101
|
Bateman DK, Millhouse PW, Shahi N, Kadam AB, Maltenfort MG, Koerner JD, Vaccaro AR. Anterior lumbar spine surgery: a systematic review and meta-analysis of associated complications. Spine J 2015; 15:1118-32. [PMID: 25728552 DOI: 10.1016/j.spinee.2015.02.040] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 12/22/2014] [Accepted: 02/18/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND CONTEXT The anterior approach to the lumbar spine is increasingly used to accomplish various surgical procedures. However, the incidence and risk factors for complications associated with anterior lumbar spine surgery (ALS) have not been fully elucidated. PURPOSE To identify and document types of complications and complication rates associated with ALS, determine risk factors for these events, and evaluate the effect of measures used to decrease complication rates. STUDY DESIGN Systematic review and meta-analysis. METHODS A systematic review of the English-language literature was conducted for articles published between January 1992 and December 2013. A MEDLINE search was conducted to identify articles reporting complications associated with ALS. For each complication, the data were combined using a generalized linear mixed model with a binomial probability distribution and a random effect based on the study. Predictors used were the type of procedure (open, minimally invasive, or laparoscopic), the approach used (transperitoneal vs. retroperitoneal), use of recombinant bone morphogenetic protein-2, use of preoperative computed tomography angiography (CTA), and the utilization of an access surgeon. Open surgery was used as a reference category. RESULTS Seventy-six articles met final inclusion criteria and reported complication rates in 11,410 patients who underwent arthrodesis and/or arthroplasty via laparoscopic, mini-open, and open techniques. The overall complication rate was 14.1%, with intraoperative and postoperative complication rates of 9.1% and 5.2%, respectively. Only 3% of patients required reoperation or revision procedures. The most common complications reported were venous injury (3.2%), retrograde ejaculation (2.7%), neurologic injury (2%), prosthesis related (2%), postoperative ileus (1.4%), superficial infection (1%), and others (1.3%). Laparoscopic and transperitoneal procedures were associated with higher complication rates, whereas lower complication rates were observed in patients receiving mini-open techniques. Our analysis indicated that the use of recombinant bone morphogenetic protein-2 was associated with increased rates of retrograde ejaculation; however, there may be limitations in interpreting these data. Data regarding the use of preoperative CTA and an access surgeon were limited and demonstrated mixed benefit. CONCLUSIONS Overall complication rates with ALS are relatively low, with the most common complications occurring at a rate of 1% to 3%. Complication rates are related to surgical technique, approach, and implant characteristics. Further randomized controlled trials are needed to validate the use of preventative measures including CTA and the use of an access surgeon.
Collapse
Affiliation(s)
- Dexter K Bateman
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA.
| | - Paul W Millhouse
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA
| | - Niti Shahi
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA
| | - Abhijeet B Kadam
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA
| | - Mitchell G Maltenfort
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA
| | - John D Koerner
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA
| | - Alexander R Vaccaro
- Department of Orthopaedic Surgery, Rothman Institute/Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107, USA
| |
Collapse
|
102
|
Wang G, Hu J, Liu X, Cao Y. Surgical treatments for degenerative lumbar scoliosis: a meta analysis. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2015; 24:1792-9. [PMID: 25900294 DOI: 10.1007/s00586-015-3942-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 04/07/2015] [Accepted: 04/07/2015] [Indexed: 12/24/2022]
Abstract
PURPOSE Degenerative lumbar scoliosis (DLS) is a spinal deformity that typically develops in adults over 50 years old. Although its etiology is unclear, asymmetric degeneration of the spine is the main cause. Individuals with DLS may experience no symptoms of the deformity, mild symptoms, or severe disability. Most patients with DLS receive conservative treatment, while a small number of patients receive surgery for severe DLS with back pain and/or progressive neurological symptoms. A variety of surgical procedures have emerged. However, a systemic comparison of these surgical procedures is currently unavailable. This study reviews the main outcomes and complications of surgical treatments. METHODS A meta analysis of main outcomes and complications of surgical treatments of DLS was conducted through searching PubMed and EMbase databases. RESULTS A total of 45 studies were included in this study, which were classified into four surgical categories. Nine studies utilized isolated decompression, 12 used short interbody fusion, 17 used long interbody fusion, and 11 studies included patients using short or long interbody fusion or surgery other than fusion, respectively. Decompression surgery is used to release the symptoms of neurogenic claudication. Spine fusion is widely utilized to prevent worsening of the curve. Instrumentation has been used together with fusion to straighten the spine, correct sagittal imbalance, and repair rotational defects. Decompression is commonly combined with fusion surgery when treating an individual with DLS. CONCLUSION Despite a high rate of complications, this review demonstrates that surgery is an effective and reasonable treatment intervention for severe DLS and ultimately improves spine function and deformity. This review also suggests that large scale, high quality studies with long term follow-up are needed to provide more reliable evidence for future evaluation.
Collapse
Affiliation(s)
- Guohua Wang
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China
| | | | | | | |
Collapse
|
103
|
Rhee JW, Petteys RJ, Anaizi AN, Sandhu FA, Voyadzis JM. Prospective evaluation of 1-year outcomes in single-level percutaneous lumbar transfacet screw fixation in the lateral decubitus position following lateral transpsoas interbody fusion. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2015; 24:2546-54. [PMID: 25893335 DOI: 10.1007/s00586-015-3934-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 04/04/2015] [Accepted: 04/05/2015] [Indexed: 01/06/2023]
Abstract
PURPOSE Lateral transpsoas lumbar interbody fusion (LTIF) is an accepted treatment for degenerative lumbar disc disease. Bilateral percutaneous transfacet (TF) fixation is a promising option for stabilization following LTIF. Here, we describe our experience with this technique and assess the clinical outcomes and efficacy. METHODS Thirty-eight consecutive patients were identified who underwent LTIF followed by bilateral percutaneous transfacet fixation in the lateral position. Preoperative and 1-year postoperative VAS scores, and operative data were prospectively recorded. One-year outcomes were also assessed according to the MacNab criteria. Fusion was assessed at 1 year via computed tomography and dynamic radiography. Two-tailed Student's t test was used to compare VAS scores. RESULTS Twenty-six patients underwent fusion at L4-5, 11 at L3-4, and one at L2-3; two patients were lost to follow-up. Mean operative time was 148.0 ± 47.9 min; mean blood loss was 33.0 ± 26.1 ml; mean hospital stay was 53.5 ± 51.2 h. Mean preoperative VAS scores for back and leg pain were 7.4 ± 3.0 and 7.0 ± 2.9, respectively; mean postoperative VAS scores for back and leg pain were 1.9 ± 2.4 (p < 0.0001) and 2.0 ± 3.0 (p < 0.0001), respectively. Most (89 %) patients had some relief, 72 % good to excellent and 17 % fair outcomes; eleven percent had little to no relief. There was one postoperative complication (pulmonary embolus). All patients had evidence of solid bony fusion. CONCLUSIONS Percutaneous transfacet fixation in the lateral position is a safe and effective alternative for fixation after LTIF and may be associated with shorter operative time and less blood loss than other posterior fixation techniques.
Collapse
Affiliation(s)
- Jay W Rhee
- Department of Neurosurgery, Medstar Georgetown University Hospital, 3800 Reservoir Road, NW, PHC-7, Washington, DC, 20007, USA
| | - Rory J Petteys
- Department of Neurosurgery, Medstar Georgetown University Hospital, 3800 Reservoir Road, NW, PHC-7, Washington, DC, 20007, USA.
| | - Amjad N Anaizi
- Department of Neurosurgery, Medstar Georgetown University Hospital, 3800 Reservoir Road, NW, PHC-7, Washington, DC, 20007, USA
| | - Faheem A Sandhu
- Department of Neurosurgery, Medstar Georgetown University Hospital, 3800 Reservoir Road, NW, PHC-7, Washington, DC, 20007, USA
| | - Jean-Marc Voyadzis
- Department of Neurosurgery, Medstar Georgetown University Hospital, 3800 Reservoir Road, NW, PHC-7, Washington, DC, 20007, USA.
| |
Collapse
|
104
|
Uribe JS, Deukmedjian AR. Visceral, vascular, and wound complications following over 13,000 lateral interbody fusions: a survey study and literature review. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2015; 24 Suppl 3:386-96. [DOI: 10.1007/s00586-015-3806-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/08/2015] [Accepted: 02/08/2015] [Indexed: 11/29/2022]
|
105
|
Woo JH, Park HS. Successful treatment of severe sympathetically maintained pain following anterior spine surgery. J Korean Neurosurg Soc 2014; 56:66-70. [PMID: 25289130 PMCID: PMC4185325 DOI: 10.3340/jkns.2014.56.1.66] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/27/2014] [Accepted: 07/15/2014] [Indexed: 11/27/2022] Open
Abstract
Sympathetic dysfunction is one of the possible complications of anterior spine surgery; however, it has been underestimated as a cause of complications. We report two successful experiences of treating severe dysesthetic pain occurring after anterior spine surgery, by performing a sympathetic block. The first patient experienced a burning and stabbing pain in the contralateral upper extremity of approach side used in anterior cervical discectomy and fusion, and underwent a stellate ganglion block with a significant relief of his pain. The second patient complained of a cold sensation and severe unexpected pain in the lower extremity of the contralateral side after anterior lumbar interbody fusion and was treated with lumbar sympathetic block. We aimed to describe sympathetically maintained pain as one of the important causes of early postoperative pain and the treatment option chosen for these cases in detail.
Collapse
Affiliation(s)
- Jae Hee Woo
- Department of Anesthesiology and Pain Medicine, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Hahck Soo Park
- Department of Anesthesiology and Pain Medicine, School of Medicine, Ewha Womans University, Seoul, Korea
| |
Collapse
|
106
|
Malham GM, Parker RM, Ellis NJ, Blecher CM, Chow FY, Claydon MH. Anterior lumbar interbody fusion using recombinant human bone morphogenetic protein-2: a prospective study of complications. J Neurosurg Spine 2014; 21:851-60. [PMID: 25279655 DOI: 10.3171/2014.8.spine13524] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECT The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior lumbar interbody fusion (ALIF) is controversial regarding the reported complication rates and cost. The authors aimed to assess the complication rates of performing ALIF using rhBMP-2. METHODS This is a prospective study of consecutive patients who underwent ALIF performed by a single spine surgeon and a single vascular surgeon between 2009 and 2012. All patients underwent placement of a polyetheretherketone (PEEK) cage filled with rhBMP-2 and a separate anterior titanium plate. Preoperative clinical data, operative details, postoperative complications, and clinical and radiographic outcomes were recorded for all patients. Clinical outcome measures included back and leg pain visual analog scale scores, Oswestry Disability Index (ODI), and SF-36 Physical and Mental Component Summary (PCS and MCS) scores. Radiographic assessment of fusion was performed using high-definition CT scanning. Male patients were screened pre- and postoperatively regarding sexual dysfunction, specifically retrograde ejaculation (RE). RESULTS The study comprised 131 patients with a mean age of 45.3 years. There were 67 men (51.1%) and 64 women (48.9%). Of the 131 patients, 117 (89.3%) underwent ALIF at L5-S1, 9 (6.9%) at L4-5, and 5 (3.8%) at both L4-5 and L5-S1. The overall complication rate was 19.1% (25 of 131), with 17 patients (13.0%) experiencing minor complications and 8 (6.1%) experiencing major complications. The mean estimated blood loss per ALIF level was 115 ml. There was 1 incidence (1.5%) of RE. No significant vascular injuries occurred. No prosthesis failure occurred with the PEEK cage and separate anterior screw-plate. Back and leg pain improved 57.2% and 61.8%, respectively. The ODI improved 54.3%, with PCS and MCS scores improving 41.7% and 21.3%, respectively. Solid interbody fusion was observed in 96.9% of patients at 12 months. CONCLUSIONS Anterior lumbar interbody fusion with a vascular access surgeon and spine surgeon, using a separate cage and anterior screw-plate, provides a very robust and reliable construct with low complication rates, high fusion rates, and positive clinical outcomes, and it is cost-effective. The authors did not experience the high rates of RE reported by other authors using rhBMP-2.
Collapse
|
107
|
Prior abdominal surgery is associated with an increased risk of postoperative complications after anterior lumbar interbody fusion. Spine (Phila Pa 1976) 2014; 39:E650-6. [PMID: 24583724 DOI: 10.1097/brs.0000000000000293] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective medical record review. OBJECTIVE The purpose of this study was to determine whether a history of abdominal/pelvic surgery confers an increased risk of retroperitoneal anterior approach-related complications when undergoing anterior lumbar interbody fusion. SUMMARY OF BACKGROUND DATA As anterior lumbar interbody fusion gains popularity, both anterior retroperitoneal approach have become increasingly used. METHODS The records of 263 patients, who underwent infraumbilical retroperitoneal approach to the anterior aspect of the lower lumbar spine for a degenerative spine condition between 2007 and 2011 were retrospectively reviewed. Patient's demographics, risk factors, preoperative diagnosis, surgical history, level of the anterior fusion, and perioperative complications were collected. Anterior retroperitoneal approach to the spine was carried out by a single general surgeon. RESULTS Ninety-seven patients (37%) developed at least 1 complication. Forty-nine percent of patients with a history of abdominal surgery developed a postoperative complication compared with 28% of patients without such history (RR = 1.747, P≤ 0.001). After controlling for other factors such as age, sex, body mass index, diagnostic groups, and preoperative comorbidities (hypertension, diabetes, and smoking status), these differences remained statistically significant. When each type of complication was considered separately, there was a statistically significant difference in the incidence of general complications (RR = 2.384, P = 0.007), instrumentation-related complications (RR = 2.954, P = 0.010), and complications related to the anterior approach (RR = 1.797, P = 0.021). CONCLUSION Anterior lumbar interbody fusion via a midline incision and a retroperitoneal approach was associated with 37% overall rate of complication. Patients with a history of abdominal or pelvic surgery are at a higher risk of developing general, instrumentation, and anterior approach-related complications.
Collapse
|
108
|
Rothenfluh DA, Koenig M, Stokes OM, Behrbalk E, Boszczyk BM. Access-related complications in anterior lumbar surgery in patients over 60 years of age. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2014; 23 Suppl 1:S86-92. [PMID: 24531989 DOI: 10.1007/s00586-014-3211-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 11/28/2022]
Abstract
PURPOSE The anterior approach is widely used for access to the lumbar spine in the setting of adult deformity either as a stand-alone procedure or in combined anterior-posterior procedures. Access-related complication rates have so far not been reported in an elderly patient population, in which it has been suggested that anterior lumbar surgery is indicated with caution. Here, the complication rates in patients over 60 years of age are reported. METHODS A retrospective chart review in a consecutive series of 31 patients over 60 years of age and in which a retroperitoneal access to the lumbar spine was performed. All charts including anaesthetic charts were reviewed and the patients' demographics, exact surgical procedure, comorbidities, and potential risk factors, as well as intraoperative and vascular complications noted. Patients who had revision anterior surgery, anterior surgery for tumour resection, trauma or infection were excluded. RESULTS The average age of patients was 64.9 years, ranging 60-81. Eighteen patients were female and 13 male. The average body mass index was 26.7 ranging 18.5-44.0. The indications for surgery were degenerative scoliosis (12 patients), degenerative spondylosis (7 patients), degenerative spondylolisthesis (5 patients), iatrogenic spondylolisthesis following prior posterior decompression (5 patients), and pseudarthrosis following posterolateral instrumented fusion (2 patients). In 10 patients, a single-level anterior lumbar interbody fusion (ALIF) was carried out (1 L3/4, 5 L4/5, 4 L5/S1) and in 11 patients ALIF was performed on two levels (1 L2-4, 1 L3-5, 9 L4-S1). In three patients, 3 levels from L3 to S1 were approached and in seven patients 4 levels from L2 to S1. Patients with three- and four-level anterior lumbar surgery had higher blood loss than two- and one-level surgery (616 ± 340 vs 439 ± 238, p = 0.036). The overall complication rate was 29% (9/31), which included four vascular injuries and one pulmonary embolism. The vascular complication rate was 13% (4/31) with two arterial and two venous injuries requiring repair. No major blood loss over 2,000 ml occurred. CONCLUSIONS Anterior lumbar surgery in an elderly population does not necessarily have higher overall complication rates than in a younger population. The risk of vascular injury requiring repair was higher, but has not resulted in major blood loss and the procedure therefore can be carried out safely. The overall complication rate and blood loss compare favourably to complication rates in posterior adult deformity procedures.
Collapse
Affiliation(s)
- Dominique A Rothenfluh
- The Centre for Spinal Studies and Surgery, Queens Medical Centre, Nottingham University Hospitals NHS Trust, Derby Road, Nottingham, NG7 2UH, UK,
| | | | | | | | | |
Collapse
|
109
|
Mulholland RC, Clamp JC, Boszczyk BM. A short history of spinal training and outlook on spine speciality development in the UK 1948-2013. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2013; 22 Suppl 1:S1-4. [PMID: 23328876 DOI: 10.1007/s00586-013-2667-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
110
|
Behrbalk E, Uri O, Parks RM, Musson R, Soh RCC, Boszczyk BM. Fusion and subsidence rate of stand alone anterior lumbar interbody fusion using PEEK cage with recombinant human bone morphogenetic protein-2. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2013; 22:2869-75. [PMID: 23955421 DOI: 10.1007/s00586-013-2948-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 07/22/2013] [Accepted: 08/03/2013] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Anterior lumbar interbody fusion (ALIF) is an established treatment for structural instability associated with symptomatic disk degeneration (SDD). Stand-alone ALIF offers many advantages, however, it may increase the risk of non-union. Recombinant human bone morphogenetic protein-2 (BMP-2) may enhance fusion rate but is associated with postoperative complication. The optimal dose of BMP-2 remains unclear. This study assessed the fusion and subsidence rates of stand-alone ALIF using the SynFix-LR interbody cage with 6 ml/level of BMP-2. METHODS Thirty-two ALIF procedures were performed by a single surgeon in 25 patients. Twenty-five procedures were performed for SDD without spondylolisthesis (SDD group) and seven procedures were performed for SDD with grade-I olisthesis (SDD-olisthesis group). Patients were followed-up for a mean of 17 ± 6 months. RESULTS Solid fusion was achieved in 29 cases (90.6 %) within 6 months postoperatively. Five cases of implant subsidence were observed (16 %). Four of these occurred in the SDD-olisthesis group and one occurred in the SDD group (57 % vs. 4 % respectively; p = 0.004). Three cases of subsidence failed to fuse and required revision. The body mass index of patients with olisthesis who developed subsidence was higher than those who did not develop subsidence (29 ± 2.6 vs. 22 ± 6.5 respectively; p = 0.04). No BMP-2 related complications occurred. CONCLUSION The overall fusion rate of stand-alone ALIF using the SynFix-LR system with BMP-2 was 90.6 %, comparable with other published series. No BMP-2 related complication occurred at a dose of 6 mg/level. Degenerative spondylolisthesis and obesity seemed to increase the rate of implant subsidence, and thus we believe that adding posterior fusion for these cases should be considered.
Collapse
Affiliation(s)
- Eyal Behrbalk
- The Spine Unit, Queen's Medical Centre, Nottingham, UK,
| | | | | | | | | | | |
Collapse
|