ABSTRACT
Background
The risk of internal jugular vein thrombosis is a concern when using the internal jugular vein as a recipient vein in microvascular head and neck reconstruction. This study aimed to investigate the incidence of internal jugular vein thrombosis within 2 weeks of microvascular head and neck reconstruction using computed tomographic angiography.
Methods
This retrospective study included 103 patients who underwent postoperative contrast‐enhanced computed tomography within 2 weeks of microvascular head and neck reconstruction. The incidence, characteristics, treatment course, outcomes, and risk factors of internal jugular vein thrombosis were investigated.
Results
Internal jugular vein thrombosis was found in five cases (4.7%). In three of these cases (2.8%), internal jugular vein thrombosis occurred on the side of the microvascular anastomosis, and all of them were completely obstructed; however, the flaps survived without vascular compromise. No variables were considered risk factors for internal jugular vein thrombosis.
Conclusions
The incidence of internal jugular vein thrombosis after microvascular head and neck reconstruction was lower than previously reported. Most cases of internal jugular vein thrombosis are assumed to be subclinical and do not lead to anastomotic failure. It remains unclear whether asymptomatic internal jugular vein thrombosis on the anastomotic side should be treated.
Level of Evidence
3.
1. Introduction
Internal jugular vein (IJV) is the most frequently used recipient vein in microvascular head and neck reconstruction (Kohyama et al. 2025; Philips et al. 2024; Takeishi et al. 2024). The advantages of the IJV include its large diameter, high blood flow, and respiratory venous pump effect (Ueda et al. 1996). End‐to‐side anastomosis of the IJV overcomes discrepancies in vessel size and allows the anastomotic site to be placed at any level of the neck (Halvorson and Cordeiro 2007). Furthermore, several authors have reported that the IJV system is more reliable as a recipient than the external jugular vein; (Fukuiwa et al. 2008; Reiter and Baumeister 2017); however, the greatest concern when using the IJV as a recipient vein is the risk of IJV thrombosis (IJVT). The incidence of IJVT after modified neck dissection has been reported to be as high as 15%–30% (Brown et al. 1998; Quraishi et al. 1997). IJVT on the anastomotic side can cause vascular compromise of the transferred flap; however, the reported incidence of flap failure due to IJVT is very low, (Miyasaka et al. 2005), which has been explained by the overdiagnosis of IJVT due to modality issues or partial occlusion of the IJV, but no consensus has been reached (de Bree et al. 2002; Wax et al. 1997). To elucidate this, it is necessary to diagnose IJVT early in the postoperative period using a uniform and objective diagnostic method and to evaluate the effect of IJVT on flap survival when it occurs.
This study aimed to investigate the rate of IJVT within 2 weeks of microvascular head and neck reconstruction. We conducted a retrospective case series using computed tomography scans, and the clinical course of the patients who developed IJVT and its effects on flap survival was also investigated.
2. Patients and Methods
This study was conducted according to the STROBE guideline for case control studies. Immediate microvascular reconstruction was performed in 158 patients with head and neck cancer at our hospital between April 2018 and March 2022. This retrospective case series included 103 patients who underwent postoperative contrast‐enhanced computed tomography (CT) within 2 weeks. The patients comprised 86 men and 17 women with a mean age of 66.9 years (range, 41–87 years). This retrospective study was approved by our institutional review board (approval number: 10527‐(5)).
The medical records of the 103 patients included in the study were analyzed for the following variables: sex, age, preoperative body mass index, primary tumor site, side of neck dissection, flap type, recipient vessels, operative time, operative blood loss, day of postoperative CT, presence or absence of IJVT on CT, treatment of IJVT, flap survival, and fate of IJVT.
The criteria for diagnosing IJVT with contrast‐enhanced CT were defined as follows: “Complete occlusion” was defined as “no contrast agent filling is detected within the IJV lumen in any single axial cross‐section, and no contrast agent continuity was observed in the coronal cross‐section either.” “Partial occlusion” was defined as “a thrombus is observed within the IJV lumen, but contrast agent continuity is maintained”. “Date of IJVT resolution” was “the day on which no thrombus was detected on enhanced CT.”
Flap perfusion was monitored according to standard postoperative management routines. For cutaneous flaps, blood flow was assessed using a pin prick test. For intestinal flaps, a monitoring jejunum was externalized and monitored for 1 week.
3. Statistical Analysis
Statistical analysis of the background and surgical variables comparing patients with and without IJVT was performed using SPSS Statistics version 23 (IBM Corp., Armonk, NY, USA). Quantitative variables were analyzed using Student's t‐test. Categorical variables were analyzed using Fisher's exact test. Differences were considered statistically significant at p < 0.05.
4. Results
The primary tumor sites were the following: hypopharynx (n = 37); intraoral cavity (n = 27); oropharynx (n = 11); paranasal sinus (n = 9); salivary gland (n = 4); larynx (n = 4); and other sites (n = 11). Twenty patients previously received neck radiation.
Modified neck dissection with preservation of the IJV was performed bilaterally in 60 patients and hemilaterally in 32. Neck dissection was not performed in 11 patients. The types of flap used were the following: jejunum (n = 47); anterolateral thigh flap (n = 27); rectus abdominis flap (n = 20); scapular osteocutaneous flap (n = 4); fibular osteocutaneous flap (n = 3); and latissimus dorsi musculocutaneous flap (n = 2). The recipient veins were the following: IJV (n = 95); external jugular vein (n = 6); and the facial vein (n = 2). All anastomoses to the IJV were end‐to‐side.
Postoperative contrast‐enhanced CT was performed from postoperative days 1 to 10, with an average of 5.4 days. The reasons for performing contrast‐enhanced CT were as follows: screening (n = 60); systemic inflammatory signs (n = 17); local infectious signs (n = 16); poor oxygenation (n = 4); increased D‐dimer levels (n = 2); and other reasons (n = 4).
Five (4.7%) cases of IVJT were diagnosed using contrast‐enhanced CT. No statistically significant differences were found between patients with and without IJVT for any of the variables (Table 1). The recipient vein was the IJV in all of the patients with IJVT. All patients were diagnosed within 1 week of surgery. In three of these cases, IJVT occurred on the anastomotic side with complete obstruction; in two cases, the occlusion was on the cranial side of the anastomosis, and in one case, the occlusion was on the cardiac side of the anastomosis. In the remaining two cases of the five cases with IJVT, the IJVT occurred on the contralateral side of the anastomosis with a partial occlusion. Four of the five patients with IJVT were heparinized immediately after diagnosis and subsequently changed to direct oral anticoagulants. The remaining case, wherein the IJVT occurred on the contralateral side of the anastomosis, was followed up without anticoagulation therapy.
TABLE 1.
Comparison of patient backgrounds and surgical variables.
| Number of patients (%) | p | ||
|---|---|---|---|
| IJVT (−) (n = 98) | IJVT (+) (n = 5) | ||
| Age (years, mean) | 66.9 | 66.2 | 0.87 |
| Sex | 1 | ||
| Male | 81 (82.7) | 4 (80.0) | |
| Female | 17 (17.3) | 1 (20.0) | |
| Body mass index (kg/m2, mean) | 22.9 | 21.3 | 0.55 |
| Primary site of the tumor | 0.85 | ||
| Hypopharynx | 34 (34.7) | 3 (60.0) | |
| Intraoral | 26 (26.5) | 1 (20.0) | |
| Oropharynx | 11 (11.2) | 0 | |
| Paranasal sinus | 8 (8.2) | 1 (20.0) | |
| Parotid gland | 4 (4.1) | 0 | |
| Larynx | 4 (4.1) | 0 | |
| Thyroid | 3 (2.9) | 0 | |
| Nasal cavity | 2 (1.9) | 0 | |
| Cervical esophagus | 2 (1.9) | 0 | |
| Ear | 1 (1.0) | 0 | |
| Pterygopalatine fossa | 1 (1.0) | 0 | |
| Double | 2 | ||
| Previous radiotherapy to the neck | 1 | ||
| Yes | 19 (19.4) | 1 (20.0) | |
| No | 79 (80.6) | 4 (80.0) | |
| Neck dissection | 0.63 | ||
| Bilateral | 57 (58.2) | 3 (60.0) | |
| Hemilateral | 31 (31.6) | 1 (20.0) | |
| None | 10 (10.2) | 1 (20.0) | |
| Flap type | 0.30 | ||
| Jejunum | 44 (44.9) | 3 (60.0) | |
| Anterolateral thigh | 27 (27.6) | 0 | |
| Rectus abdominis | 19 (19.4) | 1 (20.0) | |
| Scapula | 3 (3.1) | 1 (20.0) | |
| Fibula | 3 (3.1) | 0 | |
| Latissimus dorsi | 2 (2.0) | 0 | |
| Operative time (min, mean) | 604 | 587 | 0.82 |
| Operative blood loss (mL, mean) | 577 | 681 | 0.60 |
Abbreviation: IJVT, internal jugular vein thrombosis.
Postoperatively, all the flaps survived without vascular compromise. Even in the three cases with IJVT on the anastomotic side, the flaps survived without signs of flap congestion.
In the four patients with IJVT treated with heparin, there were no cases of bleeding or other adverse events associated with anticoagulation therapy. Eventually, the IJVT resolved in all patients. The resolution varied from 8 days to 6 months postoperatively. One case showed persistent stenosis of the IJV but no clinical symptoms. In other cases, neither stenosis nor clinical symptoms were observed (Table 2).
TABLE 2.
Patients with IJVT.
| Age | Sex | Primary site of tumor | Flap type | Postoperative CT (days) | Side of IJVT | Side of venous anastomosis | Occlusion of IJV | Position of IJVT in relation to anastomotic site | Treatment of IJVT | Date of IJVT dissolution (POD) | IJV stenosis after dissolution |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 65 | F |
Upper gingiva (recurrent) |
Scapula | 6 | Right | Right | Complete | Cranial |
Heparin 5000 U (6‐15POD) Edoxaban 30 mg (16‐94POD) |
55 | + |
| 74 | M |
Nasal cavity (recurrent) |
Rectus abdominis | 4 | Left | Left | Complete | Cranial |
Heparin 5000 U (4‐8POD) Edoxaban 30 mg (16‐196POD) |
188 | − |
| 72 | M | Hypopharynx | Jejunum | 2 | Left | Left | Complete | Cardiac |
Heparin 20,000 U (2‐17POD) Rivaroxaban 15 mg (18‐POD) |
25 | − |
| 57 | M | Hypopharynx | Jejunum | 1 | Left | Right | Partial | − |
Heparin 10,000 U (4‐8POD) Rivaroxaban 10 mg (2‐281POD) |
8 | − |
| 63 | M | Hypopharynx | Jejunum | 3 | Right | Left | Partial | − | − | 289 | − |
Abbreviations: CT, computed tomography; IJV, internal jugular vein; IJVT, internal jugular vein thrombosis; POD, postoperative day; POM, postoperative month.
5. Case Report
A 72‐year‐old man presented with a squamous cell carcinoma of the hypopharynx (T4aN2bM0) and underwent a total pharyngolaryngectomy, left hemithyroidectomy, bilateral modified neck dissection, and free jejunal transfer. The vascular pedicle of the jejunum was anastomosed to the vessels of the left side of the neck. The artery was anastomosed to the superior thyroid artery in end‐to‐end fashion, while the vein was anastomosed to the internal jugular vein in end‐to‐side fashion (Figure 1). The operative time was 10 h and 16 min. The blood loss was 510 mL. A segment of the jejunum was externalized for postoperative monitoring.
FIGURE 1.
Intraoperative appearance of the microvascular anastomotic site during free jejunum transfer. The jejunal vein was anastomosed to the left internal jugular vein in end‐to‐side fashion (arrow).
On the second postoperative day, the patient was in good general condition, and the wound was clear; however, the contrast‐enhanced CT that was performed for screening showed a left IJVT and pulmonary embolism. An IJVT was found on the cardiac side of the anastomosis, and the IJV was not completely occluded. The anastomotic site was patent. Circulation of the monitored jejunum and blood oxygen level of the body were normal. Systemic heparinization was initiated immediately. Follow‐up CT on postoperative day 7 revealed an enlarged thrombus and complete occlusion of the IJV; however, the thrombus did not extend to the anastomotic site. Circulation of the monitored jejunum was still normal (Figure 2). At this point, venous return of the jejunum was thought to have been obtained by retrograde blood flow of the left IJV in the cranial direction. CT on postoperative day 15 showed that the thrombus of the IJVT had diminished in size and the pulmonary embolism had disappeared (Figure 3). Oral feeding was initiated on the same day. On postoperative day 18, the heparin was changed to a direct oral anticoagulant. CT on postoperative day 25 revealed that the thrombus had disappeared. The patient was discharged on postoperative day 30. The patient was disease‐free 42 months after surgery and was able to consume regular food orally.
FIGURE 2.
Appearance of the monitoring segment of the transferred jejunum on postoperative days 2 (left), 7 (center), and 15 (right) in a patient with left internal jugular vein thrombosis.
FIGURE 3.
Contrast‐enhanced computed tomography images on postoperative days 2 (left), 7 (center), and 15 (right) in a patient with left internal jugular vein thrombosis. Axial planes (above) at the venous anastomotic site (arrows). Axial planes (below) at the internal jugular vein thrombosis (arrowheads). On day 2, a thrombus was observed; however, the internal jugular vein was not completely occluded. On day 7, the thrombus enlarged, and the internal jugular vein was completely occluded. On day 15, the thrombus diminished in size.
6. Discussion
The results of the current study demonstrated that the incidence of IJVT in the acute phase after microvascular head and neck reconstruction, as revealed by contrast‐enhanced CT, was 4.7%. Even in cases wherein IJVT occurred on the anastomotic side, flap circulation was not affected.
The incidence of IJVT in the current study was lower than previous reports, which have reported incidence rates exceeding 20%. Wax et al. (1997) reported that IJVT occurred in 29.6% of patients who underwent microvascular head and neck reconstruction. All IJVT occurred within 1 week after surgery. Duplex Doppler ultrasound examinations were used for the diagnosis. It is possible that there were false positives due to diagnostic accuracy issues, which they themselves described as a possibility. Kitano et al. (2021) reported that the incidence of IJVT was 21.6% in a similar patient population. They included IJVT observed within the first 3 months after surgery, and more than half of the IJVT cases were diagnosed after 8 days postoperatively. In contrast, the current study was limited to CT scans performed within 2 weeks, and all IJVT cases were diagnosed within 1 week postoperatively. The strength of this study lies in its use of a uniform imaging diagnostic method and its focus on the occurrence of IJVT during the acute postoperative period. The first postoperative week is critical for flap survival, and the results of the current study may have better reflected the true risk of IJVT for flap survival. Although it is difficult to compare the incidence of IJVT between reports owing to differences in diagnostic methods and timing of diagnosis, the incidence of IJVT within the first postoperative week does not appear to be as high as the 20%–30% reported in previous studies.
The occurrence of IJVT on the anastomotic side could lead to flap compromise because the flap vein was anastomosed to the IJV in most patients; however, in the current study, no flap compromise occurred in cases where the IJVT occurred on the anastomotic side. Miyasaka et al. (2005) reported 4 cases (0.6%) of postoperative flap congestion due to IJVT out of 640 cases with end‐to‐side anastomosis to the IJV. Fukuiwa et al. (2008) reported that IJVT caused flap compromise in 2 (2.8%) out of 70 cases. These authors agreed that the difference in the incidence of IJVT and flap compromise can be explained by the presence of subclinical IJVT. In fact, IJVT on the anastomotic side does not necessarily lead to flap compromise (Kubo et al. 2002). If contrast‐enhanced CT had not been performed, the five cases of IJVT in the current study could have been noted as subclinical IJVT.
The results of the current study enabled detailed analysis of the location and occlusion status of IJVT and its effects on flap circulation. These results imply that the relationship between the site of IJVT onset and the anastomotic site is critical. Partial obstruction is unlikely to be a problem unless it reaches the anastomotic site. Similarly, complete obstruction is unlikely to be a problem if it occurs cephalad to the anastomotic site. This is consistent with the report by Akazawa et al. (2019) that reported the safety of end‐to‐side anastomosis to a ligated stump. Even if complete occlusion occurs on the cardiac side of the anastomotic site, this may not be a problem if the retrograde pathway is maintained (Kubo et al. 2002). A venous network to the contralateral side through the face or intracranial vessels may be the collateral pathway.
In the case reported here, wherein IJVT occurred on the cardiac side of the anastomosis with complete occlusion, IJVT was discovered on the second postoperative day, at which time it was a partial occlusion but became a complete occlusion on the seventh postoperative day. Gradual progression of occlusion may have secured the collateral pathways; however, further studies are needed to determine the locations of the collateral pathways.
The treatment for asymptomatic IJVT after head and neck surgery has not yet been established. In the present study, patients with anastomotic IJVT were treated with systemic heparin and direct oral anticoagulants to prevent thrombus extension. Occlusion of the anastomotic site due to IJVT extension was the most serious consequence and should be avoided. The risk of pulmonary embolism from IJVT should also be considered; however, in cases with early postoperative onset, there is a risk of wound hemorrhage associated with drug therapy. In the long term, most IJVTs are expected to undergo recanalization without treatment; therefore, the benefit of drug therapy is dubious (Quraishi et al. 1997; Wax et al. 1997). The timing of IJVT diagnosis may be an important factor in determining the indication for drug therapy. Further studies are required to determine whether asymptomatic IJVT should be treated with drugs after microvascular head and neck reconstruction.
The main limitation of this study is its retrospective design. Postoperative CT was not performed in all patients who underwent microvascular head and neck reconstruction; thus, there may have been a selection bias (Supporting Informations S1 and S2). Another limitation was that the number of days wherein CT was performed varied. These biases may have affected the incidence of IJVT in this study. The last limitation was that the small number of the events (n = 5). Due to this, the risk factor analysis may have type II errors, and the results should be interpreted with caution. Further studies addressing these limitations are necessary.
7. Conclusions
In the current study, the incidence of IJVT using contrast‐enhanced CT within 2 weeks after head and neck microvascular reconstruction was 4.7%, which is lower than previous reports. In three patients (2.8%), IJVT occurred on the anastomotic side; however, the flaps survived without vascular compromise. Based on our results, we assume that most IJVTs are subclinical and do not lead to anastomotic failures.
Author Contributions
D.K., S.M. and O.M. designed and conceived this study. Y.S., K.K. and K.F. collected data. D.K. and S.M. analyzed and interpreted the results and drafted the manuscript. All authors read and approved the final manuscript.
Funding
The authors have nothing to report.
Ethics Statement
The authors have nothing to report.
Conflicts of Interest
The authors declare no conflicts of interest.
Supporting information
Supporting Information: S1. Comparison of patient backgrounds and surgical variables.
Supporting Information: S2. Distribution charts of the propensity score using logistic regression analysis with age, sex, body mass index, prior radiation therapy history, and neck dissection as covariates for the CT‐ and CT+ groups.
Kurita, D. , Miyamoto S., Saito Y., Kobayashi K., Fujisawa K., and Okazaki M.. 2026. “Prevalence of Subclinical Internal Jugular Vein Thrombosis After Microvascular Head and Neck Reconstruction.” Microsurgery 46, no. 1: e70183. 10.1002/micr.70183.
Data Availability Statement
Data sharing not applicable to this article as no datasets were generated or analysed during the current study.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Supporting Information: S1. Comparison of patient backgrounds and surgical variables.
Supporting Information: S2. Distribution charts of the propensity score using logistic regression analysis with age, sex, body mass index, prior radiation therapy history, and neck dissection as covariates for the CT‐ and CT+ groups.
Data Availability Statement
Data sharing not applicable to this article as no datasets were generated or analysed during the current study.