Retroperitoneal abscess with pylephlebitis

Stimulated by Lee et al 2019.[1]

Photo by Anton Nikolov on Unsplash.
My favourite place to get images is Unsplash. It doesn’t have anything on the retroperitoneum or abscesses, so I went with loin, and then kidney, and found this lovely image of a kidney shaped lake.

The title may sound to you like another adverse event report, and you’d be right. But what is pylephlebitis? I didn’t have to look it up as the authors gave an alternative description in the paper, which is in the open access journal BMC Surgery – follow this link and have a look at all the fabulous images. Pylephlebitis is thrombophlebitis of the portal vein or its branches.

The images are great and the story is interesting because it was a bit of a detective mystery for the clinicians involved, but as usual there is insufficient thought concerning the acupuncture and the precise mechanisms involved in this adverse event.

An 80-year-old man presented as an emergency with myalgia and abdominal pain. He appeared to have septic shock and blood tests suggested hepatobiliary disease. The initial CT without contrast showed some abnormalities but no clear source of infection. After several days in a surgical intensive care unit with intravenous fluids and antibiotics he was well enough to undergo contrast enhanced CT. This revealed a 5cm abscess near the sigmoid colon. Since the first CT had suggested the presence of sigmoid diverticula, it was assumed that the abscess was caused by a diverticular perforation. A subsequent sigmoidoscopy failed to find any trace of diverticular disease, so the hunt continued for a cause.

An exploratory laparotomy was performed, and the abscess was found to be unconnected with the sigmoid colon but was retroperitoneal and closely adherent to the aorta and left iliac artery. A complete excision would have involved extensive surgery, so the abscess was drained, and additional antibiotics were added to the regime.

You can imagine a sigh of relief from the authors as they finally put down their magnifying glasses…

Subsequent history taking from the man’s daughter revealed that he had received acupuncture with a long needle in the lumbar area that corresponded exactly with the site of the abscess. You can imagine a sigh of relief from the authors as they finally put down their magnifying glasses (metaphorically speaking – in the manner of Sherlock Holmes perhaps). But unfortunately for us acupuncture types, we needed a touch more investigation that simply was not forthcoming. Everyone had gone home for tea and the patient made an uneventful recovery. All that was left was to write it up and place acupuncture firmly in the frame.

The pus from the abscess grew MRSA (Methicillin-resistant Staphylococcus aureus), but this was not seen on blood cultures, and the original blood cultures on admission grew Escherichia coli. The authors seem to have assumed that MRSA was pushed in on the needle, although this is not stated.

Staphylococcus aureus

Escherichia coli

Klebsiella pneumoniae

Group C Streptococcus

It is a long way from the skin of the back to the retroperitoneal tissues, and I think it is extremely unlikely that an acupuncture needle would manage to carry anything that deep. It seems much more plausible that the long needle reached the large bowel and allowed some Escherichia coli bugs to be dragged back a few millimetres into the retroperitoneum – a much more likely scenario I suggest. If this was the case, then where did the MRSA appear from? Well there is a lot of MRSA around when you are an inpatient, so I imagine it took hold after admission via bacteraemia rather than via an acupuncture needle, the latter being most unlikely in healthy outpatients, which presumably this man was before he had a long needle placed into his bowel (warning, this is my assumption).

The authors claim that this was the first report of a retroperitoneal abscess caused by acupuncture. I am not sure how they missed Cho et al 2003, also from Korea.[2] In the latter case the abscess was 10cm in diameter and appeared as a swelling in the loin. It grew Klebsiella pneumoniae, so I would say that the bowel was again the likely source. If Lee et al had read this paper they may have considered the bowel perforation scenario to be the most plausible cause.

They do seem to have the first report of a case of portal vein thrombophlebitis; however, so I will not complain too much, as I have learnt yet another potential adverse effect following acupuncture, albeit secondary to infection rather than directly resulting from the needle penetration.

Whilst on the subject of deep infections related to needling. Psoas abscesses have been reported on a number of occasions, and I am not really sure why these are not a subset of retroperitoneal abscesses, since the psoas is a retroperitoneal structure. I guess the mechanisms of infection tend to be different, since infection tracking in the muscle sheath is more likely to come from the spine.

I remember writing an editorial about psoas abscesses with Adrian some years back to accompany a paper we published in Acupuncture in Medicine.[3,4] Rather immodestly, I must admit it is a good read, and highlights all the usual issues in these cases where acupuncture is blamed as the source of infection. Rather than repeat the arguments, I will provide a direct link to the editorial here in case you have an extra few minutes spare.

The editorial highlights two further case reports of epidural abscesses, which I have reviewed today.[5,6] They are both hard to interpret in terms of causality. For example, a patient may have back pain that is getting worse because of a rare spontaneous blood borne infection in the spine, they then seek acupuncture treatment for the symptoms before they have become systemically unwell. Acupuncture is then blamed as it occurred before the infection became apparent. Where 10cm needles have been inserted in the back, and bowel flora are implicated, I am fairly happy to assume it was the acupuncture.[6] But when the case involves Staphylococcus aureus, and the needling was likely to have been much less heroic (as in a licenced practitioner in the US), I am less certain that the acupuncture should be automatically blamed.[5]

Since our editorial in 2009, there have been a few more reports. There is a really nice bit of correspondence in the journal Haemodialysis International about a case of psoas abscess where acupuncture is blamed.[7] It beautifully highlights the likely misattribution of cause. A 53-year-old haemodialysis patient slipped and injured her back 15 days before admission with sepsis. She had a 7.8cm left sided psoas abscess. She had received acupuncture for her back pain 3 days before admission. Another correspondent in the journal pointed out that injury to the back is a recognised cause of abscess formation, and 3 days is a remarkably short time to develop a 7/8cm abscess.[8] I agree!

More frustration and uncertainty for us!

Another case, this time published in the Journal of Emergency Medicine, reported bilateral psoas abscesses growing Staphylococcus aureus (MRSA specifically) following acupuncture.[9] The authors happily blame acupuncture, but fail to consider a possible mechanism. Looking at the CT images in this case, it seems that blood borne spread is the only way of getting such deep abscesses bilaterally. Acupuncture may have caused bacteraemia with MRSA, but a host of other things could also do the same. Acupuncture sticks in the memory because it has agency, and the patient recalled that his symptoms deteriorated after the treatment. We do not know how long after unfortunately, as it is not reported. More frustration and uncertainty for us!

Finally, we published a further case in Acupuncture in Medicine in 2015.[10] Reading over the case again I can see that we pushed the authors to argue the case for attribution to acupuncture – we even made them use the subheading ‘Causal relationship’. In this case we get more detail about the acupuncture than is usual in such reports. We have the number of sessions, as well as the location and depth of needling. The authors point out that while the practitioner reported hand washing and skin disinfection, they did not wear gloves or a mask! That made me chuckle a bit! Imagine how the contextual effects of your acupuncture treatment would alter if you pulled on gloves and donned a mask to cover your face before leaning ominously over your victim with long shiny needles.

Anyway, in this last case the needle depth was reported as 3-4cm, and yet the authors insist that direct inoculation of the responsible Group C Streptococcus into the L5/S1 disc was the only credible cause. I honestly doubt that is possible.

‘Keep calm and carry on’

My curiosity about this last case we published led me to have a look at the paper copy of that issue – I know, it takes you back, doesn’t it, leafing through paper journals? It turns out that it was Adrian’s last issue as EiC (Editor in Chief), and so I was sure he would say something in his ‘In this issue’ piece at the front. He did, and it was all about turf wars in Korea between Western medicine doctors and Korean medicine doctors.[11] As part of these there was a notable rise in adverse event reporting by conventional physicians concerning acupuncture with a distinctly critical undertone. Ah ha then, have we uncovered a motivation for insisting that it must have been the acupuncture?

Adrian urged us to ‘Keep calm and carry on’, as he handed over the journal reins to David.


1         Lee H, Sung K, Cho J. Retroperitoneal abscess with pylephlebitis caused by lumbar acupuncture: a case report. BMC Surg 2019;19:145. doi:10.1186/s12893-019-0613-6

2         Cho YP, Jang HJ, Kim JS, et al. Retroperitoneal abscess complicated by acupuncture: case report. J Korean Med Sci 2003;18:756–7. doi:10.3346/jkms.2003.18.5.756

3         White A, Cummings M. Psoas Abscess and Acupuncture. Acupunct Med 2009;27:48–9. doi:10.1136/aim.2009.000786

4         Ogasawara M, Oda K, Yamaji K, et al. Polyarticular Septic Arthritis with Bilateral Psoas Abscesses following Acupuncture. Acupunct Med 2009;27:81–2. doi:10.1136/aim.2008.000141

5         Garcia AA, Venkataramani A. Bilateral psoas abscesses following acupuncture. West J Med 1994;161:90.

6         Bang MS, Lim SH. Paraplegia caused by spinal infection after acupuncture. Spinal Cord 2006;44:258–9. doi:10.1038/

7         Kim JW, Kim YS. Psoas abscess formation after acupuncture in a hemodialysis patient. Hemodial Int 2010;14:343–4. doi:10.1111/j.1542-4758.2010.00460.x

8         Kim KH, Kang JW, Kim T-H, et al. Psoas abscess caused by acupuncture? Hemodial Int 2010;14:526–7. doi:10.1111/j.1542-4758.2010.00497.x

9         Kuo C-M, Wu C-K, Lien W-C. Bilateral Psoas Abscess Formation after Acupuncture. J Emerg Med 2011;40:215–6. doi:10.1016/j.jemermed.2009.02.030

10       He C, Wang T, Gu Y, et al. Unusual Case of Pyogenic Spondylodiscitis, Vertebral Osteomyelitis and Bilateral Psoas Abscesses after Acupuncture: Diagnosis and Treatment with Interventional Management. Acupunct Med 2015;33:154–7. doi:10.1136/acupmed-2014-010717

11       White A. In this Issue. Acupunct Med 2015;33:95–95. doi:10.1136/acupmed-2015-010805

Declaration of interests MC