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Patency and caliber of the internal jugular vein after neck dissection
Auris Nasus Larynx 30 (2003) 269 /272 www.elsevier.com/locate/anl
Patency and caliber of the internal jugular vein after neck dissection Hiroyuki Harada a,*, Ken Omura a, Yosuke Takeuchi b a
Oral Surgery, Department of Oral Restitution, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan b Division of Head and Neck Surgery, Chiba Cancer Center Hospital, Chiba, Japan Received 19 September 2002; received in revised form 10 January 2003; accepted 14 March 2003
Abstract Objective: To determine the incidence of thrombosis and change in caliber of the internal jugular vein after neck dissection. Patients and methods: Between September 1999 and December 2000, we studied 68 patients who underwent 76 neck dissection that spared the internal jugular vein. Thrombosis of the internal jugular vein was determined using duplex Doppler scans. The examination was performed about 10 days after the operation. Preoperative and postoperative imaging was available for 28 patients who underwent 32 neck dissections after April 2000. These 28 patients were divided into three groups. Group 1 consisted of 5 internal jugular veins which were treated with supraomohyoid neck dissection. Group 2 included 17 internal jugular veins which were treated with functional neck dissection. For group 3, ten patients underwent simultaneous bilateral neck dissections that spared the ipsilateral internal jugular vein with concurrent contralateral radical neck dissection. For each group, the mean ratio of the postto pre-operative caliber of the internal jugular vein was calculated. Measurements were planned for 7 days, 1 month, and 3 months postoperatively. Results: The overall patency of the 76 internal jugular veins after neck dissection was 100%. In all groups, the mean ratio of the post- to pre-operative caliber of the internal jugular vein was lowest during the early postoperative period, and gradually increased within 3 months after surgery. Conclusion: The caliber of the internal jugular veins decreased the most during the early postoperative period; however, internal jugular vein thrombosis is uncommon. # 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: Internal jugular vein; Thrombosis; Caliber
1. Introduction The incidence of internal jugular vein thrombosis (IJVT) after neck dissection ranges from 0 to 29.6% [1 / 8]. The most feared complication of IJVT, although uncommon, is pulmonary embolism. Ahmed and Payne reported a 5% incidence of pulmonary embolism in IJVT [9]. In addition, IJVT may increase the risk of postoperative venous congestion and edema, particularly when bilateral neck dissections are performed, while providing venous access for free flap transfer. The incidence of narrowed but patent vein after neck dissection has been reported as 3.8 /64.7% [1 /3,10]. In these reports, however, the definition of ‘narrow vein’ was vague; for instance, a narrowed lumen was defined
* Corresponding author. 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138549, Japan. Tel.: /81-3-5803-5508; fax: /81-3-5803-0199. E-mail address: [email protected] (H. Harada).
as occurring when IJV markedly reduced the caliber or when the diameter of the dissected IJV was one-half or less of the diameter of the undissected IJV. Because the finding of venous narrowing is regarded as one of the factors that could encourage thrombus formation after neck dissection [10], changes in the caliber of IJV should be assessed definitively before and after neck dissection. There have been few reports on the sequential evaluation of patency and caliber of the IJV after neck dissection. In this study, we present the incidence of thrombosis and change in caliber of the IJV after neck dissection.
2. Materials and methods Here we studied 68 patients who underwent 76 neck dissections that spared the internal jugular vein from September 1999 to December 2000 at Chiba Cancer
0385-8146/03/$ - see front matter # 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0385-8146(03)00053-1
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H. Harada et al. / Auris Nasus Larynx 30 (2003) 269 /272
Table 1 Location of primary tumor
Center Hospital. There were 45 male and 23 female patients, with a mean age of 61.9 years. Primary tumor sites are shown in Table 1. Neck disease was classified according to the criteria of International Union Against Cancer (UICC). Table 2 illustrates the neck stage of the study patients. Forty-eight patients underwent 54 modified radical neck dissection which dissected at least level II, III, IV sparing IJV and 20 patients underwent 22 supraomohyoid neck dissection. Nineteen patients underwent flap reconstruction utilizing venous outflow to the left side of the neck, and 20 underwent an anastomosis on the right side. Free flap donor sites consisted of the forearm flap in 14 patients, rectus abdominal flap in 11 patients, jejunum flap in 7 patients, anterior lateral thigh flap and scapular flap in 3 patients each, and fibular flap in 1 patient. Forty-six patients had received radiotherapy prior to surgery and six patients required postoperative radiotherapy. All the patients had been evaluated before surgery with a CT scan and had patent jugular veins. Postoperatively, the patency of the 76 IJVs was determined by duplex Doppler ultrasound examinations. The postoperative test was performed about 10 days (mean, 10.1 days; range 5/23) after the operation. The patients were scanned in the supine position, and the patency of the IJV were assessed at the level of omohyoid muscle in patients with supraomohyoid neck dissection, and the supraclavicle in patients with modified radical neck dissection. Table 2 N-stage
Preoperative and postoperative imaging was available for 28 patients who underwent a total of 32 neck dissections after April 2000. These 28 patients were divided into three groups. The group 1 consisted of 5 IJVs which were treated with supraomohyoid neck dissection. Group 2 included 17 IJVs which dissected at least level II, III, IV sparing the IJV. Ten patients in group 3 underwent simultaneous bilateral neck dissections, sparing the ipsilateral IJV as a minimum levels II through IV with concurrent contralateral radical neck dissection. For each group, the ratio of the post-over the preoperative caliber of the IJV was calculated. Measurements were planned for 7 days, 1 month, and 3 months postoperatively. A number of scheduling difficulties arose that resulted in patients being studied on other days. Initially, we attempted to evaluate changes in flow, in addition to patency and caliber of IJV. However, as shown in the Fig. 1, spike of flow speed was often irregular in the case of decreasing flow of IJV after surgery. Hence, we abandoned to evaluate changes in flow using this method because the data was not reliable. The patients were scanned in the supine position, and the patency and caliber of the IJV were assessed at the level of omohyoid muscle in group 1, and the supraclavicle in groups 2 and 3. Significant variation in diameter is known to occur between the patients because of changes in cardiovascular status, position, respiratory cycle, and owing to technical inconsistency [11]. The position of patients was controlled in these studies. The scans were all performed by one person (HH) using a Doppler ultrasound machine (LOGIQ 500 MD, YOKOGAWA, Japan) with a 7.5-MHz transducer. The ultrasonic duplex scanner used provides simultaneous real-time B mode images and a signal gate pulsed Doppler flow to detect velocity changes. Informed consent was obtained from all patients. The difference of the caliber of IJV in each group was analyzed using the Mann-Whitney U test. A P -value B/ 0.05 was considered statistically significant.
3. Results In our study, the overall patency of the 76 IJVs after neck dissection was 100%. No thrombosis was noted in any vein, although some veins were difficult to identify because they were so narrow, postoperatively. Fig. 2 shows the mean ratio of the post-over the preoperative caliber of the IJV after days 7, 1 month, and 3 months after surgery. The data was as follows: 0.770, 0.942, 1.019 in group 1; 0.655, 0.673, 0.716 in group 2; and 0.716, 0.875, 0.980 in group 3. The caliber of the IJVs decreased during the early postoperative period and gradually increased within 3 months after surgery. No significant difference in the caliber of IJV
H. Harada et al. / Auris Nasus Larynx 30 (2003) 269 /272
271
Fig. 1. (A) Duplex ultrasound image revealed the internal jugular vein 7 days after surgery. (B) Ultrasound scan demonstrating the patent jugular vein but the irregular pulsed Doppler trace. IJV, internal jugular vein; CCA, common carotid artery.
Fig. 2. The mean ratio of the post-over the preoperative caliber of the IJV, 7 days, 1 month, and 3 months after surgery. The caliber of the IJVs decreased during the early postoperative period, and gradually increased within 3 months after surgery.
between each group was revealed at 7 days and 1 month after surgery. At 3 month after surgery, there was significant difference in the caliber of IJV between group 2 and 3 (P /039), whereas no significant difference between group 1 and 2 was found.
4. Discussion There are several risk factors for internal jugular thrombosis after neck dissection. Nonoperative factors and intraoperative technical events may impact the patency rate of the IJV following a neck dissection.
Nonoperative factors that have been reported are postoperative radiotherapy [10], placement of a central catheter [9,12], external compression from a flap or drain [2], and infection [4,13]. Surgical factors that can help avoid thrombosis include the following: (1) atraumatic manipulation of the vein; (2) avoiding thermal injury with the electrocautery; (3) avoiding desiccation of the jugular, once it is denuded of adventitia; (4) maintenance of optimal flow characteristics by ligation of jugular side branches far enough from the vein to avoid constriction in diameter but close enough to prevent blind jugular side pouches, which may contribute to turbulent flow and retrograde thrombosis [7]. In our study, the overall patency of the IJV after neck dissection was 100%. It is considered that we administered a gentler dissection technique with being careful these cautions. Our analysis of the mean ratio of the post- to preoperative caliber of the IJV 7 days, 1 month, and 3 months after surgery, showed that the caliber of the IJVs decreased during the early postoperative period. During surgery, systemic circulating blood volume often falls, and hypovolemia is also common in the immediate postoperative period. As the activities of daily living are resumed after this period, it is believed that the jugular flow is gradually recovered. In addition, stretching the fibrosis and scar tissue of the neck may have caused the caliber of IJVs to gradually increase within the 3 months after surgery. Although it is reported that venous narrowing is one of the factors that could encourage thrombus formation after neck dissection [10], this study could not clarify that the relationship between the caliber of the IJV and IJVT because none of the all IJVs showed thrombosis.
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H. Harada et al. / Auris Nasus Larynx 30 (2003) 269 /272
In group 2, the mean ratio between the post- and preoperative caliber of the IJV, 7 days, 1 month, and 3 months after surgery was 0.655, 0.673, and 0.716, respectively. In these cases, the branches draining into the IJV were ligated, which may have led to a decrease in the flow of the IJV. It is hypothesized that the ligation of venous branches draining into IJV could result in a decrement in the caliber of the IJV. On the other hand, although the number of cases was small, the caliber of the IJV recovered to the preoperative level in 3 months in group 1, even though the venous branches draining into the IJV were ligated in this group as well. However, the cause of the difference between group 1 and 2 is unknown. Further study is necessary to understand this inconsistency. The mean ratio of the post-to preoperative caliber of the IJV in group 3 was higher than in group 2. At 3 month after surgery, there was statistically significant difference between two groups. Lake et al. reported that sacrifice of the ipsilateral IJV apparently resulted in a compensatory flow increase in the remaining contralateral IJV [11]. This could explain the reason of the difference between groups 2 and 3. In conclusion, the caliber of the IJVs decreased the most during the early postoperative period; however, this study indicates that IJVT is uncommon.
References [1] Fisher CB, Mattox DE, Zinreich JS. Patency of the internal jugular vein after functional neck dissection. Laryngoscope 1988;98:923 /7.
[2] Cotter CS, Stringer SP, Landau S, Mancuso AA, Cassisi NJ. Patency of the internal jugular vein following modified radical neck dissection. Laryngoscope 1994;104:841 /5. [3] Zohar Y, Strauss M, Sabo R, Sadov R, Sabo G, Lehman J. Internal jugular vein patency after functional neck dissection: venous duplex imaging. Ann Otol Rhinol Laryngol 1995;104:532 /6. [4] Leontsinis TG, Currie AR, Mannell A. Internal jugular vein thrombosis following functional neck dissection. Laryngoscope 1995;105:169 /74. [5] Quraishi HA, Wax MK, Granke K, Rodman SM. Internal jugular vein thrombosis after functional and selective neck dissection. Arch Otolaryngol Head Neck Surg 1997;123:969 /73. [6] Wax MK, Quraishi H, Rodman S, Granke K. Internal jugular vein patency in patients undergoing microvascular reconstruction. Laryngoscope 1997;107:1245 /8. [7] Brown DH, Mulholland S, Yoo JHJ, Gullane PJ, Irish JC, Neligan P, et al. Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction. Head Neck 1998;20:169 /74. [8] Prim MP, Diego JI, Fernandez-Zubillaga A, Garcia-Raya P, Madero R, Gavilan J. Patency and flow of the internal jugular vein after functional neck dissection. Laryngoscope 2000;110:47 / 50. [9] Ahmed N, Payne R. Thrombosis after central venous cannulation. Med J Aust 1976;1:217 /20. [10] Docherty JG, Carter R, Sheldon CD, Falconer JS, Bainbridge C, Robertson AG, et al. Relative effect of surgery and radiotherapy on the internal jugular vein following functional neck dissection. Head Neck 1993;15:553 /6. [11] Lake GM, Dianrdo LJ, Demeo JH. Performance of the internal jugular vein after functional neck dissection. Otolaryngol Head Neck Surg 1994;111:201 /4. [12] Chowdhury K, Bloom J, Black MJ, Al-Noury K. Spontaneous and nonspontaneous internal jugular vein thrombosis. Head Neck 1990;12:168 /73. [13] Lin CH, Chou JC, Lin TL, Lou PJ. Spontaneous resolution of internal jugular thrombosis in a Salmonella neck abscess patient. J Laryngol Otol 1999;113:1122 /4.
Patency and caliber of the internal jugular vein after neck dissection Hiroyuki Harada a,*, Ken Omura a, Yosuke Takeuchi b a
Oral Surgery, Department of Oral Restitution, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan b Division of Head and Neck Surgery, Chiba Cancer Center Hospital, Chiba, Japan Received 19 September 2002; received in revised form 10 January 2003; accepted 14 March 2003
Abstract Objective: To determine the incidence of thrombosis and change in caliber of the internal jugular vein after neck dissection. Patients and methods: Between September 1999 and December 2000, we studied 68 patients who underwent 76 neck dissection that spared the internal jugular vein. Thrombosis of the internal jugular vein was determined using duplex Doppler scans. The examination was performed about 10 days after the operation. Preoperative and postoperative imaging was available for 28 patients who underwent 32 neck dissections after April 2000. These 28 patients were divided into three groups. Group 1 consisted of 5 internal jugular veins which were treated with supraomohyoid neck dissection. Group 2 included 17 internal jugular veins which were treated with functional neck dissection. For group 3, ten patients underwent simultaneous bilateral neck dissections that spared the ipsilateral internal jugular vein with concurrent contralateral radical neck dissection. For each group, the mean ratio of the postto pre-operative caliber of the internal jugular vein was calculated. Measurements were planned for 7 days, 1 month, and 3 months postoperatively. Results: The overall patency of the 76 internal jugular veins after neck dissection was 100%. In all groups, the mean ratio of the post- to pre-operative caliber of the internal jugular vein was lowest during the early postoperative period, and gradually increased within 3 months after surgery. Conclusion: The caliber of the internal jugular veins decreased the most during the early postoperative period; however, internal jugular vein thrombosis is uncommon. # 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: Internal jugular vein; Thrombosis; Caliber
1. Introduction The incidence of internal jugular vein thrombosis (IJVT) after neck dissection ranges from 0 to 29.6% [1 / 8]. The most feared complication of IJVT, although uncommon, is pulmonary embolism. Ahmed and Payne reported a 5% incidence of pulmonary embolism in IJVT [9]. In addition, IJVT may increase the risk of postoperative venous congestion and edema, particularly when bilateral neck dissections are performed, while providing venous access for free flap transfer. The incidence of narrowed but patent vein after neck dissection has been reported as 3.8 /64.7% [1 /3,10]. In these reports, however, the definition of ‘narrow vein’ was vague; for instance, a narrowed lumen was defined
* Corresponding author. 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138549, Japan. Tel.: /81-3-5803-5508; fax: /81-3-5803-0199. E-mail address: [email protected] (H. Harada).
as occurring when IJV markedly reduced the caliber or when the diameter of the dissected IJV was one-half or less of the diameter of the undissected IJV. Because the finding of venous narrowing is regarded as one of the factors that could encourage thrombus formation after neck dissection [10], changes in the caliber of IJV should be assessed definitively before and after neck dissection. There have been few reports on the sequential evaluation of patency and caliber of the IJV after neck dissection. In this study, we present the incidence of thrombosis and change in caliber of the IJV after neck dissection.
2. Materials and methods Here we studied 68 patients who underwent 76 neck dissections that spared the internal jugular vein from September 1999 to December 2000 at Chiba Cancer
0385-8146/03/$ - see front matter # 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0385-8146(03)00053-1
270
H. Harada et al. / Auris Nasus Larynx 30 (2003) 269 /272
Table 1 Location of primary tumor
Center Hospital. There were 45 male and 23 female patients, with a mean age of 61.9 years. Primary tumor sites are shown in Table 1. Neck disease was classified according to the criteria of International Union Against Cancer (UICC). Table 2 illustrates the neck stage of the study patients. Forty-eight patients underwent 54 modified radical neck dissection which dissected at least level II, III, IV sparing IJV and 20 patients underwent 22 supraomohyoid neck dissection. Nineteen patients underwent flap reconstruction utilizing venous outflow to the left side of the neck, and 20 underwent an anastomosis on the right side. Free flap donor sites consisted of the forearm flap in 14 patients, rectus abdominal flap in 11 patients, jejunum flap in 7 patients, anterior lateral thigh flap and scapular flap in 3 patients each, and fibular flap in 1 patient. Forty-six patients had received radiotherapy prior to surgery and six patients required postoperative radiotherapy. All the patients had been evaluated before surgery with a CT scan and had patent jugular veins. Postoperatively, the patency of the 76 IJVs was determined by duplex Doppler ultrasound examinations. The postoperative test was performed about 10 days (mean, 10.1 days; range 5/23) after the operation. The patients were scanned in the supine position, and the patency of the IJV were assessed at the level of omohyoid muscle in patients with supraomohyoid neck dissection, and the supraclavicle in patients with modified radical neck dissection. Table 2 N-stage
Preoperative and postoperative imaging was available for 28 patients who underwent a total of 32 neck dissections after April 2000. These 28 patients were divided into three groups. The group 1 consisted of 5 IJVs which were treated with supraomohyoid neck dissection. Group 2 included 17 IJVs which dissected at least level II, III, IV sparing the IJV. Ten patients in group 3 underwent simultaneous bilateral neck dissections, sparing the ipsilateral IJV as a minimum levels II through IV with concurrent contralateral radical neck dissection. For each group, the ratio of the post-over the preoperative caliber of the IJV was calculated. Measurements were planned for 7 days, 1 month, and 3 months postoperatively. A number of scheduling difficulties arose that resulted in patients being studied on other days. Initially, we attempted to evaluate changes in flow, in addition to patency and caliber of IJV. However, as shown in the Fig. 1, spike of flow speed was often irregular in the case of decreasing flow of IJV after surgery. Hence, we abandoned to evaluate changes in flow using this method because the data was not reliable. The patients were scanned in the supine position, and the patency and caliber of the IJV were assessed at the level of omohyoid muscle in group 1, and the supraclavicle in groups 2 and 3. Significant variation in diameter is known to occur between the patients because of changes in cardiovascular status, position, respiratory cycle, and owing to technical inconsistency [11]. The position of patients was controlled in these studies. The scans were all performed by one person (HH) using a Doppler ultrasound machine (LOGIQ 500 MD, YOKOGAWA, Japan) with a 7.5-MHz transducer. The ultrasonic duplex scanner used provides simultaneous real-time B mode images and a signal gate pulsed Doppler flow to detect velocity changes. Informed consent was obtained from all patients. The difference of the caliber of IJV in each group was analyzed using the Mann-Whitney U test. A P -value B/ 0.05 was considered statistically significant.
3. Results In our study, the overall patency of the 76 IJVs after neck dissection was 100%. No thrombosis was noted in any vein, although some veins were difficult to identify because they were so narrow, postoperatively. Fig. 2 shows the mean ratio of the post-over the preoperative caliber of the IJV after days 7, 1 month, and 3 months after surgery. The data was as follows: 0.770, 0.942, 1.019 in group 1; 0.655, 0.673, 0.716 in group 2; and 0.716, 0.875, 0.980 in group 3. The caliber of the IJVs decreased during the early postoperative period and gradually increased within 3 months after surgery. No significant difference in the caliber of IJV
H. Harada et al. / Auris Nasus Larynx 30 (2003) 269 /272
271
Fig. 1. (A) Duplex ultrasound image revealed the internal jugular vein 7 days after surgery. (B) Ultrasound scan demonstrating the patent jugular vein but the irregular pulsed Doppler trace. IJV, internal jugular vein; CCA, common carotid artery.
Fig. 2. The mean ratio of the post-over the preoperative caliber of the IJV, 7 days, 1 month, and 3 months after surgery. The caliber of the IJVs decreased during the early postoperative period, and gradually increased within 3 months after surgery.
between each group was revealed at 7 days and 1 month after surgery. At 3 month after surgery, there was significant difference in the caliber of IJV between group 2 and 3 (P /039), whereas no significant difference between group 1 and 2 was found.
4. Discussion There are several risk factors for internal jugular thrombosis after neck dissection. Nonoperative factors and intraoperative technical events may impact the patency rate of the IJV following a neck dissection.
Nonoperative factors that have been reported are postoperative radiotherapy [10], placement of a central catheter [9,12], external compression from a flap or drain [2], and infection [4,13]. Surgical factors that can help avoid thrombosis include the following: (1) atraumatic manipulation of the vein; (2) avoiding thermal injury with the electrocautery; (3) avoiding desiccation of the jugular, once it is denuded of adventitia; (4) maintenance of optimal flow characteristics by ligation of jugular side branches far enough from the vein to avoid constriction in diameter but close enough to prevent blind jugular side pouches, which may contribute to turbulent flow and retrograde thrombosis [7]. In our study, the overall patency of the IJV after neck dissection was 100%. It is considered that we administered a gentler dissection technique with being careful these cautions. Our analysis of the mean ratio of the post- to preoperative caliber of the IJV 7 days, 1 month, and 3 months after surgery, showed that the caliber of the IJVs decreased during the early postoperative period. During surgery, systemic circulating blood volume often falls, and hypovolemia is also common in the immediate postoperative period. As the activities of daily living are resumed after this period, it is believed that the jugular flow is gradually recovered. In addition, stretching the fibrosis and scar tissue of the neck may have caused the caliber of IJVs to gradually increase within the 3 months after surgery. Although it is reported that venous narrowing is one of the factors that could encourage thrombus formation after neck dissection [10], this study could not clarify that the relationship between the caliber of the IJV and IJVT because none of the all IJVs showed thrombosis.
272
H. Harada et al. / Auris Nasus Larynx 30 (2003) 269 /272
In group 2, the mean ratio between the post- and preoperative caliber of the IJV, 7 days, 1 month, and 3 months after surgery was 0.655, 0.673, and 0.716, respectively. In these cases, the branches draining into the IJV were ligated, which may have led to a decrease in the flow of the IJV. It is hypothesized that the ligation of venous branches draining into IJV could result in a decrement in the caliber of the IJV. On the other hand, although the number of cases was small, the caliber of the IJV recovered to the preoperative level in 3 months in group 1, even though the venous branches draining into the IJV were ligated in this group as well. However, the cause of the difference between group 1 and 2 is unknown. Further study is necessary to understand this inconsistency. The mean ratio of the post-to preoperative caliber of the IJV in group 3 was higher than in group 2. At 3 month after surgery, there was statistically significant difference between two groups. Lake et al. reported that sacrifice of the ipsilateral IJV apparently resulted in a compensatory flow increase in the remaining contralateral IJV [11]. This could explain the reason of the difference between groups 2 and 3. In conclusion, the caliber of the IJVs decreased the most during the early postoperative period; however, this study indicates that IJVT is uncommon.
References [1] Fisher CB, Mattox DE, Zinreich JS. Patency of the internal jugular vein after functional neck dissection. Laryngoscope 1988;98:923 /7.
[2] Cotter CS, Stringer SP, Landau S, Mancuso AA, Cassisi NJ. Patency of the internal jugular vein following modified radical neck dissection. Laryngoscope 1994;104:841 /5. [3] Zohar Y, Strauss M, Sabo R, Sadov R, Sabo G, Lehman J. Internal jugular vein patency after functional neck dissection: venous duplex imaging. Ann Otol Rhinol Laryngol 1995;104:532 /6. [4] Leontsinis TG, Currie AR, Mannell A. Internal jugular vein thrombosis following functional neck dissection. Laryngoscope 1995;105:169 /74. [5] Quraishi HA, Wax MK, Granke K, Rodman SM. Internal jugular vein thrombosis after functional and selective neck dissection. Arch Otolaryngol Head Neck Surg 1997;123:969 /73. [6] Wax MK, Quraishi H, Rodman S, Granke K. Internal jugular vein patency in patients undergoing microvascular reconstruction. Laryngoscope 1997;107:1245 /8. [7] Brown DH, Mulholland S, Yoo JHJ, Gullane PJ, Irish JC, Neligan P, et al. Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction. Head Neck 1998;20:169 /74. [8] Prim MP, Diego JI, Fernandez-Zubillaga A, Garcia-Raya P, Madero R, Gavilan J. Patency and flow of the internal jugular vein after functional neck dissection. Laryngoscope 2000;110:47 / 50. [9] Ahmed N, Payne R. Thrombosis after central venous cannulation. Med J Aust 1976;1:217 /20. [10] Docherty JG, Carter R, Sheldon CD, Falconer JS, Bainbridge C, Robertson AG, et al. Relative effect of surgery and radiotherapy on the internal jugular vein following functional neck dissection. Head Neck 1993;15:553 /6. [11] Lake GM, Dianrdo LJ, Demeo JH. Performance of the internal jugular vein after functional neck dissection. Otolaryngol Head Neck Surg 1994;111:201 /4. [12] Chowdhury K, Bloom J, Black MJ, Al-Noury K. Spontaneous and nonspontaneous internal jugular vein thrombosis. Head Neck 1990;12:168 /73. [13] Lin CH, Chou JC, Lin TL, Lou PJ. Spontaneous resolution of internal jugular thrombosis in a Salmonella neck abscess patient. J Laryngol Otol 1999;113:1122 /4.