to allow identification of specific cells and to correlate the bone marrow cellularity with cytopenias in the peripheral blood Choice of aspiration or biopsy site-The iliac crest is the only site at which both aspiration and biop sy may be safely performed in the adult. .The poste superior ilia cres nd spine(fiqure 1)is the favore ed site of examination in the adult,as well as in the child and in most infants This site also provides the least discomfort to the patient compared with other sites. .The anterior iliac crest(fiqure 2)may be used for bone marrow as n nd biopsy in ad when access the posterior ilia crest is limited (eg,the patient is unable to be moved for proper access to the chosen aspiration site.morbid obesity.skin diseases.or previous radiation)[2.14].An initial attempt to sample the posteror iliac bone may be worthwhile even in neonates b may be rnbs.s8eater obtained fro m the trochanter of th ur,individu vertebral bodies IC procedures,including open bone biopsies,are best obtained through surgical consultation,and may require CT guidance(see 'Surgical iopsy'below). .Obtaining bone marrow fro m a site which has been previously irradiated o yield subopt espe overa cellularity.Another site should be chosen if at all possible. Bone marrow may be aspirated from the stemumin patients over 12 years of age(fiqure 3),although biopsy at this site is contr because of it minimal thickness.Special care needs to be taken if this site is chosen for marrow aspiration,since penetration of the inner table of the stemnum or penetration through a rib interspace may lead to fatal hemorrhage (see 'Complications'below). In premature infants and some full-terminfants,the iliac bone has not completely ossified,and an altemative bone(eg,the anterior portion of the tibia)should be used [18).If the anterior tibia must be entered,it should only b sed for aspiration and limited to infants younger than 18months of age On occasion,it may not be possible to identify an aspiration/biopsy site e cause of t ence of excessive adipose tissue;su rface landmarks s may be difficult to identify and/or the available needle may not reach the bone surface (see 'Technique'below and'Needle selection'below).If these maneuvers have failed,one solution is to perform the procedure using computed tomography (CD quidance [191. In cases in which the landmarks can be identified but the needle is too short, a trephine biopsy needle may be used for both the aspiration and biopsy. (See 'Needle selection'below.)
to allow identification of specific cells and to correlate the bone marrow cellularity with cytopenias in the peripheral blood. Choice of aspiration or biopsy site — The iliac crest is the only site at which both aspiration and biopsy may be safely performed in the adult. ●The posterior superior iliac crest and spine (figure 1) is the favored site of examination in the adult, as well as in the child and in most infants. This site also provides the least discomfort to the patient compared with other sites. ●The anterior iliac crest (figure 2) may be used for bone marrow aspiration and biopsy in adults when access to the posterior iliac crest is limited (eg, the patient is unable to be moved for proper access to the chosen aspiration site, morbid obesity, skin diseases, or previous radiation) [2,14]. An initial attempt to sample the posterior iliac bone may be worthwhile, even in neonates. ●In selected cases, bone marrow may be obtained from the greater trochanter of the femur, individual vertebral bodies, or ribs. Such procedures, including open bone biopsies, are best obtained through surgical consultation, and may require CT guidance (see 'Surgical biopsy' below). ●Obtaining bone marrow from a site which has been previously irradiated is likely to yield suboptimal results, especially in terms of overall cellularity. Another site should be chosen if at all possible. Bone marrow may be aspirated from the sternum in patients over 12 years of age (figure 3), although biopsy at this site is contraindicated because of its minimal thickness. Special care needs to be taken if this site is chosen for marrow aspiration, since penetration of the inner table of the sternum or penetration through a rib interspace may lead to fatal hemorrhage (see 'Complications'below). In premature infants and some full-term infants, the iliac bone has not completely ossified, and an alternative bone (eg, the anterior portion of the tibia) should be used [18]. If the anterior tibia must be entered, it should only be used for aspiration and limited to infants younger than 18 months of age. On occasion, it may not be possible to identify an aspiration/biopsy site because of the presence of excessive adipose tissue; surface landmarks may be difficult to identify and/or the available needle may not reach the bone surface (see 'Technique' below and 'Needle selection' below). If these maneuvers have failed, one solution is to perform the procedure using computed tomography (CT) guidance [19]. In cases in which the landmarks can be identified but the needle is too short, a trephine biopsy needle may be used for both the aspiration and biopsy. (See 'Needle selection' below.)
Premedications-the pain perceived by the patientdurina bone marrow biopsy pero ed underlocal anesthesia is lo vto moderate being approx on a 0 to 10 scale in one stu dy [20]and 1.7 on a0 to5 scale in another [21].While premedications,including anxiolytics or opiates. are notusually necessary [221.certain individuals with underlving dense bone structure.pain issues.or those with heightened anxiety may benefit from the use of such agents.It cannot be overstated that the quality of the specimen obtained may be stly superior in cooperativ e and com patient. In children with procedure phobias,the use of lorazepam under carefully dnican be very beneficial.producing bothreax antegrade zepan n or trama may na nilar adults with anxiety [23-26].This can be particularly helpful if the child or anxious adultis likely to require multiple bone marrow evaluations over a period of time,as in the treatment of acute leukemia.A safe conscious sedation policy should be in place prior to using drugs such as benzodiazepines or opioids in patients of any age The use of inhaled nitrous oxide and oxvaen.an established combination used for pain management and sedation in certain gynecologicprocedures well-tole erated and effective for u se during bone marrow aspiration and biopsy:use of this agent may diminish the risk of prolonged sedation associated with benzodiazepine or opioid dosing [27-29]. However,given the limited nature of these studies,further research may be required before the use of nitrous oxide/oxygen is accepted into standard practice Any premedications should be administered in a timely fashion,prior to Use of an assistant-Bone marrow aspirates and biopsies often clot within minutes of being ained.During this time, h n perf the procedure may still be busy performing an aspiration or biopsy at the same or another site,reassuring the patient,or initiating local hemostasis.Ideally, bone marrow aspiration and biopsy be carried out with the help of a trained pare the slides and specimens or who assist tant who can either nepp completion of the procedure. in achieving adequate hemos Needle selection-Disposable aspiration and biopsy needles are preferred in order to guarantee sterility and sharpness,as well as to reduce procedure- and"failure"rat [301 Allc vailable needles are lfor piraion and biopy ofcrestForste the needle should have a guard which screws securely to a selected portion of the needle in order to limit its penetration(see'Stemal aspiration'below)
Premedications — The pain perceived by the patient during bone marrow aspiration and biopsy performed under local anesthesia is low to moderate, being approximately 3 on a 0 to 10 scale in one study [20] and 1.7 on a 0 to 5 scale in another [21]. While premedications, including anxiolytics or opiates, are not usually necessary [22], certain individuals with underlying dense bone structure, pain issues, or those with heightened anxiety may benefit from the use of such agents. It cannot be overstated that the quality of the specimen obtained may be vastly superior in a cooperative and comfortable patient. In children with procedure phobias, the use of lorazepam under carefully controlled conditions can be very beneficial, producing both relaxation and antegrade amnesia; lorazepam or tramadol may have a similar effect in adults with anxiety [23-26]. This can be particularly helpful if the child or anxious adult is likely to require multiple bone marrow evaluations over a period of time, as in the treatment of acute leukemia. A safe conscious sedation policy should be in place prior to using drugs such as benzodiazepines or opioids in patients of any age. The use of inhaled nitrous oxide and oxygen, an established combination used for pain management and sedation in certain gynecologic procedures and in sigmoidoscopy, is both well-tolerated and effective for use during bone marrow aspiration and biopsy; use of this agent may diminish the risk of prolonged sedation associated with benzodiazepine or opioid dosing [27-29]. However, given the limited nature of these studies, further research may be required before the use of nitrous oxide/oxygen is accepted into standard practice. Any premedications should be administered in a timely fashion, prior to performing the procedure, in order to allow for the desired effects [25,26]. (See "Procedural sedation in children outside of the operating room".) Use of an assistant — Bone marrow aspirates and biopsies often clot within minutes of being obtained. During this time, the person performing the procedure may still be busy performing an aspiration or biopsy at the same or another site, reassuring the patient, or initiating local hemostasis. Ideally, bone marrow aspiration and biopsy be carried out with the help of a trained assistant who can either help prepare the slides and specimens or who assist in achieving adequate hemostasis following completion of the procedure. Needle selection — Disposable aspiration and biopsy needles are preferred in order to guarantee sterility and sharpness, as well as to reduce procedurerelated pain and "failure" rates [30]. All commercially available needles are acceptable for aspiration and biopsy of the iliac crest. For sternal aspiration, the needle should have a guard which screws securely to a selected portion of the needle in order to limit its penetration (see 'Sternal aspiration' below)
Occasionally,in obese or large patients,it may be necessary to use a Sequence of aspiration and biops -Althouah the techniques used fo obtaining bon e marrow aspiration and biopsy samples have be nfairly we standardized.there has been some debate as to the sequence of aspiration and biopsy: .Prior studies have demonstrated artifactual reduction in overall cellularity of the bone marrow sample due to acute intramedullary hemorrhage in th when aspiration was foll eRways6moeoenetyo wed by bi psy [31].This ning a longer,deeper specimen which bypasses the aspiration site [32]. .Altemnatively,biopsy followed by aspiration could lead to premature clotting of the aspirated specimen. Despite these issues,it is generally felt that high quality specimens can be obtained,regardless of the order,provided that separate needles and 8ap8ce0e8owocentmeesapanaongheiaces0aeusedio Adequacy of the biopsy specimen-Biopsies consisting mostly of cortical bone.cartilage,or muscle,v are least 5 mm in length.In some cases,more extensive sampling may be required. Obtaining an adequate biopsy from a single site in a patientwith non-Hodgkin ymphoma(NHL)has been deemed inadequate by a number of studies. (See"Clinical presentation and diagnosis of non-Hodgkin lymphoma",section on Bone marrow examination'.) .An early study involving 282 patients with lymphoma and other neoplastic diseases revealed accurate diagnosis with unilateral biopsy in only 22 percent of patients with NHL,43 percent of patients with Hodgkin ympho and 36 pe t of th ewith other neoplastic sses [33]. The investigators concluded that bilateral sampling could yield ar additional 11 to 22 percent of positive biopsies. .Another study,including 170 specimens from 145 patients,found that accurate diagnosis improved 26 percent when bilateral specimens were obtained [341 A third study of 260 patients with NHL revealed that 30 percent of positive marrows had unilateral involvement only,supporting the need for bilateral sampling [35]
Occasionally, in obese or large patients, it may be necessary to use a trephine biopsy needle for both the aspiration and biopsy at the iliac crest, as this needle tends to be longer than a standard aspiration needle. Sequence of aspiration and biopsy — Although the techniques used for obtaining bone marrow aspiration and biopsy samples have been fairly well standardized, there has been some debate as to the sequence of aspiration and biopsy: ●Prior studies have demonstrated artifactual reduction in overall cellularity of the bone marrow sample due to acute intramedullary hemorrhage in the biopsy specimen when aspiration was followed by biopsy [31]. This effect was shown to be overcome by obtaining a longer, deeper specimen which bypasses the aspiration site [32]. ●Alternatively, biopsy followed by aspiration could lead to premature clotting of the aspirated specimen. Despite these issues, it is generally felt that high quality specimens can be obtained, regardless of the order, provided that separate needles and separate sites (one to two centimeters apart along the iliac crest) are used for each procedure [32]. Adequacy of the biopsy specimen — Biopsies consisting mostly of cortical bone, cartilage, or muscle, without sufficient sampling of the medullary cavity are inadequate for proper evaluation. Most laboratories require a sample at least 5 mm in length. In some cases, more extensive sampling may be required. Obtaining an adequate biopsy from a single site in a patient with non -Hodgkin lymphoma (NHL) has been deemed inadequate by a number of studies. (See "Clinical presentation and diagnosis of non-Hodgkin lymphoma", section on 'Bone marrow examination'.) ●An early study involving 282 patients with lymphoma and other neoplastic diseases revealed accurate diagnosis with unilateral biopsy in only 22 percent of patients with NHL, 43 percent of patients with Hodgkin lymphoma, and 36 percent of those with other neoplastic processes [33]. The investigators concluded that bilateral sampling could yield an additional 11 to 22 percent of positive biopsies. ●Another study, including 170 specimens from 145 patients, found that accurate diagnosis improved 26 percent when bilateral specimens were obtained [34]. ●A third study of 260 patients with NHL revealed that 30 percent of positive marrows had unilateral involvement only, supporting the need for bilateral sampling [35]