palpable masses during surgery. If all glands were removed, 0.5 x 0.5 x 0.5 cm of tissue (60-100 mg) was maintained in situ or the same amount of tissue was reimplanted. RESULTS: The average ratio of iPTH in the graft-bearing arm to the contralateral arm in the 5 patients with parathyroid tissue in the neck was 1.17 +/- 0.16, and that in the 10 patients with parathyroid at the arm was 14.15 +/- 16.62. A significant difference was found between the two groups. MIBI scans showed parathyroid tissues in the neck in four of five patients and in seven of eight patients at the arm. Computed tomography showed the parathyroid tissues in the neck and mediastinum in five of five patients (100%). Five glands were removed from these five patients, three in the neck, one in the mediastinum, and one in the carotid sheath. In total, 20 glands and 2 half-glands were removed from 10 patients; among these, 14 glands were shown in the MIBI scan. All patients had improvements of symptoms and signs after surgery. Serum levels of calcium, phosphorus, and iPTH decreased rapidly after surgery, but alkaline phosphatase did not. CONCLUSIONS: With the results obtained from the ratio of iPTH of the graft-bearing arm to the contralateral arm, clinical palpation of the arm, MIBI scan, CT scan, careful surgical exploration, and adequate resection, recurrent and persistent secondary hyperparathyroidism can be successfully treated with surgery in the neck or at the arm.     

甲状旁腺次全切除术和甲状旁腺全切除加甲状旁腺自体移植术治疗尿毒症后继发性甲状旁腺功能亢进的疗效

目的 比较尿毒症后继发性甲状旁腺功能亢进（SHPT）行甲状旁腺次全切除术（sPTX）和甲状旁腺全切除（tPTX）加甲状旁腺自体移植（AT）术的疗效。方法 回顾性分析2005年2月至2012年9月期间中国人民武装警察部队新疆生产建设兵团指挥部后勤部医院及新疆维吾尔自治区人民医院行tPTX＋AT （n=57）和sPTX （n=19） 的76例尿毒症后SHPT患者的临床资料,比较2种术式的疗效。结果 76例患者手术成功68例（89.5%）,切除不足8例（10.5%）。76例患者术后骨痛均缓解,皮肤瘙痒症状改善14例（26.9%,14/52）。tPTX＋AT组术后1 d、7 d及6个月的血钙水平均较低（P＜0.05）,术后6个月的iPTH水平较低（P＜0.05）。2组患者的手术时间、术中出血量、住院时间及住院费用比较差异均有统计学意义,tPTX＋AT组均较长或较高（P＜0.05）。术后76例患者均获访,随访时间为6～18个月,中位数为8.7个月。其中tPTX＋AT组死亡2例,复发2例;sPTX组死亡1例,复发7例。sPTX组的复发率较高（P＜0.05）。结论 尿毒症后SHPT行tPTX＋AT的术后1年内复发率较低,行sPTX者更易发生术后复发;但tPTX＋AT组的手术时间、术中出血量、住院时间及住院费用更高（更长或更多）。 2种术式各有优劣,术式选择时需根据情况综合判定。     

Skin Necrosis After Intravenous Calcium Chloride Administration as a Complication of Parathyroidectomy for Secondary Hyperparathyroidism: Report of Four Cases

Intravenous (i.v.) calcium chloride is usually given to treat symptomatic hypocalcemia; however, the extravasation of calcium solution may cause soft tissue and skin necrosis. After parathyroidectomy and autotransplantation for secondary hyperparathyroidism associated with end-stage renal failure, i.v. calcium infusion is often necessary to treat severe postoperative hypocalcemia. We reviewed 371 patients who underwent parathyroidectomy for secondary hyperparathyroidism between January 2000 and June 2005, 96 of whom received i.v. calcium postoperatively for symptomatic hypocalcemia. We report the cases of three (3%) of our own patients and of one patient referred to our hospital, who suffered skin necrosis after i.v. calcium solution administration. These reports show that i.v. calcium should be administered into large veins, or via a central line, and diluted in an appropriate volume of solution. Moreover, the calcium solution infusion should be ceased if the patient complains of tenderness over the injection site. If skin necrosis develops, we suggest early debridement and a simple split thickness skin graft to repair the skin defect. We report our experience to remind surgeons of the danger of calcium chloride injection and to discuss ways of preventing and treating this complication.     

甲状旁腺切除术治疗尿毒症并难治性继发性甲状旁腺机能亢进症

为了观察甲状旁腺切除部分自体移植术治疗尿毒症并难治性甲状旁腺机能亢进症的近远期疗效，定期观测了１２例严重的尿毒症性继发性甲状旁腺机能亢进且采取了甲状旁腺切除部分自体移植术的患者术前及术后第１周、第３，６，１２月其血钙磷代谢，骨Ｘ线及心／胸比值等各项指标。结果显示：①术后各时点血清磷，ＡＫＰ和甲状旁腺素水平明显下降（Ｐ＜０．０５），血清钙虽有所下降，但无统计学意义（Ｐ＞０．０５）；②骨痛及皮肤瘙痒等症状缓解率达９１．６７％；③骨吸收好转率为６６．６７％，术后心／胸比值有所下降，但无统计学意义（Ｐ＞０．０５）；④术前，术后红细胞压积无改变（Ｐ＞０．０５）。结论：甲状旁腺切除部分自体移植术是治疗尿毒症性难治继发性甲状旁腺机能亢进症的有效而可靠的方法     

Muscle Force and Bone Mineral Density after Parathyroidectomy and Subcutaneous Autotransplantation for Secondary Hyperparathyroidism

The object of this study was to determine the muscle force and bone mineral density (BMD) of patients with secondary hyperparathyroidism before and 3 months after operation. Thirty-nine patients with secondary hyperparathyroidism and regular dialysis were operated. Their ages were 47 ± 12 (mean ± SD) years and duration of dialysis was 70.5 ± 35.8 months. The clinical symptoms included bone pain in 23 patients (59%), skin itching in 21 (53.8%), general weakness in 13 (33.3%), conscious disturbance in 2, chest tightness in 1, and failure to thrive in 1. Total parathyroidectomy and autotransplantation of 60 mg of parathyroid gland into subcutaneous tissue was done routinely. BMD was measured in the lumbar spine (L2–L4) and left proximal femur, expressed as grams per square centimeter and as fracture risk. The extension force of the quadriceps muscle was measured at 60 degrees of right knee flexion, expressed as newtons (N) in a peak force and an average force. Three months after operation the BMD of the study group increased (in g/cm²) from 1.063 ± 0.181 to 1.148 ± 0.149 (p < 0.001) in L2–4 (n= 25), from 0.792 ± 0.14 to 0.875 ± 0.161 (p < 0.001), in femoral neck (n= 25), from 0.672 ± 0.171 to 0.754 ± 0.21 (p < 0.001) in Ward's triangle (n= 25), and from 0.69 ± 0.149 to 0.738 ± 0.143 (p < 0.001) in trochanter (n= 25). Fracture risk also was reduced significantly 3 months after operation at L2–4 (p= 0.003), femoral neck (p= 0.001), Ward's triangle (p= 0.003), and trochanter (p= 0.005). Muscle force (in newtons) increased from 264.8 ± 110.5 to 326 ± 110.9 (p= 0.023) in peak force (n= 18) and from 195.3 ± 90.4 to 258 ± 99 (p= 0.012) in average force (n= 18). The patients with general weakness had improved muscle force more prominently than those without general weakness. In addition to skin itching, bone pain, and soft tissue calcification, general weakness that causes disability is an indication for surgery in secondary hyperparathyroidism. After parathyroidectomy and autotransplantation, the muscle force tends to increase, especially in those with general weakness. An increment of BMD and reduction of fracture risk are also found after surgery.     

Total Parathyroidectomy and Autotransplantation by the Subcutaneous Injection Technique in Secondary Hyperparathyroidism

PURPOSE: To prospectively assess the effectiveness of total parathyroidectomy and autotransplantation using a subcutaneous injection technique to treat secondary hyperparathyroidism. METHODS: We used this method to treat 14 patients with secondary hyperparathyroidism. The short-term outcome, up to 16 months after surgery, was monitored by measuring calcium, inorganic phosphorus, intact parathyroid hormone (iPTH), and alkaline phosphatase levels. We considered a graft viable when the ratio of iPHT in antecubital venous blood from the grafted arm to that from the nongrafted arm exceeded 1.5. RESULTS: Autografted parathyroid tissue was functional in 12 (85.7%) patients. An iPTH ratio > or =1.5 in the grafted arm relative to the nongrafted arm was observed from 2 weeks after surgery, peaking at 1 month. The grafted tissue continued to be biochemically functional 16 months after surgery in 12 patients. CONCLUSION: These findings suggest that total parathyroidectomy and forearm autotransplantation using the subcutaneous injection technique is a possible alternative to Wells' method for surgical treatment of secondary hyperparathyroidism.     

Overnight Hospital Stay After Colon Surgery for Adenocarcinoma

A short hospital stay is one of the main advantages of the laparoscopic surgical technique. The process of developing and studying the “fast-track” process has contributed to a better understanding of the elements of perioperative care and has resulted in the reduction in length of stay (LOS) after colectomies. As we follow and refine this well-recognized multimodal approach, further decreases in the LOS can be expected. We present 2 octogenarian patients who, after receiving laparoscopic hemicolectomies for malignant disease, were discharged home <24 hours after their operations. Postoperative follow-ups did not show any adverse reaction to the early discharge. Modifying the multimodal perioperative technique with further refinement to the surgical technique appears to allow patients to be discharged home in the first 24 hours following laparoscopic colectomy.     

The Effect of Parathyroidectomy on Risk of Hip Fracture in Secondary Hyperparathyroidism

Background

Secondary hyperparathyroidism increases the risk for fractures. Despite improvement in medical therapy, surgical parathyroidectomy (PTX) often becomes necessary, but its effect on risk of fractures is not clear. Our aim was to study the effect of parathyroidectomy on the risk of hip fractures in patients on dialysis or with a functioning renal graft at time of parathyroidectomy.

Design

In a cohort of 20,056 patients on dialysis or with functioning renal allograft, we identified 590 patients who underwent parathyroidectomy between 1991 and 2009. Of these, 579 were matched with 1970 non-PTX patients on age, sex, cause of renal disease and functioning renal allograft or not at the time of PTX or at the corresponding time for non-PTX patients (t). We calculated the risk for hip fracture after PTX using crude and adjusted Cox proportional hazards regressions, adjusting for time in renal replacement therapy before t, time with functioning renal allograft before and after t, comorbidity at t and a hip fracture before t.

Results

The adjusted hazard ratio (95% confidence interval) for hip fracture was 0.40 (0.18–0.88) for PTX patients, compared to non-PTX patients. When analyses were performed separately for sex, only women had a lower risk of hip fracture after PTX compared to non-PTX patients. The risk of hip fracture after PTX was similar in patients with or without functioning renal allograft at time for PTX.

Conclusion

Parathyroidectomy is associated with a lower risk of hip fracture in female patients with secondary hyperparathyroidism.

     

Sequential Changes in Plasma Intact and Whole Parathyroid Hormone Levels during Parathyroidectomy for Secondary Hyperparathyroidism

Most commercial assays for intact parathyroid hormone (iPTH) cross-react with non-PTH1-84 fragments (likely to be PTH7-84). We aimed to evaluate a whole PTH assay that measured only PTH1-84 by comparing it with an assay measuring iPTH levels during parathyroidectomy in secondary hyperparathyroidism (HPT). Twenty-eight patients with secondary HPT who underwent total parathyroidectomy with autotransplantation served as subjects. Blood samples for postoperative assay were drawn after anesthesia; immediately prior to excision of the last parathyroid gland; and at 5, 10, and 15 minutes after excision. The PTH7-84 level was calculated by subtracting the whole PTH value from the iPTH value. Plasma whole PTH decreased more rapidly than iPTH after parathyroidectomy (p < 0.0001). PTH levels that decreased by 50% or more from levels prior to excision to 10 minutes after excision were used to predict successful parathyroidectomy; decreases in whole PTH substantiated curative surgery for all patients without introducing false-positive and false-negative results. iPTH levels decreased by at least 50% in only 16 patients at 10 minutes after excision without false-positive results. Out of 11 cases in which iPTH decreased less than 50%, two were true-negatives and nine were false-negatives. Decreases in whole PTH levels more accurately reflect surgical outcome than do decreases in iPTH levels during parathyroidectomy in secondary HPT patients. Even though the quick iPTH assay is used infrequently during surgery for secondary HPT, our results suggest that a quick whole PTH assay may be more useful than the iPTH assay currently used in parathyroidectomy procedures for secondary HPT.     

Parathyroidectomy for Renal Hyperparathyroidism in Children and Adolescents

Background Renal hyperparathyroidism (rHPT) almost inevitably develops in pediatric patients with end-stage chronic kidney disease (CKD) and may require parathyroidectomy (PTX) despite intensified conservative therapy. Long-term duration of uncontrolled rHPT may result in disabling osteodystrophy and vascular calcifications. Only a few reports on children undergoing PTX for rHPT are available and mainly consist of case reports with short follow-up periods. To study this entity, we analyzed the course of 23 pediatic patients who underwent PTX for rHPT. Methods Twenty-three patients with a mean age of 15 years and who underwent PTX for rHPT between 1986 and 2006 were evaluated. Surgical indications and techniques, specific postoperative management, and follow-up courses are described. Results Preoperative mean serum (s-) calcium was 2.7 ± 0.05 mmol/L (normal range = 2.2–2.7 mmol/L); s-phosphate was 1.8 ± 0.1 mmol/L (normal range = 0.8–1.6 mmol/L), and mean intact parathyroid hormone (PTH) level was 1240.1 ± 160.1 pg/ml (normal range = 11–65 pg/ml). Twenty-one patients underwent initial PTX and two patients underwent reoperative PTX. Total PTX with parathyroid autotransplantation (AT) was performed in 18 patients. In three patients less than four parathyroid glands were identified and no AT was performed consecutively. Postoperatively, no complications with respect to bleeding or vocal cord damage were recorded. The postoperative values of s-calcium, s-phosphate, and PTH decreased to or below normal range (s-calcium = 2.0 ± 0.1 mmol/L, s-phosphate = 1.2 ± 0.1 mmol/L, PTH = 50.1 ± 11.2 pg/ml). All 15 children below the age of 15 years required calcium intravenously. Follow-up was obtained in all patients 69.6 ± 11.4 months after PTX. Bone pain resolved in all previously symptomatic patients. S-calcium was 2.2 ± 0.2 mmol/L, s-phosphate was 1.4 ± 0.3 mmol/L, and PTH was 90.2 ± 21.5 pg/ml. No patient required repeated parathyroid autografting, and only one underwent an explantation of his AT six years after initial PTX. Conclusion Total PTX with AT in pediatric patients with rHPT is a safe and effective procedure. It should be considered if rHPT is refractory to conservative treatment, in view of the risk of potentially lethal vascular calcifications developing in the majority of adults with childhood onset of CKD. K. Schlosser and C. P. Schmitt contributed equally to this work.     

Risk Factors for Prolonged Length of Stay After Major Elective Surgery

OBJECTIVE: Length of stay (LOS) is an important outcome as a marker of resource consumption. Determining which factors increase LOS may provide information on reducing costs and improving the delivery of care. The purpose of this study was to determine the independent association of intraoperative process of care and postoperative events with prolonged LOS after adjusting for preoperative severity of illness in patients undergoing major elective surgery. METHODS: Cases representing 11 elective operations from the National VA Surgical Quality Improvement Program were analyzed using multivariate logistic regression analysis. The outcome, prolonged LOS, was defined as an LOS greater than or equal to the 75th percentile (in days) for each operation. Hierarchical modeling was used to assess the independent association of groups of variables (preoperative patient characteristics, intraoperative process of care, and postoperative adverse events) with prolonged LOS. RESULTS: For the 11 operations explored, there were 23,919 cases. Common preoperative variables associated with prolonged LOS were functional status, American Society of Anesthesiology class, and age. The most predictive intraoperative and postoperative variables included intraoperative blood transfusion, operative time, return to the operating room, and the number of complications after surgery. CONCLUSIONS: Prolonged LOS is associated with preoperative, intraoperative, and postoperative factors. Although preoperative factors were independently associated with a prolonged LOS, the factors generating the highest risks for a prolonged LOS were the intraoperative process of care and postoperative adverse events. To reduce costs, efforts should be made to improve the intraoperative process of care and to minimize postoperative complications.